ORCID Profile
0000-0001-6578-369X
Current Organisations
University of Connecticut
,
Australian National University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Ecology | Evolutionary Impacts of Climate Change | Ecological Impacts of Climate Change | Evolutionary Biology | Plant Biology | Terrestrial Ecology | Plant Physiology | Natural Resource Management | Ecological Applications | Plant Developmental and Reproductive Biology | Plant Physiology | Biological Adaptation | Ecology And Evolution Not Elsewhere Classified | Nutrition And Physiology | Plant Improvement (Selection, Breeding And Genetic Engineering) | Agroforestry | Management And Environment | Epigenetics (incl. Genome Methylation and Epigenomics) | Terrestrial Ecology | Conservation and Biodiversity | Palaeoecology | Life Histories (Incl. Population Ecology) | Conservation And Biodiversity | Community Ecology | Ecological Physiology | Surfacewater Hydrology | Forestry Sciences | Global Change Biology | Population, Ecological and Evolutionary Genetics | Plant Cell and Molecular Biology | Phylogeny and Comparative Analysis | Ecosystem Function | Crop and Pasture Biochemistry and Physiology | Soil Physics
ANZSRC Socio-Economic Objective (SEO)
Mountain and High Country Flora, Fauna and Biodiversity | Ecosystem Adaptation to Climate Change | Global climate change adaptation measures | Expanding Knowledge in the Biological Sciences | Ecosystem Assessment and Management of Mountain and High Country Environments | Biological sciences | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Native vegetation | Mountain and High Country Land and Water Management | Integration of farm and forestry | Primary products from plants | Hardwood plantations | Sparseland, Permanent Grassland and Arid Zone Flora, Fauna and Biodiversity | Remnant Vegetation and Protected Conservation Areas at Regional or Larger Scales | Land and water management | Flora, Fauna and Biodiversity at Regional or Larger Scales | Environmentally Sustainable Plant Production not elsewhere classified | Climate Change Adaptation Measures | Land and water management | Living resources (flora and fauna) | Integrated (ecosystem) assessment and management | Mountain and High Country Soils | Ecosystem Assessment and Management of Sparseland, Permanent Grassland and Arid Zone Environments | Living resources (flora and fauna) | Rehabilitation of Degraded Farmland, Arable Cropland and Permanent Cropland Environments |
Related Links
Publications
High temperature acclimation of C-4 photosynthesis is linked to changes in photosynthetic biochemistry
Publisher: Wiley
Date: 06-11-2007
DOI: 10.1111/J.1365-3040.2006.01605.X
Abstract: With average global temperatures predicted to increase over the next century, it is important to understand the extent and mechanisms of C4 photosynthetic acclimation to modest increases in growth temperature. To this end, we compared the photosynthetic responses of two C4 grasses (Panicum coloratum and Cenchrus ciliaris) and one C4 dicot (Flaveria bidentis) to growth at moderate (25/20 degrees C, day/night) or high (35/30 degrees C, day/night) temperatures. In all three C4 species, CO2 assimilation rates (A) underwent significant thermal acclimation, such that when compared at growth temperatures, A increased less than what would be expected given the strong response of A to short-term changes in leaf temperature. Thermal photosynthetic acclimation was further manifested by an increase in the temperature optima of A, and a decrease in leaf nitrogen content and leaf mass per area in the high- relative to the moderate-temperature-grown plants. Reduced photosynthetic capacity at the higher growth temperature was underpinned by selective changes in photosynthetic components. Plants grown at the higher temperature had lower amounts of ribulose-1,5-bisphosphate carboxylase/oxygenase and cytochrome f and activity of carbonic anhydrase. The activities of photosystem II (PSII) and phosphoenolpyruvate carboxylase were not affected by growth temperature. Chlorophyll fluorescence measurements of F. bidentis showed a corresponding decrease in the quantum yield of PSII (phi(PSII)) and an increase in non-photochemical quenching (phi(NPQ)). It is concluded that through these biochemical changes, C4 plants maintain the balance between the various photosynthetic components at each growth temperature, despite the differing temperature dependence of each process. As such, at higher temperatures photosynthetic nitrogen use efficiency increases more than A. Our results suggest C4 plants will show only modest changes in photosynthetic rates in response to changes in growth temperature, such as those expected within or between seasons, or the warming anticipated as a result of global climate change.
Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan
Publisher: Oxford University Press (OUP)
Date: 2020
Abstract: Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions the number of ‘success stories’ is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring bio ersity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a ‘horizon scan’, we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.
Beware: alien invasion. Where to next for an understanding of weed ecology?
Publisher: Wiley
Date: 10-04-2012
Germination at Extreme Temperatures: Implications for Alpine Shrub Encroachment
Publisher: MDPI AG
Date: 09-02-2021
Abstract: Worldwide, shrub cover is increasing across alpine and tundra landscapes in response to warming ambient temperatures and declines in snowpack. With a changing climate, shrub encroachment may rely on recruitment from seed occurring outside of the optimum temperature range. We used a temperature gradient plate in order to determine the germination niche of 14 alpine shrub species. We then related the range in laboratory germination temperatures of each species to long-term average temperature conditions at: (1) the location of the seed accession site and (2) across each species geographic distribution. Seven of the species failed to germinate sufficiently to be included in the analyses. For the other species, the germination niche was broad, spanning a range in temperatures of up to 17 °C, despite very low germination rates in some species. Temperatures associated with the highest germination percentages were all above the range of temperatures present at each specific seed accession site. Optimum germination temperatures were consistently within or higher than the range of maximum temperatures modelled across the species’ geographic distribution. Our results indicate that while some shrub species germinate well at high temperatures, others are apparently constrained by an inherent seed dormancy. Shrub encroachment in alpine areas will likely depend on conditions that affect seed germination at the microsite-scale, despite overall conditions becoming more suitable for shrubs at high elevations.
The thermal tolerance of photosynthetic tissues: a global systematic review and agenda for future research
Publisher: Wiley
Date: 03-12-2020
DOI: 10.1111/NPH.17052
Abstract: Understanding plant thermal tolerance is fundamental to predicting impacts of extreme temperature events that are increasing in frequency and intensity across the globe. Extremes, not averages, drive species evolution, determine survival and increase crop performance. To better prioritize agricultural and natural systems research, it is crucial to evaluate how researchers are assessing the capacity of plants to tolerate extreme events. We conducted a systematic review to determine how plant thermal tolerance research is distributed across wild and domesticated plants, growth forms and biomes, and to identify crucial knowledge gaps. Our review shows that most thermal tolerance research examines cold tolerance of cultivated species c. 5% of articles consider both heat and cold tolerance. Plants of extreme environments are understudied, and techniques widely applied in cultivated systems are largely unused in natural systems. Lastly, we find that lack of standardized methods and metrics compromises the potential for mechanistic insight. Our review provides an entry point for those new to the methods used in plant thermal tolerance research and bridges often disparate ecological and agricultural perspectives for the more experienced. We present a considered agenda of thermal tolerance research priorities to stimulate efficient, reliable and repeatable research across the spectrum of plant thermal tolerance.
Seed germination strategies: an evolutionary trajectory independent of vegetative functional traits
Publisher: Frontiers Media SA
Date: 12-10-2015
Influence of ultrasound on chemically induced gelation of micellar casein systems
Publisher: Cambridge University Press (CUP)
Date: 18-01-2013
DOI: 10.1017/S0022029912000696
Abstract: Gelation is a significant operation in dairy processing. Protein gelation can be affected by several factors such as temperature, pH, or enzyme addition. Recently, the use of ultrasonication has been shown to have a significant impact on the formation of whey protein gels. In this work, the effect of ultrasonication on the gelation of casein systems was investigated. Gels were formed by the addition of 7·6 m m Tetra Sodium Pyro Phosphate (TSPP) to 5 wt% micellar casein (MC) solutions. Sonication at 20 KHz and 31 W for up to 30 min changed the surface hydrophobicity of the proteins, whereas surface charge was unaltered. Sonication before the addition of TSPP formed a firm gel with a fine protein network and low syneresis. Conversely, sonication after TSPP addition led to an inconsistent weak-gel-like structure with high syneresis. Gel strength in both cases increased significantly after short sonication times, while the viscoelastic properties were less affected. Overall, the results showed that ultrasonication can have a significant effect on the final gel properties of casein systems.
Critical analysis of quantitative indicators of cell disruption applied to Saccharomyces cerevisiae processed with an industrial high pressure homogenizer
Publisher: Elsevier BV
Date: 2013
Biological responses to the press and pulse of climate trends and extreme events
Publisher: Springer Science and Business Media LLC
Date: 29-07-2017
Assessing the components of adaptive capacity to improve conservation and management efforts under global change
Publisher: Wiley
Date: 29-04-2015
DOI: 10.1111/COBI.12522
Abstract: Natural-resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural-resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and ex les from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait- and triage-based approaches encompassing the oft-overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco-physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural-resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real-world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions.
Seedling root anatomy and morphology: an examination of ecological differentiation with rainfall using phylogenetically independent contrasts
Publisher: Springer Science and Business Media LLC
Date: 2002
Abstract: We examined patterns of seedling root architecture, morphology and anatomy in Australian perennial plants chosen as phylogenetically independent contrasts (PICs) for rainfall in the areas they inhabit. Our objective was to assess whether there are consistent evolutionary patterns in structure of seedling root systems in species from different rainfall environments when examined across multiple evolutionary lineages. Seedlings were grown to a standardised developmental stage under controlled conditions. We found that seedling root systems of species restricted to low rainfall environments are characterised by greater proportional allocation to main root axis and have proportionally smaller main root axis diameter and areas of stele and xylem. Species of low rainfall environments also had higher specific root length (SRL) of the main axis, but lower SRL when the entire root system was considered. Seedling root system elongation rates were higher in species of high rainfall relative to those of low rainfall environments, paralleling expected differences in relative growth rate. The higher root system elongation rates in species of high rainfall environments were associated with greater numbers of growing tips in the root system, but not with differences in elongation rates of in idual tips, relative to species of low rainfall environments.
Space and time dependence of temperature and freezing in evergreen leaves
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/FP02037
Abstract: Infrared video thermography was used to study space and time dependence of freezing in intact, attached leaves of snow gum (Eucalyptus pauciflora Sieb. ex Spreng.) seedlings. Freezing initiated in the midvein and spread through the apoplast at 10 mm s–1. Freezing of apoplastic water was detected by a local, rapid increase in temperature, and was followed by a slower increase in leaf temperature to the equilibrium freezing temperature as symplastic water moved from cells to extracellular sites of ice formation. The duration of freezing varied with position, leaf thickness and water content. Most of the cellular water in the leaf tip and margins froze quickly, while freezing was slower near the petiole and midvein. Regions that had frozen more rapidly then began to cool more rapidly, producing steep gradients in leaf temperatures and hence also freeze-induced dehydration. Thus, spatial variation in physical properties of leaves could affect the distribution of minimum leaf temperatures, and hence, the distribution and extent of damage due to freeze-induced dehydration. These results are consistent with patterns of freezing damage in autumn when the duration of freezing may be insufficient for the whole leaf to freeze before sunrise, and may explain the general observation of increased leaf water content and thickness with altitude.
Understanding the importance of intrapopulation functional variability and phenotypic plasticity in Quercus suber
Publisher: Springer Science and Business Media LLC
Date: 08-04-2015
Effects of warming temperatures on germination responses and trade-offs between seed traits in an alpine plant
Publisher: Wiley
Date: 27-10-2023
Abstract: Climate warming may affect multiple aspects of plant life history, including important factors such as germination responses and the key trade‐off between offspring size and number. As a case study to address these concepts, we used an alpine plant (waxy bluebell, Wahlenbergia ceracea C anulaceae) that shows plasticity to warming in seed traits and in which seed dormancy status regulates germination. We chose an alpine species because alpine environments are ecosystems particularly under threat by climate change. We conducted germination assays under cool and warm temperatures using seeds produced by in iduals that were grown under historical (cooler) and future (warmer) temperature scenarios. We assessed the presence of a seed size versus number trade‐off, and then examined the effects of seed number and size on germination percentage, the fractions of dormant and viable seeds, and germination velocity. Further, we examined whether warming during parental growth and during germination affected these relationships. We found evidence for a seed size versus number trade‐off only under historical parental temperatures. Indeed, under future growth temperatures parental plants produced fewer and smaller seeds and there was no evidence of a trade‐off. However, the reductions in both seed traits under warming did not affect germination, despite correlations of seed size and number with germination traits. Warming increased germination, particularly of larger seeds, but overall, it resulted in more than fourfold reductions in parental fitness. Synthesis . Our study shows the importance of growth conditions when evaluating the seed size versus number trade‐off. Stressful conditions, such as warmer temperatures, can restrain the ability of plants to reach optimal investment in reproduction, masking the trade‐off. By analysing responses across the whole life cycle, we show here an overall detrimental effect of warming, highlighting the potential risk of climate change for Wahlenbergia ceracea , and, potentially, for alpine plant communities more widely.
