ORCID Profile
0000-0003-0988-4351
Current Organisation
Western Sydney 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)
Terrestrial Ecology | Plant Physiology | Ecology | Ecological Impacts of Climate Change | Ecological Applications | Genetics | Population, Ecological and Evolutionary Genetics | Ecological Physiology | Biological Adaptation | Global Change Biology
ANZSRC Socio-Economic Objective (SEO)
Native Forests | Forest and Woodlands Flora, Fauna and Biodiversity | Ecosystem Adaptation to Climate Change | Management of Water Consumption by Plant Production | Rehabilitation of Degraded Forest and Woodlands Environments | Flora, Fauna and Biodiversity at Regional or Larger Scales | Forest and Woodlands Land Management |
Related Links
Publications
Adaptive plasticity in plant traits increases time to hydraulic failure under drought in a foundation tree
Publisher: Cold Spring Harbor Laboratory
Date: 20-08-2020
DOI: 10.1101/2020.08.19.258186
Abstract: The viability of forest trees, in response to climate change-associated drought, will depend on their capacity to survive through genetic adaptation and phenotypic plasticity in drought tolerance traits. Genotypes with enhanced plasticity for drought tolerance (adaptive plasticity) will have a greater ability to persist and delay the onset of hydraulic failure. Corymbia calophylla populations from two contrasting climate-origins (warm-dry and cool-wet) were grown under well-watered and chronic soil water deficit treatments in large containers. Hydraulic and allometric traits were measured and then trees were dried-down to critical levels of drought stress. Significant plasticity was detected in the warm-dry population in response to water-deficit, with adjustments in drought tolerance traits that resulted in longer dry-down times from stomatal closure to 88% loss of stem hydraulic conductance (time to hydraulic failure, THF). Plasticity was limited in the cool-wet population, indicating a significant genotype-by-environment interaction in THF. Our findings contribute information on intraspecific variation in key drought tolerance traits and THF. It highlights the need to quantify adaptive capacity in populations of forest trees facing climate change-type drought to improve predictions of forest die-back. Corymbia calophylla may benefit from assisted gene migration by introducing adaptive warm-dry populations into vulnerable cool-wet population regions.
Signatures of natural selection in a foundation tree along Mediterranean climatic gradients
Publisher: Wiley
Date: 27-01-2022
DOI: 10.1111/MEC.16351
Abstract: Temperature and precipitation regimes are rapidly changing, resulting in forest dieback and extinction events, particularly in Mediterranean-type climates (MTC). Forest management that enhance forests' resilience is urgently required, however adaptation to climates in heterogeneous landscapes with multiple selection pressures is complex. For widespread trees in MTC we hypothesized that: patterns of local adaptation are associated with climate precipitation is a stronger factor of adaptation than temperature functionally related genes show similar signatures of adaptation and adaptive variants are independently sorting across the landscape. We s led 28 populations across the geographic distribution of Eucalyptus marginata (jarrah), in South-west Western Australia, and obtained 13,534 independent single nucleotide polymorphic (SNP) markers across the genome. Three genotype-association analyses that employ different ways of correcting population structure were used to identify putatively adapted SNPs associated with independent climate variables. While overall levels of population differentiation were low (F
Xylem embolism measured retrospectively is linked to canopy dieback in natural populations of Eucalyptus piperita following drought
Publisher: Oxford University Press (OUP)
Date: 11-05-2018
Abstract: Manipulative experiments have suggested that embolism-induced hydraulic impairment underpins widespread tree mortality during extreme drought, yet in situ evidence is rare. One month after drought-induced leaf and branch dieback was observed in field populations of Eucalyptus piperita Sm. in the Blue Mountains (Australia), we measured the level of native stem embolism and characterized the extent of leaf death in co-occurring dieback and healthy (non-dieback) trees. We found that canopy dieback-affected trees showed significantly higher levels of native embolism (26%) in tertiary order branchlets than healthy trees (11%). Furthermore, there was a significant positive correlation (R2 = 0.51) between the level of leaf death and the level of native embolism recorded in branchlets from dieback-affected trees. This retrospective study suggests that hydraulic failure was the primary mechanism of leaf and branch dieback in response to a natural drought event in the field. It also suggests that post-drought embolism refilling is minimal or absent in this species of eucalypt.
Remarkable Resilience of Forest Structure and Biodiversity Following Fire in the Peri-Urban Bushland of Sydney, Australia
Publisher: MDPI AG
Date: 16-06-2022
DOI: 10.3390/CLI10060086
Abstract: In rapidly urbanizing areas, natural vegetation becomes fragmented, making conservation planning challenging, particularly as climate change accelerates fire risk. We studied urban forest fragments in two threatened eucalypt-dominated (scribbly gum woodland, SGW, and ironbark forest, IF) communities across ~2000 ha near Sydney, Australia, to evaluate effects of fire frequency (0–4 in last 25 years) and time since fire (0.5 to years) on canopy structure, habitat quality and bio ersity (e.g., species richness). Airborne lidar was used to assess canopy height and density, and ground-based surveys of 148 (400 m2) plots measured leaf area index (LAI), plant species composition and habitat metrics such as litter cover and hollow-bearing trees. LAI, canopy density, litter, and microbiotic soil crust increased with time since fire in both communities, while tree and mistletoe cover increased in IF. Unexpectedly, plant species richness increased with fire frequency, owing to increased shrub richness which offset decreased tree richness in both communities. These findings indicate bio ersity and canopy structure are generally resilient to a range of times since fire and fire frequencies across this study area. Nevertheless, reduced arboreal habitat quality and subtle shifts in community composition of resprouters and obligate seeders signal early concern for a scenario of increasing fire frequency under climate change. Ongoing assessment of fire responses is needed to ensure that bio ersity, canopy structure and ecosystem function are maintained in the remaining fragments of urban forests under future climate change which will likely drive hotter and more frequent fires.
Range size and growth temperature influence Eucalyptus species responses to an experimental heatwave.
Publisher: Wiley
Date: 10-03-2019
DOI: 10.1111/GCB.14590
Abstract: Understanding forest tree responses to climate warming and heatwaves is important for predicting changes in tree species ersity, forest C uptake, and vegetation-climate interactions. Yet, tree species differences in heatwave tolerance and their plasticity to growth temperature remain poorly understood. In this study, populations of four Eucalyptus species, two with large range sizes and two with comparatively small range sizes, were grown under two temperature treatments (cool and warm) before being exposed to an equivalent experimental heatwave. We tested whether the species with large and small range sizes differed in heatwave tolerance, and whether trees grown under warmer temperatures were more tolerant of heatwave conditions than trees grown under cooler temperatures. Visible heatwave damage was more common and severe in the species with small rather than large range sizes. In general, species that showed less tissue damage maintained higher stomatal conductance, lower