Intraspecific Competition in Chenopodium album Varies with Resource Availability
Publisher: JSTOR
Date: 07-1995
DOI: 10.2307/2426486
Influence of previous frost damage on tree growth and insect herbivory of Eucalyptus globulus globulus
Publisher: Wiley
Date: 10-2001
Habitat-specific responses of leaf traits to soil water conditions in species from a novel alpine swamp meadow community
Publisher: Oxford University Press (OUP)
Date: 2015
The challenges facing early-career researchers pursuing overseas positions during a global pandemic
Publisher: Springer Science and Business Media LLC
Date: 14-10-2021
Geographic variation and plasticity to water and nutrients in Pelargonium australe
Publisher: Wiley
Date: 13-08-2007
DOI: 10.1111/J.1469-8137.2007.02157.X
Abstract: Here, patterns of phenotypic plasticity and trait integration of leaf characteristics in six geographically discrete populations of the perennial herb Pelargonium australe were compared. It was hypothesized that populations would show local adaptation in trait means, but similar patterns of plasticity and trait integration. Further, it was questioned whether phenotypic plasticity was positively correlated with environmental heterogeneity and whether plasticity for water-use traits in particular was adaptive. Seedlings were grown in a glasshouse at six combinations of water and nutrient availability. Leaf anatomical, morphological and gas exchange traits were measured. High amounts of plasticity in leaf traits were found in response to changes in growth conditions and there was evidence of local adaptation among the populations. While there were significant correlations between plasticity and environmental heterogeneity, not all were positive. Notably, patterns of plasticity and trait integration varied significantly among populations. Despite that variation, some of the observed plasticity was adaptive: fitness was correlated with conservative water use when water was limiting. Pelargonium arrived in Australia approximately 5 million yr ago. It is concluded here that high amounts of plasticity, in some cases adaptive, and weak integration among traits may be key to the spread and success of this species.
How plant life-history and ecological traits relate to species rarity and commonness at varying spatial scales
Publisher: Wiley
Date: 06-2002
Are postbiotics key to the potential benefits of fermented foods?
Publisher: Elsevier BV
Date: 06-2023
Supporting the adaptive capacity of species through more effective knowledge exchange with conservation practitioners
Publisher: Wiley
Date: 06-07-2021
DOI: 10.1111/EVA.13266
Abstract: There is an imperative for conservation practitioners to help bio ersity adapt to accelerating environmental change. Evolutionary biologists are well‐positioned to inform the development of evidence‐based management strategies that support the adaptive capacity of species and ecosystems. Conservation practitioners increasingly accept that management practices must accommodate rapid environmental change, but harbour concerns about how to apply recommended changes to their management contexts. Given the interest from both conservation practitioners and evolutionary biologists in adjusting management practices, we believe there is an opportunity to accelerate the required changes by promoting closer collaboration between these two groups. We highlight how evolutionary biologists can harness lessons from other disciplines about how to foster effective knowledge exchange to make a substantive contribution to the development of effective conservation practices. These lessons include the following: (1) recognizing why practitioners do and do not use scientific evidence (2) building an evidence base that will influence management decisions (3) translating theory into a format that conservation practitioners can use to inform management practices and (4) developing strategies for effective knowledge exchange. Although efforts will be required on both sides, we believe there are rewards for both practitioners and evolutionary biologists, not least of which is fostering practices to help support the long‐term persistence of species.
Intraspecific trait variation in alpine plants relates to their elevational distribution
Publisher: Wiley
Date: 24-02-2022
Abstract: Climate warming is shifting the distributions of mountain plant species to higher elevations. Cold‐adapted plant species are under increasing pressure from novel competitors that are encroaching from lower elevations. Plant capacity to adjust to these pressures may be measurable as variation in trait values within a species. In particular, the strength and patterns of intraspecific trait variation along abiotic and biotic gradients can inform us whether and how species can adjust their anatomy and morphology to persist in a changing environment. Here, we tested whether species specialized to high elevations or with narrow elevational ranges show more conservative (i.e. less variable) trait responses across their elevational distribution, or in response to neighbours, than species from lower elevations or with wider elevational ranges. We did so by studying intraspecific trait variation of 66 species along 40 elevational gradients in four countries in both hemispheres. As an indication of potential neighbour interactions that could drive trait variation, we also analysed plant species’ height ratio, its height relative to its nearest neighbour. Variation in alpine plant trait values over elevation differed depending on a species’ median elevation and the breadth of its elevational range, with species with lower median elevations and larger elevational range sizes showing greater trait variation, i.e. a steeper slope in trait values, over their elevational distributions. These effects were evidenced by significant interactions between species’ elevation and their elevational preference or range for several traits: vegetative height, generative height, specific leaf area and patch area. The height ratio of focal alpine species and their neighbours decreased in the lower part of their distribution because neighbours became relatively taller at lower elevations. In contrast, species with lower elevational optima maintained a similar height ratio with neighbours throughout their range. Synthesis . We provide evidence that species from lower elevations and those with larger range sizes show greater intraspecific trait variation, which may indicate a greater ability to respond to environmental changes. Also, larger trait variation of species from lower elevations may indicate stronger competitive ability of upslope shifting species, posing one further threat to species from higher ranges.
Do invasive species show higher phenotypic plasticity than native species and, if so, is it adaptive? A meta-analysis
Publisher: Wiley
Date: 14-02-2011
DOI: 10.1111/J.1461-0248.2011.01596.X
Abstract: Do invasive plant species have greater phenotypic plasticity than non-invasive species? And, if so, how does this affect their fitness relative to native, non-invasive species? What role might this play in plant invasions? To answer these long-standing questions, we conducted a meta-analysis using data from 75 invasive/non-invasive species pairs. Our analysis shows that invasive species demonstrate significantly higher phenotypic plasticity than non-invasive species. To examine the adaptive benefit of this plasticity, we plotted fitness proxies against measures of plasticity in several growth, morphological and physiological traits to test whether greater plasticity is associated with an improvement in estimated fitness. Invasive species were nearly always more plastic in their response to greater resource availability than non-invasives but this plasticity was only sometimes associated with a fitness benefit. Intriguingly, non-invasive species maintained greater fitness homoeostasis when comparing growth between low and average resource availability. Our finding that invasive species are more plastic in a variety of traits but that non-invasive species respond just as well, if not better, when resources are limiting, has interesting implications for predicting responses to global change.
Amino Acids as Carbon Capture Solvents: Chemical Kinetics and Mechanism of the Glycine + CO2 Reaction
Publisher: American Chemical Society (ACS)
Date: 26-06-2013
DOI: 10.1021/EF400413R
Growth response following green crown pruning in plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana
Publisher: Canadian Science Publishing
Date: 04-2008
DOI: 10.1139/X07-185
Abstract: Pruning of live branches is performed to enhance wood quality in plantation trees. Stem, branch and wood properties may be altered following pruning from below, but the extent and duration of such effects are unknown for many plantation Eucalyptus species. The effect of 0%, 20%, 50%, and 70% green crown length removal on growth and wood quality was examined in 3.5-year-old plantation-grown Eucalyptus pilularis Sm. (blackbutt) and Eucalyptus cloeziana F. Muell. (Gympie messmate) trees on two subtropical sites in eastern Australia. Growth increment of the stem at breast height was not affected by 20% crown removal. However, stem increment at breast height was reduced for up to 8 months with 50% crown removal and up to 12 months with 70% crown removal. Pruning had no impact on height growth. However, the height of trees pruned to 70%, relative to the height of the surrounding unpruned trees, was temporarily reduced 12 months after pruning in both species. Stem form, stem taper, wood density, and residual branch growth above the pruned zone were unaffected by pruning. Owing to the fast vertical crown expansion, trees were able to rapidly compensate for leaf area removal without long-term reductions in stem growth. The implications for management operations utilizing pruning as a means of enhancing timber quality are discussed.
Detection of changes in regional colonic fermentation in response to supplementing a low FODMAP diet with dietary fibres by hydrogen concentrations, but not by luminal pH
Publisher: Wiley
Date: 30-06-2023
DOI: 10.1111/APT.17629
Abstract: Carbohydrate fermentation plays a pivotal role in maintaining colonic health with excessive proximal and deficient distal fermentation being detrimental. To utilise telemetric gas‐ and pH‐sensing capsule technologies for defining patterns of regional fermentation following dietary manipulations, alongside conventional techniques of measuring fermentation. In a double‐blind crossover trial, 20 patients with irritable bowel syndrome were fed low FODMAP diets that included no extra fibre (total fibre content 24 g/day), or additional poorly fermented fibre, alone (33 g/day) or with fermentable fibre (45 g/day) for 2 weeks. Plasma and faecal biochemistry, luminal profiles defined by tandem gas‐ and pH‐sensing capsules, and faecal microbiota were assessed. Plasma short‐chain fatty acid (SCFA) concentrations (μmol/L) were median (IQR) 121 (100–222) with fibre combination compared with 66 (44–120) with poorly fermented fibre alone ( p = 0.028) and 74 (55–125) control ( p = 0.069), but no differences in faecal content were observed. Luminal hydrogen concentrations (%), but not pH, were higher in distal colon (mean 4.9 [95% CI: 2.2–7.5]) with fibre combination compared with 1.8 (0.8–2.8) with poorly fermented fibre alone ( p = 0.003) and 1.9 (0.7–3.1) control ( p = 0.003). Relative abundances of saccharolytic fermentative bacteria were generally higher in association with supplementation with the fibre combination. A modest increase in fermentable plus poorly fermented fibres had minor effects on faecal measures of fermentation, despite increases in plasma SCFA and abundance of fermentative bacteria, but the gas‐sensing capsule, not pH‐sensing capsule, detected the anticipated propagation of fermentation distally in the colon. The gas‐sensing capsule technology provides unique insights into localisation of colonic fermentation. Trial registration: ACTRN12619000691145.
Variation in snow cover drives differences in frost resistance in seedlings of the alpine herb Aciphylla glacialis
Publisher: Elsevier BV
Date: 10-2014
A randomized dietary intervention to increase colonic and peripheral blood SCFAs modulates the blood B- and T-cell compartments in healthy humans
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1093/AJCN/NQAC246
Leaf cooling curves: measuring leaf temperature in sunlight
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/FP05300
Abstract: Despite the obvious benefits of using thermography under field conditions, most infrared studies at the leaf level are generally conducted in the laboratory. One reason for this bias is that accuracy can potentially be compromised in sunlight because reflected radiation from the leaf might affect the calculation of the temperature measurement. We have developed a method for measuring leaf temperature in sunlight by using thermal imagery to generate cooling curves from which the time constant for cooling, τ, can be calculated. The original temperature of the sunlit leaf may be determined by extrapolating backwards in time. In the absence of specular reflection, there is close agreement between the extrapolated sunlit temperature and the sunlit temperature recorded by the camera. However, when reflected radiation is high, the difference between the initial (incorrect) temperature determined from the sunlit image and the temperature extrapolated from the cooling curve can be 2°C. Notably, our results demonstrate a close agreement between the extrapolated sunlit temperature and the temperature of the leaf approximately 1 s after being shaded, suggesting that this shaded image provides a good estimate of the original sunlit temperature. Thus, our technique provides two means for measuring leaf surface temperature in sunlight.
EGRINs (Environmental Gene Regulatory Influence Networks) in Rice That Function in the Response to Water Deficit, High Temperature, and Agricultural Environments
Publisher: Oxford University Press (OUP)
Date: 21-09-2016
DOI: 10.1105/TPC.16.00158
Sex ratio variation and spatial distribution of Siparuna grandiflora, a tropical dioecious shrub
Publisher: Springer Science and Business Media LLC
Date: 08-06-1998
Abstract: Populations of dioecious plant species often exhibit biased sex ratios. Such biases may arise as a result of sex-based differences in life history traits, or as a result of spatial segregation of the sexes. Of these, sex-based differentiation in life history traits is likely to be the most common cause of bias. In dioecious species, selection can act upon the sexes in a somewhat independent way, leading to differentiation and evolution toward sex-specific ecological optima. I examined sex ratio variation and spatial distribution of the tropical dioecious shrub Siparuna grandiflora to determine whether populations exhibited a biased sex ratio, and if so, whether the bias could be explained in terms of non-random spatial distribution or sex-based differentiation in life history traits. Sex ratio bias was tested using contingency tables, a logistic regression approach was utilized to examine variation in life history traits, and spatial distributions were analyzed using Ripley's K, a second-order neighborhood analysis. I found that although populations of S. grandiflora have a male-biased sex ratio within and among years, there was no evidence of spatial segregation of the sexes. Rather, the sex ratio bias was shown to result primarily from sex-based differentiation in life history traits males reproduce at a smaller size and more frequently than females. The sexes also differ in the relationship between plant size and reproductive frequency. Light availability was shown to affect reproductive activity in both sexes, though among infrequently flowering plants, females require higher light levels than males to flower. The results of this study demonstrate that ecologically significant sex-based differentiation has evolved in S. grandiflora.
Association Between the Gut Microbiome and Their Metabolites With Human Blood Pressure Variability
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2022
DOI: 10.1161/HYPERTENSIONAHA.122.19350
Abstract: Blood pressure (BP) variability is an independent risk factor for cardiovascular events. Recent evidence supports a role for the gut microbiota in BP regulation. However, whether the gut microbiome is associated with BP variability is yet to be determined. Here, we aimed to investigate the interplay between the gut microbiome and their metabolites in relation to BP variability. Ambulatory BP monitoring was performed in 69 participants from Australia (55.1% women mean±SD, 59.8±7.26 years body mass index, 25.2±2.83 kg/m 2 ). These data were used to determine nighttime dipping, morning BP surge (MBPS) and BP variability as SD. The gut microbiome was determined by 16S ribosomal RNA (rRNA) sequencing and metabolite levels by gas chromatography. We identified specific taxa associated with systolic BP variability, nighttime dipping, and MBPS. Notably, Alistipesfinegoldii and Lactobacillus spp. were only present in participants within the normal ranges of BP variability, MBPS and dipping, while Prevotella spp. and Clostridium spp., were found to be present in extreme dippers and the highest quartiles of BP SD and MBPS. There was a negative association between MBPS and microbial α- ersity (r=−0.244, P =0.046). MBPS was also negatively associated with plasma levels of microbial metabolites called short-chain fatty acids (r=−0.305, P =0.020), particularly acetate (r=−0.311, P =0.017). Gut microbiome ersity, levels of microbial metabolites, and the bacteria Alistipesfinegoldii and Lactobacillus were associated with lower BP variability and Clostridium and Prevotella with higher BP variability. Thus, our findings suggest the gut microbiome and metabolites may be involved in the regulation of BP variability.
Climate change: Alpine shrubs as ecosystem engineers
Publisher: Wiley
Date: 21-04-2019
DOI: 10.1111/AEC.12727
Climate change: alters plant recruitment from seed
Publisher: Wiley
Date: 06-03-2019
DOI: 10.1111/AEC.12728
Do thick leaves avoid thermal damage in critically low wind speeds?
Publisher: Wiley
Date: 02-2012
DOI: 10.1111/J.1469-8137.2012.04058.X
Abstract: Transient lulls in air movement are rarely measured, but can cause leaf temperature to rise rapidly to critical levels. The high heat capacity of thick leaves can d this rapid change in temperature. However, little is known about the extent to which increased leaf thickness can reduce thermal damage, or how thick leaves would need to be to have biological significance. We evaluated quantitatively the contribution of small increases in leaf thickness to the reduction in thermal damage during critically low wind speeds under desert conditions. We employed a numerical model to investigate the effect of thickness relative to transpiration, absorptance and leaf size on damage avoidance. We used measured traits and thermotolerance thresholds of real leaves to calculate the leaf temperature response to naturally occurring variable low wind speed. Our results demonstrated that an increase in thickness of only fractions of a millimetre can prevent excursions to damaging high temperatures. This d ing effect of increased thickness was greatest when other means of reducing leaf temperature (transpiration, reflectance or reduced size) were lacking. For perennial desert flora, we propose that increased leaf thickness is important in decreasing the incidence of extreme heat stress and, in some species, in enhancing long-term survival.
PHYLOGENETIC INFLUENCES ON LEAF TRAIT INTEGRATION IN PELARGONIUM (GERANIACEAE) : CONVERGENCE, DIVERGENCE, AND HISTORICAL ADAPTATION TO A RAPIDLY CHANGING CLIMATE
Publisher: Wiley
Date: 07-2013
DOI: 10.3732/AJB.1200526
Abstract: Trait integration may improve prediction of species and lineage responses to future climate change more than in idual traits alone, particularly when analyses incorporate effects of phylogenetic relationships. The South African genus Pelargonium contains ergent major clades that have radiated along the same seasonal aridity gradient, presenting the opportunity to ask whether patterns of evolution in mean leaf trait values are achieved through the same set of coordinated changes among traits in each clade. Seven leaf traits were measured on field-collected leaves from one-third of the species (98) of the genus. Trait relationships were examined using phylogenetic regression within major clades. Disparity analysis determined whether the course of trait evolution paralleled historical climate change events. Divergence in mean trait values between sister clades A1 and A2 was consistent with expectations for leaves differing in longevity, despite strong similarity between clades in trait interactions. No traits in either clade exhibited significant relationships with multivariate climate axes, with one exception. Species in clades C and A2 included in this study occupied similar environments. These clades had similar values of in idual trait means, except for δ(13)C, but they exhibited distinctive patterns of trait integration. Differing present-day patterns of trait integration are consistent with interpretations of adaptive responses to the prevailing climate at the time of each clade's origin. These differing patterns of integration are likely to exert strong effects on clade-level responses to future climate change in the winter rainfall region of South Africa.
The influence of site quality on timing of pruning in Eucalyptus pilularis and Eucalyptus cloeziana plantations
Publisher: Informa UK Limited
Date: 03-2013
Effects of initial planting density on branch development in 4-year-old plantation grown Eucalyptus pilularis and Eucalyptus cloeziana trees
Publisher: Elsevier BV
Date: 11-2007
Himalayan-Tibetan Plateau Uplift Drives Divergence of Polyploid Poppies: Meconopsis Viguier (Papaveraceae)
Publisher: Public Library of Science (PLoS)
Date: 16-06-2014
Population structure and diversity in sexual and asexual populations of the pathogenic fungus Melampsora lini
Publisher: Wiley
Date: 06-2008
Screening dietary fibres for fermentation characteristics and metabolic profiles using a rapid in vitro approach: implications for irritable bowel syndrome
Publisher: Cambridge University Press (CUP)
Date: 08-10-2020
DOI: 10.1017/S0007114520003943
Abstract: The therapeutic value of specific fibres is partly dependent on their fermentation characteristics. Some fibres are rapidly degraded with the generation of gases that induce symptoms in patients with irritable bowel syndrome (IBS), while more slowly or non-fermentable fibres may be more suitable. More work is needed to profile a comprehensive range of fibres to determine suitability for IBS. Using a rapid in vitro fermentation model, gas production and metabolite profiles of a range of established and novel fibres were compared. Fibre substrates ( n 15) were added to faecal slurries from three healthy donors for 4 h with gas production measured using real-time headspace s ling. Concentrations of SCFA and ammonia were analysed using GC and enzymatic assay, respectively. Gas production followed three patterns: rapid (≥60 ml/g over 4 h) for fructans, carrot fibre and maize-derived xylo-oligosaccharide (XOS) mild (30–60 ml/g) for partially hydrolysed guar gum, almond shell-derived XOS and one type of high-amylose resistant starch 2 (RS2) and minimal (no differences with blank controls) for methylcellulose, another high-amylose RS2, acetylated or butyrylated RS2, RS4, acacia gum and sugarcane bagasse. Gas production correlated positively with total SCFA ( r 0·80, P 0·001) and negatively with ammonia concentrations ( r –0·68, P 0·001). Proportions of specific SCFA varied: fermentation of carrot fibre, XOS and acetylated RS2 favoured acetate, while fructans favoured butyrate. Gas production and metabolite profiles differed between fibre types and within fibre classes over a physiologically relevant 4-h time course. Several fibres resisted rapid fermentation and may be candidates for clinical trials in IBS patients.
Production and faecal fermentation of pentose oligomers of hemicellulose: Study of variables influencing bioprocess efficiency
Publisher: Elsevier BV
Date: 11-2019
Aciphylla glacialis mortality, growth and frost resistance: a field warming experiment
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/BT19034
Abstract: Decreasing snow depth and earlier snowmelt in alpine regions are expected to expose plants to a greater range of thermal extremes. Thus, paradoxically, in addition to increasing mean temperatures, aseasonal frost is likely to emerge as a major determinant of plant survival and development under a warming climate. Through the use of open top chambers, we assessed the effects of simulated warming on seedlings of the alpine herb Aciphylla glacialis (F.Muell.) Benth, sourced from provenances that vary in thermal characteristics. We hypothesised that seedlings grown at elevated temperature would have reduced survival and lower freezing resistance, but that in iduals that did survive would show increased growth. Further, we hypothesised that seedlings sourced from the lower-elevation sites, where temperatures are more variable, would exhibit lower mortality at warmed conditions than those from sites with narrower thermal ranges. Warmed conditions significantly increased seedling mortality but those that survived grew slightly taller than their ambient counterparts, with no impact on leaf production or photosynthetic efficiency. Although the warming treatment did not influence temperature minimums, which would have allowed us to assess the impact of aseasonal frosts, there was no effect on freezing resistance. Contrary to our expectations, there was little evidence of variation among provenances. Our results indicate that a warmer climate with more extreme events may lead to a reduction in seedling establishment and survival however, seedlings that do survive and establish are unlikely to express any lingering detrimental effects.
Seeds at risk: How will a changing alpine climate affect regeneration from seeds in alpine areas?
Publisher: Springer Science and Business Media LLC
Date: 10-09-2015
One hundred research questions in conservation physiology for generating actionable evidence to inform conservation policy and practice
Publisher: Oxford University Press (OUP)
Date: 2021
Abstract: Environmental change and bio ersity loss are but two of the complex challenges facing conservation practitioners and policy makers. Relevant and robust scientific knowledge is critical for providing decision-makers with the actionable evidence needed to inform conservation decisions. In the Anthropocene, science that leads to meaningful improvements in bio ersity conservation, restoration and management is desperately needed. Conservation Physiology has emerged as a discipline that is well-positioned to identify the mechanisms underpinning population declines, predict responses to environmental change and test different in situ and ex situ conservation interventions for erse taxa and ecosystems. Here we present a consensus list of 10 priority research themes. Within each theme we identify specific research questions (100 in total), answers to which will address conservation problems and should improve the management of biological resources. The themes frame a set of research questions related to the following: (i) adaptation and phenotypic plasticity (ii) human–induced environmental change (iii) human–wildlife interactions (iv) invasive species (v) methods, biomarkers and monitoring (vi) policy, engagement and communication (vii) pollution (viii) restoration actions (ix) threatened species and (x) urban systems. The themes and questions will hopefully guide and inspire researchers while also helping to demonstrate to practitioners and policy makers the many ways in which physiology can help to support their decisions.
Effects of reduced winter duration on seed dormancy and germination in six populations of the alpine herb Aciphyllya glacialis (Apiaceae)
Publisher: Oxford University Press (OUP)
Date: 30-05-2014
High self-pollen transfer and low fruit set in buzz-pollinated Dianella revoluta (Phormiaceae)
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/BT03139
Abstract: We used pollinator observation, flower manipulation, controlled pollination and pollen-tube analysis to better understand the reproductive ecology of Dianella revoluta R.Br., a common species known to have depressed fruit set at fragmented sites. This buzz-pollinated species was found to receive large quantities of self-pollen even during a single pollinator visit, but is only partially self-compatible. This may be the first direct demonstration of pollinator-facilitated, autogamous self-pollen transfer accounting for a significant proportion of stigmatic pollen load. Frequent high self-pollen transfer may account for the observed low rate of fruit development in open-pollinated flowers. Self-pollen tubes reached the base of the style in comparable numbers and at the same rate as outcross pollen tubes, with no sign of pollen-tube competition favouring outcross pollen. Barriers to greater self-fertility occur late, probably through early abortion of selfed ovules. We also investigated what impact overlapping distribution with D. longifolia may have on D. revoluta pollination and reproduction. Although these species shared pollinators, they differed in terms of frequency of visits. There was also separation of floral phenology within the course of a day.
THE HOST BIAS OF THREE EPIPHYTIC AERIDINAE ORCHID SPECIES IS REFLECTED, BUT NOT EXPLAINED, BY MYCORRHIZAL FUNGAL ASSOCIATIONS
Publisher: Wiley
Date: 04-2013
DOI: 10.3732/AJB.1200411
Abstract: The three co-occurring epiphytic orchid species, Sarcochilus hillii, Plectorrhiza tridentata, and Sarcochilus parviflorus vary in host specificity all are found predominantly on the tree Backhousia myrtifolia but some also associate with a broad range of species. Despite this specialization, no fitness advantage has been detected for adult orchid plants growing on the preferred host. Therefore, we predicted that the host specialization of these orchid species is a consequence of a bias toward particular orchid mycorrhizal fungi, which are in turn biased toward particular woody plant species. To test this hypothesis, we s led representatives of each orchid species on B. myrtifolia and other host species across sites. Rhizoctonia-like fungi were isolated from orchid roots and identified using molecular markers. Three groups of fungi were identified, and the orchid species varied in their specificity for these. All fungal groups were found on the host B. myrtifolia yet at all sites, only one orchid species, S. hillii, associated with all three groups. Our results demonstrate that these orchid species did vary in their mycorrhizal specificity however, the distribution of their mycorrhizal associates did not directly explain their host associations. Rather, we propose that the mycorrhizal relationship of these orchid species is complex and have suggested future avenues of research.
Tolerance of Warmer Temperatures Does Not Confer Resilience to Heatwaves in an Alpine Herb
Publisher: Frontiers Media SA
Date: 23-02-2021
Abstract: Climate change is generating both sustained trends in average temperatures and higher frequency and intensity of extreme events. This poses a serious threat to bio ersity, especially in vulnerable environments, like alpine systems. Phenotypic plasticity is considered to be an adaptive mechanism to cope with climate change in situ , yet studies of the plastic responses of alpine plants to high temperature stress are scarce. Future weather extremes will occur against a background of warmer temperatures, but we do not know whether acclimation to warmer average temperatures confers tolerance to extreme heatwaves. Nor do we know whether populations on an elevational gradient differ in their tolerance or plasticity in response to warming and heatwave events. We investigated the responses of a suite of functional traits of an endemic Australian alpine herb, Wahlenbergia ceracea , to combinations of predicted future (warmer) temperatures and (relative) heatwaves. We also tested whether responses differed between high- vs. low-elevation populations. When grown under warmer temperatures, W. ceracea plants showed signs of acclimation by means of higher thermal tolerance ( T crit , T 50 , and T max ). They also invested more in flower production, despite showing a concurrent reduction in photosynthetic efficiency ( F v / F m ) and suppression of seed production. Heatwaves reduced both photosynthetic efficiency and longevity. However, we found no evidence that acclimation to warmer temperatures conferred tolerance of the photosynthetic machinery to heatwaves. Instead, when exposed to heatwaves following warmer growth temperatures, plants had lower photosynthetic efficiency and underwent a severe reduction in seed production. High- and low-elevation populations and families exhibited limited genetic variation in trait means and plasticity in response to temperature. We conclude that W. ceracea shows some capacity to acclimate to warming conditions but there is no evidence that tolerance of warmer temperatures confers any resilience to heatwaves.
Drivers of thermal tolerance breadth of plants across contrasting biomes: do mean or seasonality in climate indices matter more?
Publisher: Cold Spring Harbor Laboratory
Date: 03-10-2023
Third dose COVID-19 mRNA vaccine enhances IgG4 isotype switching and recognition of Omicron subvariants by memory B cells after mRNA but not adenovirus priming
Publisher: Cold Spring Harbor Laboratory
Date: 18-09-2023
Connecting research and practice to enhance the evolutionary potential of species under climate change
Publisher: Wiley
Date: 03-01-2023
DOI: 10.1111/CSP2.12855
Abstract: Resource managers have rarely accounted for evolutionary dynamics in the design or implementation of climate change adaptation strategies. We brought the research and management communities together to identify challenges and opportunities for applying evidence from evolutionary science to support on‐the‐ground actions intended to enhance species' evolutionary potential. We amalgamated input from natural‐resource practitioners and interdisciplinary scientists to identify information needs, current knowledge that can fill those needs, and future avenues for research. Three focal areas that can guide engagement include: (1) recognizing when to act, (2) understanding the feasibility of assessing evolutionary potential, and (3) identifying best management practices. Although researchers commonly propose using molecular methods to estimate genetic ersity and gene flow as key indicators of evolutionary potential, we offer guidance on several additional attributes (and their proxies) that may also guide decision‐making, particularly in the absence of genetic data. Finally, we outline existing decision‐making frameworks that can help managers compare alternative strategies for supporting evolutionary potential, with the goal of increasing the effective use of evolutionary information, particularly for species of conservation concern. We caution, however, that arguing over nuance can generate confusion instead, dedicating increased focus on a decision‐relevant evidence base may better lend itself to climate adaptation actions.
Environmental gene regulatory influence networks in rice (Oryza sativa):response to water deficit, high temperature and agricultural environments
Publisher: Cold Spring Harbor Laboratory
Date: 03-03-2016
DOI: 10.1101/042317
Abstract: Environmental Gene Regulatory Influence Networks (EGRINs) coordinate the timing and rate of gene expression in response to environmental and developmental signals. EGRINs encompass many layers of regulation, which culminate in changes in the level of accumulated transcripts. Here we infer EGRINs for the response of five tropical Asian rice cultivars to high temperatures, water deficit, and agricultural field conditions, by systematically integrating time series transcriptome data (720 RNA-seq libraries), patterns of nucleosome-free chromatin (18 ATAC-seq libraries), and the occurrence of known cis-regulatory elements. First, we identify 5,447 putative target genes for 445 transcription factors (TFs) by connecting TFs with genes with known cis-regulatory motifs in nucleosome-free chromatin regions proximal to transcriptional start sites (TSS) of genes. We then use network component analysis to estimate the regulatory activity for these TFs from the expression of these putative target genes. Finally, we inferred an EGRIN using the estimated TFA as the regulator. The EGRIN included regulatory interactions between 4,052 target genes regulated by 113 TFs. We resolved distinct regulatory roles for members of a large TF family, including a putative regulatory connection between abiotic stress and the circadian clock, as well as specific regulatory functions for TFs in the drought response. TFA estimation using network component analysis is an effective way of incorporating multiple genome-scale measurements into network inference and that supplementing data from controlled experimental conditions with data from outdoor field conditions increases the resolution for EGRIN inference.
PrometheusWiki: online protocols gaining momentum
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/FPV38N11_ED
Seed mass and elevation explain variation in seed longevity of Australian alpine species
Publisher: Cambridge University Press (CUP)
Date: 15-03-2018
DOI: 10.1017/S0960258518000090
Abstract: Conserving alpine ecosystems and the plant communities they contain using ex situ conservation requires an understanding of seed longevity. Knowledge of seed longevity may determine the effectiveness of ex situ seed banking for alpine plant conservation, and may provide insight into plant recruitment in situ . We sought to determine the influence of elevation and climatic variables, as well as plant and seed traits, on the seed longevity of 57 species inhabiting a unique biome, (sub-)alpine regions of mainland Australia. Seed longevity was estimated using controlled accelerated ageing tests to determine the time taken for seed viability to fall by 50%. We found that, across the study species, like alpine seeds elsewhere in the world, Australian alpine seeds are relatively short-lived and overall shorter-lived than Australian plants in general. Seed mass and elevation explained most of the variation in seed longevity among the Australian alpine species considered. Species with larger seed mass, and collections made at higher elevations, were found to have relatively short-lived seeds. Phylogeny, however, explained very little of the variation in longevity. Our results suggest that viability testing for Australian alpine seeds in ex situ seed banks should be conducted with shorter intervals than for the non-alpine flora. This study highlights how seed longevity in the Australian Alps is not dictated primarily by evolutionary lineage but rather by a complex combination of environmental variables and intrinsic seed characteristics. Potential implications for conservation ex situ and in situ in the context of climate change are discussed.
Evidence of population variation in drought tolerance during seed germination in four Banksia (Proteaceae) species from Western Australia
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/BT14132
Abstract: Given the predicted changes in rainfall patterns for many Mediterranean climate regions, identifying seed tolerance to moisture stress in the earliest phase of plant development is an important consideration for species conservation, management and restoration. Here, we used polyethylene glycol (PEG 8000) to induce plant water deficit similar to drought stress in a field situation. Seeds of four Western Australia Banksia R.Br. (Proteaceae) species were incubated at seven levels of moisture potential (0 to −1.5 MPa) and three constant temperatures (10°C, 15°C and 20°C). In the absence of moisture stress, germination was uniformly high, but increasing drought stress led to reduced and delayed germination in all species. Overall, the threshold moisture potential value for a significant decline, and delay, in germination was –0.25 MPa. Results suggested that one species (B. coccinea) is likely to be most vulnerable to germination failure under predicted changes in rainfall patterns, whereas another (B. media) is likely to be less vulnerable. There was significant variation in population response to drought stress. However, this variation could not be explained by rainfall across species distributions. We discuss the PEG approach for assessing seed sensitivity to moisture stress, particularly in the context of shifting rainfall under climate change.
Temperature variability drives within-species variation in germination strategy and establishment characteristics of an alpine herb
Publisher: Springer Science and Business Media LLC
Date: 02-01-2019
DOI: 10.1007/S00442-018-04328-2
Abstract: Plant establishment and subsequent persistence are strongly influenced by germination strategy, especially in temporally and spatially heterogeneous environments. Germination strategy determines the plant's ability to synchronise germination timing and seedling emergence to a favourable growing season and thus variation in germination strategy within species may be key to persistence under more extreme and variable future climates. However, the determinants of variation in germination strategy are not well resolved. To understand the variation of germination strategy and the climate drivers, we assessed seed traits, germination patterns, and seedling establishment traits of Oreomyrrhis eriopoda from 29 populations across its range. Germination patterns were then analysed against climate data to determine the strongest climate correlates influencing the germination strategy. Oreomyrrhis eriopoda exhibits a striking range of germination strategies among populations: varying from immediate to staggered, postponed, and postponed-deep. Seeds from regions with lower temperature variability were more likely to exhibit an immediate germination strategy however, those patterns depended on the timescale of climatic assessment. In addition, we show that these strategy differences extend to seedling establishment traits: autumn seedlings (from populations with an immediate or staggered germination strategy) exhibited a higher leaf production rate than spring seedlings (of staggered or postponed strategy). Our results demonstrate not only substantial within-species variation in germination strategy across the species distribution range, but also that this variation correlates with environmental drivers. Given that these differences also extend to establishment traits, they may reflect a critical mechanism for persistence in changing climate.
Plant isolation reduces outcross pollen receipt in a partially self-compatible herb
Publisher: Wiley
Date: 20-10-2004
Crown structure and vertical foliage distribution in 4-year-old plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana
Publisher: Springer Science and Business Media LLC
Date: 23-11-2013
Foundations for the future: A long-term plan for Australian ecosystem science
Publisher: Wiley
Date: 09-09-2014
DOI: 10.1111/AEC.12188
SIGNIFICANT PHOROPHYTE (SUBSTRATE) BIAS IS NOT EXPLAINED BY FITNESS BENEFITS IN THREE EPIPHYTIC ORCHID SPECIES
Publisher: Wiley
Date: 02-2011
DOI: 10.3732/AJB.1000241
Abstract: Epiphytes rely on their phorophyte (host substrate) for support epiphytic orchids also rely on mycorrhizal fungi for germination. Previous studies have proposed a degree of specificity in both interactions. Epiphytic orchids therefore provide an interesting system in which to examine multispecies interactions and the evolution of specialization. We examined the potential and actual distributions of three co-occurring, related epiphytic orchid species: Sarcochilus hillii, Plectorrhiza tridentata, and Sarcochilus parviflorus on phorophytes in Australia's temperate dry rainforests. These three small epiphytic orchid species were all biased toward certain woody plant species, in particular, the tree Backhousia myrtifolia, though the extent of specificity varied. Biases toward the most common phorophyte species were not explained by increases in adult orchid fitness, nor did probability of flowering increase on B. myrtifolia. Indeed, in iduals on this woody phorophyte tended to have fewer inflorescences than those on other woody phorophytes. Only S. hillii benefited from establishment on B. myrtifolia it had more leaves on this phorophyte than on others. In many cases what appear to be simple interactions between two species may be mediated by more complex symbioses. For this system, we propose that the cause for bias in orchid distribution occurs much earlier in an orchid's life and may be due to a bias of their mycorrhizal fungi for the dominant orchid phorophytes.
Delivery of Acetate to the Peripheral Blood after Consumption of Foods High in Short‐Chain Fatty Acids
Publisher: Wiley
Date: 22-01-2021
Abstract: To promote local and systemic benefits of short‐chain fatty acids (SCFA), methods of increasing their delivery to the gastrointestinal tract are needed. SCFA in foods and beverages represents a poorly characterized source. Main aims of this study are: 1) quantify SCFA in commonly consumed foods and beverages, and 2) explore the pharmacokinetics of consuming oral SCFA from dietary sources. Gas‐chromatography coupled to flame ionization detection is used measure SCFA in 38 commonly consumed foods and beverages. Acetate is the most abundant SCFA detected, with kombucha and vinegar found to provide mg of acetate per serve. An acute pharmacokinetic study is conducted in 10 participants. Acetate is stable across the 2‐h s ling period after consumption of a control drink, with consumption of a vinegar drink containing 25 mmol acetate significantly increasing plasma acetate concentration after 60 min and increasing acetate delivery to the blood upon assessment of the area under the pharmacokinetic curve. Fermented foods and beverages are a natural source of dietary SCFA that acutely deliver SCFA to the blood. If systemic delivery is needed for immunological and metabolic effects to occur, these may be achieved if delivered over a longer period of time.
Effect of soil biota on growth and allocation by Eucalyptus microcarpa
Publisher: Springer Science and Business Media LLC
Date: 15-02-2008
Photosynthetic response to green crown pruning in young plantation-grown Eucalyptus pilularis and E-cloeziana
Publisher: Elsevier BV
Date: 06-2008
How to analyse plant phenotypic plasticity in response to a changing climate
Publisher: Wiley
Date: 25-01-2019
DOI: 10.1111/NPH.15656
Abstract: Contents Summary 1235 I. Introduction 1235 II. The many shapes of phenotypic plasticity 1236 III. Random regression mixed model framework 1237 IV. Conclusions 1240 Acknowledgements 1240 References 1240 SUMMARY: Plant biology is experiencing a renewed interest in the mechanistic underpinnings and evolution of phenotypic plasticity that calls for a re-evaluation of how we analyse phenotypic responses to a rapidly changing climate. We suggest that dissecting plant plasticity in response to increasing temperature needs an approach that can represent plasticity over multiple environments, and considers both population-level responses and the variation between genotypes in their response. Here, we outline how a random regression mixed model framework can be applied to plastic traits that show linear or nonlinear responses to temperature. Random regressions provide a powerful and efficient means of characterising plasticity and its variation. Although they have been used widely in other fields, they have only recently been implemented in plant evolutionary ecology. We outline their structure and provide an ex le tutorial of their implementation.
The plant detectives: innovative undergraduate teaching to inspire the next generation of plant biologists
Publisher: Frontiers Media SA
Date: 15-09-2015
Sexes show contrasting patterns of leaf and crown carbon gain in a dioecious rainforest shrub
Publisher: Wiley
Date: 03-2003
DOI: 10.3732/AJB.90.3.347
Abstract: The sexes of dioecious species may differ in a range of vegetative and reproductive traits as well as in physiological traits. In Siparuna grandiflora, a Neotropical dioecious shrub, we examined differences in leaf-level photosynthesis of different classes of leaf age and, using simulation models, explored whether differences in leaf-level carbon gain led to sex differences in whole-plant daily carbon gain. Male plants had higher photosynthetic capacity at the leaf level. As leaves of both sexes aged their photosynthetic capacity and specific leaf area declined as expected. Simulations of daily carbon gain using the architecturally explicit model Y-Plant and a non-architectural model incorporating a wide range of realistic light environments revealed that the difference in leaf-level photosynthetic capacity did not translate into greater crown-level carbon gain for males. Rather, differences in patterns of allocation to leaf area allow females to achieve higher crown-level carbon gain. The results demonstrate that sex differences at the leaf level do not necessarily predict patterns at the whole-plant level.
Predicting effects of warming requires a whole-of-life cycle perspective: a case study in the alpine herb Oreomyrrhis eriopoda
Publisher: Oxford University Press (OUP)
Date: 2021
Abstract: Global warming is affecting plant phenology, growth and reproduction in complex ways and is particularly apparent in vulnerable alpine environments. Warming affects reproductive and vegetative traits, as well as phenology, but seldom do studies assess these traits in concert and across the whole of a plant’s life cycle, particularly in wild species. Thus, it is difficult to extrapolate from such effects to predictions about the persistence of species or their conservation and management. We assessed trait variation in response to warming in Oreomyrrhis eriopoda, an Australian native montane herb, in which populations vary in germination strategy (degree of dormancy) and growth characteristics as a function of ecological factors. Warming accelerated growth in the early stages of development, particularly for populations with non-dormant seed. The differences in growth disappeared at the transition to reproduction, when an accelerating effect on phenology emerged, to varying degrees depending on germination strategy. Overall, warming reduced flower and seed production and increased mortality, indicating a reduction in reproductive opportunities, particularly for populations with dormant seed. Developmental condition affected germination strategy of the next generation seed, leading to increased degree of dormancy and slowed germination rate. But there were no whole-scale shifts in strategy or total germination percent. Following through the life cycle reveals that warming will have some potentially positive effects (early growth rates) and some negative effects (reduced reproductive output). Ultimately, warming impacts will depend on how those effects play out in the field: early establishment and an accelerated trajectory to seed maturity may offset the tradeoff with overall seed production. Small differences among germination strategies likewise may cascade to larger effects, with important implications for persistence of species in the alpine landscape. Thus, to understand and manage the response of wild species to warming takes a whole-of-life perspective and attention to ecologically significant patterns of within-species variation.
Rooting Volume, Nutrient Availability, and CO 2 -Induced Growth Enhancements in Temperate Forest Tree Seedlings
Publisher: Wiley
Date: 05-1996
DOI: 10.2307/2269396
Soil warming increases plant species richness but decreases germination from the alpine soil seed bank
Publisher: Wiley
Date: 07-02-2013
DOI: 10.1111/GCB.12135
Abstract: Global warming is occurring more rapidly above the treeline than at lower elevations and alpine areas are predicted to experience above average warming in the future. Temperature is a primary factor in stimulating seed germination and regulating changes in seed dormancy status. Thus, plant regeneration from seed will be crucial to the persistence, migration and post disturbance recruitment of alpine plants in future climates. Here, we present the first assessment of the impact of soil warming on germination from the persistent alpine soil seed bank. Contrary to expectations, soil warming lead to reduced overall germination from the soil seed bank. However, germination response to soil temperature was species specific such that total species richness actually increased by nine with soil warming. We further explored the system by assessing the prevalence of seed dormancy and germination response to soil disturbance, the frequency of which is predicted to increase under climate change. Seeds of a significant proportion of species demonstrated physiological dormancy mechanisms and germination of several species appeared to be intrinsically linked to soil disturbance. In addition, we found no evidence of subalpine species and little evidence of exotic weed species in the soil, suggesting that the soil seed bank will not facilitate their invasion of the alpine zone. In conclusion, changes in recruitment via the alpine soil seed bank can be expected under climate change, as a result of altered dormancy alleviation and germination cues. Furthermore, the alpine soil seed bank, and the species richness therein, has the potential to help maintain local species ersity, support species range shift and moderate species dominance. Implications for alpine management and areas for further study are also discussed.
The presence of nodules on legume root systems can alter phenotypic plasticity in response to internal nitrogen independent of nitrogen fixation
Publisher: Wiley
Date: 21-01-2016
DOI: 10.1111/PCE.12672
Abstract: All higher plants show developmental plasticity in response to the availability of nitrogen (N) in the soil. In legumes, N starvation causes the formation of root nodules, where symbiotic rhizobacteria fix atmospheric N2 for the host in exchange for fixed carbon (C) from the shoot. Here, we tested whether plastic responses to internal [N] of legumes are altered by their symbionts. Glasshouse experiments compared root phenotypes of three legumes, Medicago truncatula, Medicago sativa and Trifolium subterraneum, inoculated with their compatible symbiont partners and grown under four nitrate levels. In addition, six strains of rhizobia, differing in their ability to fix N2 in M. truncatula, were compared to test if plastic responses to internal [N] were dependent on the rhizobia or N2 -fixing capability of the nodules. We found that the presence of rhizobia affected phenotypic plasticity of the legumes to internal [N], particularly in root length and root mass ratio (RMR), in a plant species-dependent way. While root length responses of M. truncatula to internal [N] were dependent on the ability of rhizobial symbionts to fix N2 , RMR response to internal [N] was dependent only on initiation of nodules, irrespective of N2 -fixing ability of the rhizobia strains.
Phenotypic plasticity and water availability: responses of alpine herb species along an elevation gradient
Publisher: Springer Science and Business Media LLC
Date: 15-09-2017
Low solvent, low temperature method for extracting biodiesel lipids from concentrated microalgal biomass
Publisher: Elsevier BV
Date: 11-2013
Trees tolerate an extreme heatwave via sustained transpirational cooling and increased leaf thermal tolerance
Publisher: Wiley
Date: 02-02-2018
DOI: 10.1111/GCB.14037
Abstract: Heatwaves are likely to increase in frequency and intensity with climate change, which may impair tree function and forest C uptake. However, we have little information regarding the impact of extreme heatwaves on the physiological performance of large trees in the field. Here, we grew Eucalyptus parramattensis trees for 1 year with experimental warming (+3°C) in a field setting, until they were greater than 6 m tall. We withheld irrigation for 1 month to dry the surface soils and then implemented an extreme heatwave treatment of 4 consecutive days with air temperatures exceeding 43°C, while monitoring whole-canopy exchange of CO
IDEAcology: An interface to streamline and facilitate efficient, rigorous expert elicitation in ecology
Publisher: Wiley
Date: 13-06-2023
Abstract: Here, we demonstrate how IDEAcology aids in preparing for and implementing a structured expert elicitation using the IDEA protocol, an iterative quantitative expert elicitation framework. Expert judgement is used to inform decision‐making on environmental assessment and management when imminent decisions are required, and quantitative data are absent or uninformative. Structured elicitation protocols can help improve the final judgements derived from experts, but they can also be administratively heavy and time‐consuming, requiring manual collation of experts' estimates and rationales, construction and dissemination of summary plots for discussion and collating final estimates post‐discussion. These challenges highlight the need for a centralised portal that enables synchronous access by all contributors, real‐time structured facilitation of discussion, whether in person or online, and streamlined data management. To meet this need, we developed the IDEAcology interface ( www.ideacology.com ) to support data collation, summary, interactions and ultimately the deployment of structured expert elicitation using the IDEA protocol. The IDEAcology interface is designed to be a central portal for scientists and practitioners to easily implement structured expert elicitation projects, while also facilitating data management by providing a reliable and efficient way for elicitation managers to design and run an elicitation, and for experts to input, visualise and cross‐examine estimates. The key advantages that IDEAcology provides include an easy‐to‐use interface with synchronous access to a single platform, reducing logistic difficulties, facilitating transparent discussion, improving the accuracy of estimates, enabling fast and efficient reporting by providing analysis‐ready data outputs and lastly, flexibility in the types of elicitation questions that can be accommodated in the interface.
Variation in plant functional traits across and within four species of Western Australian Banksia (Proteaceae) along a natural climate gradient
Publisher: Wiley
Date: 02-08-2016
DOI: 10.1111/AEC.12381
Landscape genomic prediction for restoration of a Eucalyptus foundation species under climate change
Publisher: eLife Sciences Publications, Ltd
Date: 24-04-2018
DOI: 10.7554/ELIFE.31835
Abstract: As species face rapid environmental change, we can build resilient populations through restoration projects that incorporate predicted future climates into seed sourcing decisions. Eucalyptus melliodora is a foundation species of a critically endangered community in Australia that is a target for restoration. We examined genomic and phenotypic variation to make empirical based recommendations for seed sourcing. We examined isolation by distance and isolation by environment, determining high levels of gene flow extending for 500 km and correlations with climate and soil variables. Growth experiments revealed extensive phenotypic variation both within and among s ling sites, but no site-specific differentiation in phenotypic plasticity. Model predictions suggest that seed can be sourced broadly across the landscape, providing le ersity for adaptation to environmental change. Application of our landscape genomic model to E. melliodora restoration projects can identify genomic variation suitable for predicted future climates, thereby increasing the long term probability of successful restoration.
A high-throughput method for measuring critical thermal limits of leaves by chlorophyll imaging fluorescence
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/FP20344
Abstract: Plant thermal tolerance is a crucial research area as the climate warms and extreme weather events become more frequent. Leaves exposed to temperature extremes have inhibited photosynthesis and will accumulate damage to PSII if tolerance thresholds are exceeded. Temperature-dependent changes in basal chlorophyll fluorescence (T-F0) can be used to identify the critical temperature at which PSII is inhibited. We developed and tested a high-throughput method for measuring the critical temperatures for PSII at low (CTMIN) and high (CTMAX) temperatures using a Maxi-Imaging fluorimeter and a thermoelectric Peltier plate heating/cooling system. We examined how experimental conditions of wet vs dry surfaces for leaves and heating/cooling rate, affect CTMIN and CTMAX across four species. CTMAX estimates were not different whether measured on wet or dry surfaces, but leaves were apparently less cold tolerant when on wet surfaces. Heating/cooling rate had a strong effect on both CTMAX and CTMIN that was species-specific. We discuss potential mechanisms for these results and recommend settings for researchers to use when measuring T-F0. The approach that we demonstrated here allows the high-throughput measurement of a valuable ecophysiological parameter that estimates the critical temperature thresholds of leaf photosynthetic performance in response to thermal extremes.
Facilitated transport behavior of humidified gases through thin-film composite polyamide membranes for carbon dioxide capture
Publisher: Elsevier BV
Date: 02-2013
An innovative approach to using an intensive field course to build scientific and professional skills
Publisher: Cold Spring Harbor Laboratory
Date: 08-12-2021
DOI: 10.1101/2021.12.06.471369
Abstract: This paper reports on the design and evaluation of Field Studies in Functional Ecology (FSFE), a two-week intensive residential field course that enables students to master core content in functional ecology alongside skills that facilitate their transition from ‘student’ to ‘scientist’. This paper provides an overview of the course structure, showing how the constituent elements have been designed and refined over successive iterations of the course. We detail how FSFE students: 1. Work closely with discipline specialists to develop a small group project that tests an hypothesis to answer a genuine scientific question in the field 2. Learn critical skills of data management and communication and 3. Analyse, interpret and present their results in the format of a scientific symposium. This process is repeated in an iterative ‘cognitive apprenticeship’ model, supported by a series of workshops that name and explicitly instruct the students in ‘hard’ and ‘soft’ skills critical relevant for research and other careers. FSFE students develop a coherent and nuanced understanding of how to approach and execute ecological studies. The sophisticated knowledge and ecological research skills that they develop during the course is demonstrated through high quality presentations and peer-reviewed publications in an open-access, student-led journal. We outline our course structure and evaluate its efficacy to show how this novel combination of field course elements allows students to gain maximum value from their educational journey, and to develop cognitive, affective and reflective tools to help apply their skills as scientists.
Climate warming delays and decreases seedling emergence in a Mediterranean ecosystem
Publisher: Wiley
Date: 07-2015
DOI: 10.1111/OIK.01359
Experimental and theoretical studies on the movements of two bubbles in an acoustic standing wave field
Publisher: American Chemical Society (ACS)
Date: 07-10-2013
DOI: 10.1021/JP404886H
Abstract: When subjected to an ultrasonic standing-wave field, cavitation bubbles smaller than the resonance size migrate to the pressure antinodes. As bubbles approach the antinode, they also move toward each other and either form a cluster or coalesce. In this study, the translational trajectory of two bubbles moving toward each other in an ultrasonic standing wave at 22.4 kHz was observed using an imaging system with a high-speed video camera. This allowed the speed of the approaching bubbles to be measured for much closer distances than those reported in the prior literature. The trajectory of two approaching bubbles was modeled using coupled equations of radial and translational motions, showing similar trends with the experimental results. We also indirectly measured the secondary Bjerknes force by monitoring the acceleration when bubbles are close to each other under different acoustic pressure litudes. Bubbles begin to accelerate toward each other as the distance between them gets shorter, and this acceleration increases with increasing acoustic pressure. The current study provides experimental data that validates the theory on the movement of bubbles and forces acting between them in an acoustic field that will be useful in understanding bubble coalescence in an acoustic field.
Polyploidy affects the seed, dormancy and seedling characteristics of a perennial grass, conferring an advantage in stressful climates
Publisher: Wiley
Date: 10-03-2020
DOI: 10.1111/PLB.13094
Nitrogen in cell walls of sclerophyllous leaves accounts for little of the variation in photosynthetic nitrogen-use efficiency
Publisher: Wiley
Date: 27-01-2009
DOI: 10.1111/J.1365-3040.2008.01918.X
Abstract: Photosynthetic rate per unit nitrogen generally declines as leaf mass per unit area (LMA) increases. To determine how much of this decline was associated with allocating a greater proportion of leaf nitrogen into cell wall material, we compared two groups of plants. The first group consisted of two species from each of eight genera, all of which were perennial evergreens growing in the Australian National Botanic Gardens (ANBG). The second group consisted of seven Eucalyptus species growing in a greenhouse. The percentage of leaf biomass in cell walls was independent of variation in LMA within any genus, but varied from 25 to 65% between genera. The nitrogen concentration of cell wall material was 0.4 times leaf nitrogen concentration for all species apart from Eucalyptus, which was 0.6 times leaf nitrogen concentration. Between 10 and 30% of leaf nitrogen was recovered in the cell wall fraction, but this was independent of LMA. No trade-off was observed between nitrogen associated with cell walls and the nitrogen allocated to ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco). Variation in photosynthetic rate per unit nitrogen could not be explained by variation in cell wall nitrogen.
The seed germination spectrum of alpine plants: a global meta‐analysis
Publisher: Wiley
Date: 24-12-2020
DOI: 10.1111/NPH.17086
Geographic range size, seedling ecophysiology and phenotypic plasticity in Australian Acacia species
Publisher: Wiley
Date: 20-01-2005
Repeated extreme heatwaves result in higher leaf thermal tolerances and greater safety margins
Publisher: Wiley
Date: 30-08-2021
DOI: 10.1111/NPH.17640
Abstract: The frequency and severity of heatwave events are increasing, exposing species to conditions beyond their physiological limits. Species respond to heatwaves in different ways, however it remains unclear if plants have the adaptive capacity to successfully respond to hotter and more frequent heatwaves. We exposed eight tree populations from two climate regions grown under cool and warm temperatures to repeated heatwave events of moderate (40°C) and extreme (46°C) severity to assess adaptive capacity to heatwaves. Leaf damage and maximum quantum efficiency of photosystem II ( F v / F m ) were significantly impacted by heatwave severity and growth temperatures, respectively populations from a warm‐origin avoided damage under moderate heatwaves compared to those from a cool‐origin, indicating a degree of local adaptation. We found that plasticity to heatwave severity and repeated heatwaves contributed to enhanced thermal tolerance and lower leaf temperatures , leading to greater thermal safety margins (thermal tolerance minus leaf temperature) in a second heatwave. Notably, while we show that adaptation and physiological plasticity are important factors affecting plant adaptive capacity to thermal stress, plasticity of thermal tolerances and thermal safety margins provides the opportunity for trees to persist among fluctuating heatwave exposures.
A research agenda for seed‐trait functional ecology
Publisher: Wiley
Date: 25-10-2018
DOI: 10.1111/NPH.15502
Abstract: Trait-based approaches have improved our understanding of plant evolution, community assembly and ecosystem functioning. A major challenge for the upcoming decades is to understand the functions and evolution of early life-history traits, across levels of organization and ecological strategies. Although a variety of seed traits are critical for dispersal, persistence, germination timing and seedling establishment, only seed mass has been considered systematically. Here we suggest broadening the range of morphological, physiological and biochemical seed traits to add new understanding on plant niches, population dynamics and community assembly. The ersity of seed traits and functions provides an important challenge that will require international collaboration in three areas of research. First, we present a conceptual framework for a seed ecological spectrum that builds upon current understanding of plant niches. We then lay the foundation for a seed-trait functional network, the establishment of which will underpin and facilitate trait-based inferences. Finally, we anticipate novel insights and challenges associated with incorporating erse seed traits into predictive evolutionary ecology, community ecology and applied ecology. If the community invests in standardized seed-trait collection and the implementation of rigorous databases, major strides can be made at this exciting frontier of functional ecology.
Plant phenotypic plasticity in a changing climate
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.TPLANTS.2010.09.008
Abstract: Climate change is altering the availability of resources and the conditions that are crucial to plant performance. One way plants will respond to these changes is through environmentally induced shifts in phenotype (phenotypic plasticity). Understanding plastic responses is crucial for predicting and managing the effects of climate change on native species as well as crop plants. Here, we provide a toolbox with definitions of key theoretical elements and a synthesis of the current understanding of the molecular and genetic mechanisms underlying plasticity relevant to climate change. By bringing ecological, evolutionary, physiological and molecular perspectives together, we hope to provide clear directives for future research and stimulate cross-disciplinary dialogue on the relevance of phenotypic plasticity under climate change.
Sexually dimorphic growth in the dioecious tropical shrub, Siparuna grandiflora
Publisher: Wiley
Date: 06-1999
Convective transport of boron through a brackish water reverse osmosis membrane
Publisher: Elsevier BV
Date: 10-2013
Transcriptional acclimation to warming temperatures of the Australian alpine herbWahlenbergia ceracea
Publisher: Cold Spring Harbor Laboratory
Date: 28-09-2023
Patterns of genotypic variation and phenotypic plasticity of light response in two tropical Piper (Piperaceae) species
Publisher: Wiley
Date: 11-1997
DOI: 10.2307/2446616
A unique web resource for physiology, ecology and the environmental sciences: PrometheusWiki
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/FP10097
Abstract: PROtocols, METHods, Explanations and Updated Standards Wiki (PrometheusWiki, www.publish.csiro.au rometheuswiki/) is a new open access, fully searchable web resource that contains protocols and methods for plant physiology, ecology and environmental sciences. Contributions can be uploaded by anyone in the community, with attributed authorship, and are open for wiki-style comment. This resource allows the gathering in one place of methods, links to published methods and detailed protocols used by leading laboratories around the world, with annotation. As a web resource, PrometheusWiki is continually evolving and updatable, easily and rapidly searchable and highly accessible. It will also enhance communication, allowing multimedia description of protocols and techniques, with spreadsheet tools, slide shows and video files easily integrated into the text. This resource is anticipated to lead to strong benefits in standardising methods, improving access to training for students and professionals, promoting collaborations and expanding the cutting edge of research.
Predicting species and community responses to global change using structured expert judgement: An Australian mountain ecosystems case study
Publisher: Wiley
Date: 02-07-2021
DOI: 10.1111/GCB.15750
Abstract: Conservation managers are under increasing pressure to make decisions about the allocation of finite resources to protect bio ersity under a changing climate. However, the impacts of climate and global change drivers on species are outpacing our capacity to collect the empirical data necessary to inform these decisions. This is particularly the case in the Australian Alps which have already undergone recent changes in climate and experienced more frequent large‐scale bushfires. In lieu of empirical data, we use a structured expert elicitation method (the IDEA protocol) to estimate the change in abundance and distribution of nine vegetation groups and 89 Australian alpine and subalpine species by the year 2050. Experts predicted that most alpine vegetation communities would decline in extent by 2050 only woodlands and heathlands are predicted to increase in extent. Predicted species‐level responses for alpine plants and animals were highly variable and uncertain. In general, alpine plants spanned the range of possible responses, with some expected to increase, decrease or not change in cover. By contrast, almost all animal species are predicted to decline or not change in abundance or elevation range more species with water‐centric life‐cycles are expected to decline in abundance than other species. While long‐term ecological data will always be the gold standard for informing the future of bio ersity, the method and outcomes outlined here provide a pragmatic and coherent basis upon which to start informing conservation policy and management in the face of rapid change and a paucity of data.
Aboveground interactions and productivity in mixed-species plantations of Acacia mearnsii and Eucalyptus globulus
Publisher: Canadian Science Publishing
Date: 03-2004
DOI: 10.1139/X03-243
Abstract: This study compared productivity in mixed-species plantations of Eucalyptus globulus ssp. pseudoglobulus (Naudin ex Maiden) Kirkpatr. and Acacia mearnsii de Wild with pure stands of each species and investigated how this might be explained by canopy stratification between species and changes in leaf characteristics of eucalypts. Investigations were carried out at a trial using the replacement series design, which consisted of the following combinations: 100% eucalypts (100%E), 75% eucalypts + 25% acacia (75%E:25%A), 50% eucalypts + 50% acacia (50%E:50%A), 25% eucalypts + 75% acacia (25%E:75%A), and 100% acacia (100%A). At 9.5 years, stem volume and biomass were highest in 50%E:50%A treatments. Canopy stratification occurred in all mixtures, with acacias in the lower and eucalypts in the upper canopy stratum. This and the increasing canopy light interception with increasing proportion of acacia in the mixture indicated that A. mearnsii is substantially more shade tolerant than E. globulus. Midcanopy foliage of E. globulus in the 50%E:50%A mixture had higher foliage nitrogen (N) but lower phosphorus (P) concentrations and lower light-saturated net photosynthesis rates (A max ) than those in the 100%E treatment. In addition, similar relationships between eucalypt crown volume and stem biomass across treatments indicated that eucalypt crowns were not more efficient in mixture. Our study indicates that the productivity gains in these mixtures may be partially attributable to aboveground niche separation between species.
Spatial patterning of pigmentation in evergreen leaves in response to freezing stress
Publisher: Wiley
Date: 20-10-2003
Formation of a thick aromatic polyamide membrane by interfacial polymerisation
Publisher: Elsevier BV
Date: 02-2013
Adaptive plasticity and epigenetic variation in response to warming in an Alpine plant
Publisher: Wiley
Date: 13-01-2015
DOI: 10.1002/ECE3.1329
Leaf shape linked to photosynthetic rates and temperature optima in South African Pelargonium species
Publisher: Springer Science and Business Media LLC
Date: 18-10-2008
DOI: 10.1007/S00442-007-0865-1
Abstract: The thermal response of gas exchange varies among plant species and with growth conditions. Plants from hot dry climates generally reach maximal photosynthetic rates at higher temperatures than species from temperate climates. Likewise, species in these environments are predicted to have small leaves with more-dissected shapes. We compared eight species of Pelargonium (Geraniaceae) selected as phylogenetically independent contrasts on leaf shape to determine whether: (1) the species showed plasticity in thermal response of gas exchange when grown under different water and temperature regimes, (2) there were differences among more- and less-dissected leafed species in trait means or plasticity, and (3) whether climatic variables were correlated with the responses. We found that a higher growth temperature led to higher optimal photosynthetic temperatures, at a cost to photosynthetic capacity. Optimal temperatures for photosynthesis were greater than the highest growth temperature regime. Stomatal conductance responded to growth water regime but not growth temperature, whereas transpiration increased and water use efficiency (WUE) decreased at the higher growth temperature. Strikingly, species with more-dissected leaves had higher rates of carbon gain and water loss for a given growth condition than those with less-dissected leaves. Species from lower latitudes and lower rainfall tended to have higher photosynthetic maxima and conductance, but leaf dissection did not correlate with climatic variables. Our results suggest that the combination of dissected leaves, higher photosynthetic rates, and relatively low WUE may have evolved as a strategy to optimize water delivery and carbon gain during short-lived periods of high soil moisture. Higher thermal optima, in conjunction with leaf dissection, may reflect selection pressure to protect photosynthetic machinery against excessive leaf temperatures when stomata close in response to water stress.
The evolution and functional significance of leaf shape in the angiosperms
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/FP11057
Abstract: Angiosperm leaves manifest a remarkable ersity of shapes that range from developmental sequences within a shoot and within crown response to microenvironment to variation among species within and between communities and among orders or families. It is generally assumed that because photosynthetic leaves are critical to plant growth and survival, variation in their shape reflects natural selection operating on function. Several non-mutually exclusive theories have been proposed to explain leaf shape ersity. These include: thermoregulation of leaves especially in arid and hot environments, hydraulic constraints, patterns of leaf expansion in deciduous species, biomechanical constraints, adaptations to avoid herbivory, adaptations to optimise light interception and even that leaf shape variation is a response to selection on flower form. However, the relative importance, or likelihood, of each of these factors is unclear. Here we review the evolutionary context of leaf shape ersification, discuss the proximal mechanisms that generate the ersity in extant systems, and consider the evidence for each the above hypotheses in the context of the functional significance of leaf shape. The synthesis of these broad ranging areas helps to identify points of conceptual convergence for ongoing discussion and integrated directions for future research.
Reliability of pathophysiological markers reflective of exercise-induced gastrointestinal syndrome (EIGS) in response to 2-h high-intensity interval exercise: A comprehensive methodological efficacy exploration
Publisher: Frontiers Media SA
Date: 21-02-2023
DOI: 10.3389/FPHYS.2023.1063335
Abstract: The study aimed to determine the test-retest reliability of exercise-induced gastrointestinal syndrome (EIGS) biomarkers, and assess the association of pre-exercise short chain fatty acid (SCFA) concentration with these biomarkers in response to prolonged strenuous exercise. Thirty-four participants completed 2 h of high-intensity interval training (HIIT) on two separate occasions with at least 5-days washout. Blood s les were collected pre- and post-exercise, and analysed for biomarkers associated with EIGS [i.e., cortisol, intestinal fatty-acid binding protein (I-FABP), sCD14, lipopolysaccharide binding protein (LBP), leukocyte counts, in-vitro neutrophil function, and systemic inflammatory cytokine profile]. Fecal s les were collected pre-exercise on both occasions. In plasma and fecal s les, bacterial DNA concentration was determined by fluorometer quantification, microbial taxonomy by 16S rRNA licon sequencing, and SCFA concentration by gas-chromatography. In response to exercise, 2 h of HIIT modestly perturbed biomarkers indicative of EIGS, including inducing bacteremia (i.e., quantity and ersity). Reliability analysis using comparative tests, Cohen’s d , two-tailed correlation, and intraclass correlation coefficient (ICC) of resting biomarkers presented good-to-excellent for IL-1ra ( r = 0.710, ICC = 0.92), IL-10 ( r = 0.665, ICC = 0.73), cortisol ( r = 0.870, ICC = 0.87), and LBP ( r = 0.813, ICC = 0.76) moderate for total ( r = 0.839, ICC = 0.44) and per cell ( r = 0.749, ICC = 0.54) bacterially-stimulated elastase release, IL-1β ( r = 0.625, ICC = 0.64), TNF-α ( r = 0.523, ICC = 0.56), I-FABP ( r = 0.411, ICC = 0.21), and sCD14 ( r = 0.409, ICC = 0.38), plus fecal bacterial α- ersity and poor for leukocyte ( r = 0.327, ICC = 0.33) and neutrophil ( r = 0.352, ICC = 0.32) counts. In addition, a medium negative correlation was observed between plasma butyrate and I-FABP ( r = −0.390). The current data suggest a suite of biomarkers should be used to determine the incidence and severity of EIGS. Moreover, determination of plasma and/or fecal SCFA may provide some insight into the mechanistic aspects of EIGS instigation and magnitude in response to exercise.
Dynamics of stomatal water relations following leaf excision
Publisher: Wiley
Date: 16-03-2006
DOI: 10.1111/J.1365-3040.2005.01491.X
Abstract: We examined the stomatal response to leaf excision in an evergreen woody shrub, Photinia x fraseri, using a novel combination of gas exchange, traditional water relations and modelling. Plants were kept outdoors in mild winter conditions (average daily temperature range: -1 to 12 degrees C) before being transferred to a glasshouse (temperature range: 20-30 degrees C) and allowed to acclimate for different periods before experiments. 'Glasshouse plants' were acclimated for at least 9 d, and 'outdoor plants' were acclimated for fewer than 3 d before laboratory gas exchange experiments. The transient stomatal opening response to leaf excision was roughly twice as long in outdoor plants as in glasshouse plants. To elucidate the reason for this difference, we inferred variables of stomatal water relations (epidermal and guard cell turgor pressures and guard cell osmotic pressure: Pe, Pg and pi g, respectively) from stomatal conductance (gs) and bulk leaf water potential (psi l), using a hydromechanical model of gs. psi l was calculated from cumulative post-excision transpirational water loss using empirical relationships between psi l and relative water content obtained on similar leaves. Inferred Pg and Pe both declined immediately after leaf excision. Inferred pi g also declined after a lag period. The kinetics of pi g adjustment after the lag were similar in outdoors and glasshouse plants, but the lag period was much longer in outdoor plants. This suggests that the longer transient opening response in outdoor plants resulted from slower induction, not slower execution, of guard cell osmoregulation. We discuss the implications of our results for the mechanism of short-term stomatal responses to hydraulic perturbations, for dynamic modelling of gs and for leaf water status regulation.
A novel and high‐throughput approach to assess photosynthetic thermal tolerance of kelp using chlorophyll α fluorometry
Publisher: Wiley
Date: 20-12-2023
DOI: 10.1111/JPY.13296
Abstract: Foundation seaweed species are experiencing widespread declines and localized extinctions due to increased instability of sea surface temperature. Characterizing temperature thresholds are useful for predicting patterns of change and identifying species most vulnerable to extremes. Existing methods for characterizing seaweed thermal tolerance produce erse metrics and are often time‐consuming, making comparisons between species and techniques difficult, hindering insight into global patterns of change. Using three kelp species, we adapted a high‐throughput method – previously used in terrestrial plant thermal biology – for use on kelps. This method employs temperature‐dependent fluorescence ( T – F 0 ) curves under heating or cooling regimes to determine the critical temperature ( T crit ) of photosystem II (PSII), i.e., the breakpoint between slow and fast rise fluorescence response to changing temperature, enabling rapid assays of photosynthetic thermal tolerance using a standardized metric. This method enables characterization of T crit for up to 48 s les per two‐hour assay, demonstrating the capacity of T – F 0 curves for high‐throughput assays of thermal tolerance. Temperature‐dependent fluorescence curves and their derived metric, T crit , may offer a timely and powerful new method for the field of phycology, enabling characterization and comparison of photosynthetic thermal tolerance of seaweeds across many populations, species, and biomes.
An innovative approach to using an intensive field course to build scientific and professional skills
Publisher: Wiley
Date: 10-2022
DOI: 10.1002/ECE3.9446
Abstract: This paper reports on the design and evaluation of Field Studies in Functional Ecology (FSFE), a two‐week intensive residential field course that enables students to master core content in functional ecology alongside skills that facilitate their transition from “student” to “scientist.” We provide an overview of the course structure, showing how the constituent elements have been designed and refined over successive iterations of the course. We detail how FSFE students: (1) Work closely with discipline specialists to develop a small group project that tests an hypothesis to answer a genuine scientific question in the field (2) Learn critical skills of data management and communication and (3) Analyze, interpret, and present their results in the format of a scientific symposium. This process is repeated in an iterative “cognitive apprenticeship” model, supported by a series of workshops that name and explicitly instruct the students in “hard” and “soft” skills (e.g., statistics and teamwork, respectively) critically relevant for research and other careers. FSFE students develop a coherent and nuanced understanding of how to approach and execute ecological studies. The sophisticated knowledge and ecological research skills that they develop during the course is demonstrated through high‐quality presentations and peer‐reviewed publications in an open‐access, student‐led journal. We outline our course structure and evaluate its efficacy to show how this novel combination of field course elements allows students to gain maximum value from their educational journey, and to develop cognitive, affective, and reflective tools to help apply their skills as scientists.
Predicting the impact of increasing temperatures on seed germination among populations of Western Australian Banksia (Proteaceae)
Publisher: Cambridge University Press (CUP)
Date: 29-05-2014
DOI: 10.1017/S096025851400018X
Abstract: Temperature is a significant factor influencing seed germination and for many species temperature-mediated germination cues are vital for plant persistence. Rising temperatures forecast as a result of anthropogenic climate change may have a substantial influence on the population and range dynamics of plant species. Here, we report on the thermal constraints on seed germination in natural populations of four congeneric Banksia species collected from a longitudinal climate gradient in Western Australia. We investigated whether germination niche: (1) varied between species (2) varied among populations of each species and (3) varied in a consistent manner reflecting the climatic gradients of seed origin. We hypothesized that species would differ and that populations from warmer sites would have a broader temperature window for germination than populations from cooler sites. Species differed in the breadth of their germination niche, but temperatures that stimulated the most rapid and complete germination were similar across all species. A sharp reduction in germination percentage occurred above the optimum temperature, which coincided with significant delays in germination relative to the optimum. The temperatures causing these declines varied among populations. Across the species, there was a significant correlation between optimum germination temperature and mean annual temperature at seed source however, there was no relationship at the population level for in idual species. These data provide insight into the vulnerability of Banksia species to climate change, with those populations that require lower temperatures for germination, or have narrower optimal ranges for germination, likely to be most vulnerable to a warming climate.
Herbivory differentially affects male and female reproductive traits of Cucumis sativus
Publisher: Wiley
Date: 09-2004
Abstract: Herbivory is an important selection pressure in the life history of plants. Most studies use seed or fruit production as an indication of plant fitness, but the impact of herbivory on male reproductive success is usually ignored. It is possible that plants compensate for resources lost to herbivory by shifting the allocation from seed production to pollen production and export, or vice versa. This study examined the impact of herbivory by Helix aspersa on both male and female reproductive traits of a monoecious plant, Cucumis sativus. The effects of herbivory on the relative allocation to male and female flowers were assessed through measurements of the number and size of flowers of both sexes, and the amount of pollinator visitation. We performed two glasshouse experiments the first looked at the impact of three levels of pre-flowering herbivory, and the second looked at four levels of herbivory after the plants had started to flower. We found that herbivory during the flowering phase led to a significant increase in the number of plants without male flowers. As a consequence there was significantly less pollen export from this population, as estimated by movement of a pollen analog. The size of female flowers was reduced by severe herbivory, but there was no affect on pollen receipt by the female flowers of damaged plants. The decrease in allocation to male function after severe herbivory may be adaptive when male reproductive success is very unpredictable.
The influence of leaf size and shape on leaf thermal dynamics: does theory hold up under natural conditions?
Publisher: Wiley
Date: 27-12-2016
DOI: 10.1111/PCE.12857
Abstract: Laboratory studies on artificial leaves suggest that leaf thermal dynamics are strongly influenced by the two-dimensional size and shape of leaves and associated boundary layer thickness. Hot environments are therefore said to favour selection for small, narrow or dissected leaves. Empirical evidence from real leaves under field conditions is scant and traditionally based on point measurements that do not capture spatial variation in heat load. We used thermal imagery under field conditions to measure the leaf thermal time constant (τ) in summer and the leaf-to-air temperature difference (∆T) and temperature range across laminae (T
Patterns of phenotypic plasticity along a thermal gradient differ by trait type in an alpine plant
Publisher: Wiley
Date: 11-07-2022
Abstract: Climate change presents many challenges for plants, a major one of which is the steady increase in the temperatures that plants are exposed to during germination, growth and reproduction. Generating a more complete understanding of the capacity for plants to respond and of the role that phenotypic plasticity plays in facilitating species' responses to warming temperatures is a central objective in global change ecology. Different traits expressed across life stages might be expected to exhibit a variety of responses to temperature due to phenotypic plasticity and genetic variation, even within a species. However, the extent of the variation among trait types and the relative contribution of plasticity and genetics to responses along a thermal gradient are not well understood. Here, we studied an alpine plant, Wahlenbergia ceracea , to determine the shapes of plastic responses in 14 traits across germination, leaf, physiology and reproductive fitness trait types across a broad thermal gradient of temperatures while also comparing responses among family lines. Trait types differed markedly: germination, leaf and reproductive traits showed nonlinear plasticity with best performance at intermediate temperatures, whereas physiology traits were generally less responsive to temperature. Variation in plasticity among families was lowest for the traits most necessary for tolerating environmental extremes (e.g. heat tolerance), suggesting that physiology traits may be canalised and fitness suffers for it. In contrast, variation in means, and plasticity in some cases, among families in germination traits suggests genetic variation and hence the potential for these few traits to respond to selection. Our results illustrate the variety of responses that may occur in response to temperature, and the frequent occurrence of complex nonlinear plastic responses that would not have been apparent with comparison of fewer temperatures. We discuss the physiological, ecological and evolutionary insights our findings provide into the response of wild species to the changing climate. Read the free Plain Language Summary for this article on the Journal blog.
The Impact of a 24-h Low and High Fermentable Oligo- Di- Mono-Saccharides and Polyol (FODMAP) Diet on Plasma Bacterial Profile in Response to Exertional-Heat Stress
Publisher: MDPI AG
Date: 29-07-2023
DOI: 10.3390/NU15153376
Abstract: Exertional-heat stress (EHS) compromises intestinal epithelial integrity, potentially leading to the translocation of pathogenic agents into circulation. This study aimed to explore the impact of EHS on the systemic circulatory bacterial profile and to determine the impact of a short-term low (LFOD) and high (HFOD) fermentable oligo- di- mono-saccharide and polyol dietary intervention before EHS on this profile. Using a double-blind randomized cross-over design, thirteen endurance runners (n = 8 males, n = 5 females), with a history of exercise-associated gastrointestinal symptoms (Ex-GIS), consumed a 24 h LFOD and HFOD before 2 h running at 60% V.O2max in 35.6 °C. Blood and fecal s les were collected pre-EHS to determine plasma microbial DNA concentration, and s le bacteria and short chain fatty acid (SCFA) profiles by fluorometer quantification, 16S rRNA licon gene sequencing, and gas chromatography, respectively. Blood s les were also collected post-EHS to determine changes in plasma bacteria. EHS increased plasma microbial DNA similarly in both FODMAP trials (0.019 ng·μL−1 to 0.082 ng·μL−1) (p 0.01). Similar pre- to post-EHS increases in plasma Proteobacteria (+1.6%) and Firmicutes (+0.6%) phyla relative abundance were observed in both FODMAP trials. This included increases in several Proteobacteria genus (Delftia and Serratia) groups. LFOD presented higher fecal Firmicutes (74%) and lower Bacteroidota (10%) relative abundance pre-EHS, as a result of an increase in Ruminococcaceae and Lachnospiraceae family and respective genus groups, compared with HFOD (64% and 25%, respectively). Pre-EHS plasma total SCFA (p = 0.040) and acetate (p = 0.036) concentrations were higher for HFOD (188 and 178 μmol·L−1, respectively) vs. LFOD (163 and 153 μmol·L−1, respectively). Pre-EHS total fecal SCFA concentration (119 and 74 μmol·g−1 p 0.001), including acetate (74 and 45 μmol·g−1 p = 0.001), butyrate (22 and 13 μmol·g−1 p = 0.002), and propionate (20 and 13 μmol·g−1 p = 0.011), were higher on HFOD vs LFOD, respectively. EHS causes the translocation of whole bacteria into systemic circulation and alterations to the plasma bacterial profile, but the FODMAP content of a 24 h diet beforehand does not alter this outcome.
Reproductive allocation in a gender dimorphic shrub: anomalous female investment in Gynatrix pulchella?
Publisher: Wiley
Date: 11-2011
Highly permeable membrane materials for CO2 capture
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA13066E
AusTraits, a curated plant trait database for the Australian flora
Publisher: Springer Science and Business Media LLC
Date: 30-09-2021
DOI: 10.1038/S41597-021-01006-6
Abstract: We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field c aigns, published literature, taxonomic monographs, and in idual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised in idual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
Population and phylogenomic decomposition via genotyping-by-sequencing in Australian Pelargonium
Publisher: Wiley
Date: 05-2016
DOI: 10.1111/MEC.13584
Abstract: Species delimitation has seen a paradigm shift as increasing accessibility of genomic-scale data enables separation of lineages with convergent morphological traits and the merging of recently erged ecotypes that have distinguishing characteristics. We inferred the process of lineage formation among Australian species in the widespread and highly variable genus Pelargonium by combining phylogenomic and population genomic analyses along with breeding system studies and character analysis. Phylogenomic analysis and population genetic clustering supported seven of the eight currently described species but provided little evidence for differences in genetic structure within the most widely distributed group that containing P. australe. In contrast, morphometric analysis detected three deep lineages within Australian Pelargonium with P. australe consisting of five previously unrecognized entities occupying separate geographic ranges. The genomic approach enabled elucidation of parallel evolution in some traits formerly used to delineate species, as well as identification of ecotypic morphological differentiation within recognized species. Highly variable morphology and trait convergence each contribute to the discordance between phylogenomic relationships and morphological taxonomy. Data suggest that genetic ergence among species within the Australian Pelargonium may result from allopatric speciation while morphological differentiation within and among species may be more strongly driven by environmental differences.
Adaptive phenotypic plasticity and plant water use
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/FP09139
Abstract: The emergence of new techniques in plant science, including molecular and phenomic tools, presents a novel opportunity to re-evaluate the way we examine the phenotype. Our increasing capacity for phenotyping means that not only can we consider increasing numbers of species or varieties, but also that we can effectively quantify the phenotypes of these different genotypes under a range of environmental conditions. The phenotypic plasticity of a given genotype, or the range of phenotypes, that can be expressed dependent upon environment becomes something we can feasibly assess. Of particular importance is phenotypic variation that increases fitness or survival – adaptive phenotypic plasticity. Here, we examine the case of adaptive phenotypic plasticity in plant water use traits and consider how taking an ecological and evolutionary perspective on plasticity in these traits might have relevance for agriculture, horticulture and the management of native and invasive plant species in an era of rapid climate change.
Will among-population variation in seed traits improve the chance of species persistence under climate change?
Publisher: Wiley
Date: 10-10-2015
DOI: 10.1111/GEB.12234
Changes in Whole-Tree Water Use Following Live-Crown Pruning in Young Plantation-Grown Eucalyptus pilularis and Eucalyptus cloeziana
Publisher: MDPI AG
Date: 05-02-2013
DOI: 10.3390/F4010106
The Impact of Beneficial Plant-Associated Microbes on Plant Phenotypic Plasticity
Publisher: Springer Science and Business Media LLC
Date: 07-2013
The effects of phenotypic plasticity and local adaptation on forecasts of species range shifts under climate change
Publisher: Wiley
Date: 09-09-2014
DOI: 10.1111/ELE.12348
Abstract: Species are the unit of analysis in many global change and conservation biology studies however, species are not uniform entities but are composed of different, sometimes locally adapted, populations differing in plasticity. We examined how intraspecific variation in thermal niches and phenotypic plasticity will affect species distributions in a warming climate. We first developed a conceptual model linking plasticity and niche breadth, providing five alternative intraspecific scenarios that are consistent with existing literature. Secondly, we used ecological niche-modeling techniques to quantify the impact of each intraspecific scenario on the distribution of a virtual species across a geographically realistic setting. Finally, we performed an analogous modeling exercise using real data on the climatic niches of different tree provenances. We show that when population differentiation is accounted for and dispersal is restricted, forecasts of species range shifts under climate change are even more pessimistic than those using the conventional assumption of homogeneously high plasticity across a species' range. Suitable population-level data are not available for most species so identifying general patterns of population differentiation could fill this gap. However, the literature review revealed contrasting patterns among species, urging greater levels of integration among empirical, modeling and theoretical research on intraspecific phenotypic variation.
Sour grapes: addressing the challenges in utilizing vinegar and SCFAs to treat dysregulated glycemic responses
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1093/AJCN/NQAC134
Compensation for herbivory by Cucumis sativus through increased photosynthetic capacity and efficiency
Publisher: Springer Science and Business Media LLC
Date: 2003
DOI: 10.1007/S00442-002-1102-6
Abstract: Herbivory is an important selective pressure in the life history of most plant species, as it usually results in reduced plant fitness. In some situations, however, plants are able to compensate for the resources lost to herbivory and do not suffer any reduction in growth or reproduction after attack. We examined the ability of Lebanese cucumber (Cucumis sativus) to compensate for both pre-flowering and during-flowering foliar herbivory through increased photosynthetic efficiency and capacity. Plants that were damaged before flowering were able to compensate, in terms of vegetative biomass and fruit production for up to 80% leaf area loss. Plants that were damaged during the flowering period were less able to compensate and fruit production declined with increasing herbivory. Damaged plants had higher photosynthetic efficiency and capacity, and dissipated less light energy as heat. Herbivore-damaged plants may be induced to use a greater proportion of the absorbed light energy for photosynthesis as a result of altered carbohydrate source-sink relationships.
Structural and hydraulic correlates of heterophylly in Ginkgo biloba
Publisher: Wiley
Date: 29-09-2011
DOI: 10.1111/J.1469-8137.2010.03476.X
Abstract: This study investigates the functional significance of heterophylly in Ginkgo biloba, where leaves borne on short shoots are ontogenetically distinct from those on long shoots. Short shoots are compact, with minimal internodal elongation their leaves are supplied with water through mature branches. Long shoots extend the canopy and have significant internodal elongation their expanding leaves receive water from a shoot that is itself maturing. Morphology, stomatal traits, hydraulic architecture, Huber values, water transport efficiency, in situ gas exchange and laboratory-based steady-state hydraulic conductance were examined for each leaf type. Both structure and physiology differed markedly between the two leaf types. Short-shoot leaves were thinner and had higher vein density, lower stomatal pore index, smaller bundle sheath extensions and lower hydraulic conductance than long-shoot leaves. Long shoots had lower xylem area:leaf area ratios than short shoots during leaf expansion, but this ratio was reversed at shoot maturity. Long-shoot leaves had higher rates of photosynthesis, stomatal conductance and transpiration than short-shoot leaves. We propose that structural differences between the two G. biloba leaf types reflect greater hydraulic limitation of long-shoot leaves during expansion. In turn, differences in physiological performance of short- and long-shoot leaves correspond to their distinct ontogeny and architecture.
The Role of Diet and Gut Microbiota in Regulating Gastrointestinal and Inflammatory Disease
Publisher: Frontiers Media SA
Date: 05-04-2022
DOI: 10.3389/FIMMU.2022.866059
Abstract: Diet is an important lifestyle factor that is known to contribute in the development of human disease. It is well established that poor diet plays an active role in exacerbating metabolic diseases, such as obesity, diabetes and hypertension. Our understanding of how the immune system drives chronic inflammation and disease pathogenesis has evolved in recent years. However, the contribution of dietary factors to inflammatory conditions such as inflammatory bowel disease, multiple sclerosis and arthritis remain poorly defined. A western diet has been associated as pro-inflammatory, in contrast to traditional dietary patterns that are associated as being anti-inflammatory. This may be due to direct effects of nutrients on immune cell function. Diet may also affect the composition and function of gut microbiota, which consequently affects immunity. In animal models of inflammatory disease, diet may modulate inflammation in the gastrointestinal tract and in other peripheral sites. Despite limitations of animal models, there is now emerging evidence to show that anti-inflammatory effects of diet may translate to human gastrointestinal and inflammatory diseases. However, appropriately designed, larger clinical studies must be conducted to confirm the therapeutic benefit of dietary therapy.
Reproductive allocation and the long-term costs of reproduction in Siparuna grandiflora, a dioecious neo-tropical shrub
Publisher: Wiley
Date: 1999
Inherent conflicts between reaction norm slope and plasticity indices when comparing plasticity: a conceptual framework and empirical test
Publisher: Springer Science and Business Media LLC
Date: 07-02-2022
DOI: 10.1007/S00442-022-05122-X
Abstract: Phenotypic plasticity index (PI), the slope of reaction norm (K) and relative distances plasticity index (RDPI), the most commonly used estimators, have occasionally been found to generate different plasticity rankings between groups (species, populations, cultivars or genotypes). However, no effort has been made to determine how frequent this incongruence is, and the factors that influence the occurrence of the incongruence. To address these problems, we first proposed a conceptual framework and then tested the framework (its predictions) by reanalyzing 1248 sets of published data. Our framework reveals inherent conflicts between K and PI or RDPI when comparing plasticity between two groups, and the frequency of these conflicts increases with increasing inter-group initial trait difference and/or K values of the groups compared. More importantly, the estimators also affect the magnitude of the inter-group plasticity differences even when they do not change groups' plasticity rankings. The above-mentioned effects of plasticity estimators were confirmed by our empirical test using data from the literature, and the conflicts occur in 203 (16%) of the 1248 comparisons between K and indices, indicating that a considerable proportion of the comparative conclusions on plasticity in literature are estimator-dependent. The frequency of the conflicts is influenced by phylogenetic relatedness of the groups compared, being lower when comparing within relative to between species, but not by specific types of environments, traits and species. Our study indicates that care is needed to select estimator when comparing groups' plasticity, and that the conclusions in relevant literature should be treated with great caution.
Decoupling the effects of parental and offspring warming on seed and seedling traits
Publisher: Springer Science and Business Media LLC
Date: 04-03-2021
Differences in seedling water-stress response of two co-occurring Banksia species
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/BT15022
Abstract: In the South-west Australian Floristic Region, timing of rainfall is critical for successful seedling establishment, as is surviving the first year’s summer drought for population persistence. Predictions of a warmer, drier future, therefore, threaten the persistence of obligate seeding species. Here, we investigate the drought tolerance of two co-occurring Banksia (Proteaceae) species by withholding water in pots to different extents of soil drying. Seed was collected from high- and low-rainfall populations, to test for niche differentiation in water-use strategies at the species level, as well as population differentiation. On the basis of a more negative leaf water potential at minimal levels of stomatal conductance and quantum yield, B. coccinea was considered to be more drought tolerant than B. baxteri. This was supported at the anatomical level according to xylem-vessel attributes, with a higher estimated collapse pressure suggesting that B. coccinea is less vulnerable to xylem cavitation. Population contrasts were observed mainly for B. baxteri, with a lower leaf-expansion increment rate in the low-rainfall population providing for drought avoidance, which was reflected in a higher rate of survival than with the high-rainfall population in which 87.5% of plants showed complete leaf senescence. The implications of species differences in water-use strategies are that community dynamics may start to shift as the climate changes. Importantly, this shift may be population dependent. A systematic understanding of adaptive capacity will help inform the choice of population for use in revegetation programs, which may lead to increased resilience and persistence in the face of environmental change. The results of the present study suggest that should declines in B. baxteri populations be noted, revegetating with seed collected from the low-rainfall population may help improve the chances of this species surviving into the future.
Genes controlling legume nodule numbers affect phenotypic plasticity responses to nitrogen in the presence and absence of rhizobia
Publisher: Wiley
Date: 20-12-2019
DOI: 10.1111/PCE.13498
Abstract: We investigated the role of three autoregulation of nodulation (AON) genes in regulating of root and shoot phenotypes when responding to changing nitrogen availability in the model legume, Medicago truncatula. These genes, RDN1-1 (ROOT DETERMINED NODULATION1-1), SUNN (SUPER NUMERIC NODULES), and LSS (LIKE SUNN SUPERNODULAOR), act in a systemic signalling pathway that limits nodule numbers. This pathway is also influenced by nitrogen availability, but it is not well known if AON genes control root and shoot phenotypes other than nodule numbers in response to nitrogen. We conducted a controlled glasshouse experiment to compare root and shoot phenotypes of mutants and wild type plants treated with four nitrate concentrations. All AON mutants showed altered rhizobia-independent phenotypes, including biomass allocation, lateral root length, lateral root density, and root length ratio. In response to nitrogen, uninoculated AON mutants were less plastic than the wild type in controlling root mass ratio, root length ratio, and lateral root length. This suggests that AON genes control nodulation-independent root architecture phenotypes in response to nitrogen. The phenotypic differences between wild type and AON mutants were exacerbated by the presence of nodules, pointing to resource competition as an additional mechanism affecting root and shoot responses to nitrogen.
Sparse evidence for selection on phenotypic plasticity in response to temperature.
Publisher: The Royal Society
Date: 28-01-2019
Abstract: Phenotypic plasticity is frequently assumed to be an adaptive mechanism by which organisms cope with rapid changes in their environment, such as shifts in temperature regimes owing to climate change. However, despite this adaptive assumption, the nature of selection on plasticity within populations is still poorly documented. Here, we performed a systematic review and meta-analysis of estimates of selection on thermal plasticity. Although there is a large literature on thermal plasticity, we found very few studies that estimated coefficients of selection on measures of plasticity. Those that did do not provide strong support for selection on plasticity, with the majority of estimates of directional selection on plasticity being weak and non-significant, and no evidence for selection on plasticity overall. Although further estimates are clearly needed before general conclusions can be drawn, at present there is not clear empirical support for any assumption that plasticity in response to temperature is under selection. We present a multivariate mixed model approach for robust estimation of selection on plasticity and demonstrate how it can be implemented. Finally, we highlight the need to consider the environments, traits and conditions under which plasticity is (or is not) likely to be under selection, if we are to understand phenotypic responses to rapid environmental change. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.
A quantitative analysis of microalgal lipids for optimization of biodiesel and omega-3 production
Publisher: Wiley
Date: 09-02-2013
DOI: 10.1002/BIT.24844
Improving Conservation Outcomes with a New Paradigm for Understanding Species' Fundamental and Realized Adaptive Capacity
Publisher: Wiley
Date: 05-08-2016
DOI: 10.1111/CONL.12190
Assets-based approaches and dementia-friendly communities.
Publisher: SAGE Publications
Date: 04-01-2018
The phenotypic response of co-occurring Banksia species to warming and drying
Publisher: Springer Science and Business Media LLC
Date: 23-09-2015
Sexual dimorphism in reproductive allocation and water use efficiency in Maireana pyramidata (Chenopodiaceae), a dioecious, semi-arid shrub
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/BT03043
Abstract: Sexual dimorphism in dioecious plant species is widely attributed to the differential impacts of reproduction on male v. female plants. We investigated sexual dimorphism in reproductive, morphological and physiological traits of Maireana pyramidata (Benth.) Paul G.Wilson (Chenopodiaceae), a dioecious, semi-arid shrub endemic to Australia. We estimated reproductive allocation for each sex by calculating the relative biomass allocated to flowers and fruits per gram of leaf tissue, based on one branch per s le plant. Morphological measurements included leaf mass, stem mass, specific leaf area, plant height and plant leaf area index. We also measured leaf nitrogen and chlorophyll, gas exchange and Δ13C. Reproductive allocation was nine times greater in females than in males. No significant difference between the sexes in photosynthetic rate or transpiration could be detected but instantaneous water use efficiency (photosynthesis/transpiration) was significantly lower in females than in males during the fruiting period. Δ13C did not differ between the sexes. The results indicate that greater reproductive allocation in females has an immediate impact on their capacity for conservative water use but does not lead to long-term differences in water use efficiency.
EXTENT OF SOLAR TRACKING DIFFERS BETWEEN TWO CO-OCCURRING CONGENERIC GEOPHYTES THAT DIFFER IN LEAF SHAPE
Publisher: University of Chicago Press
Date: 02-2018
DOI: 10.1086/695698
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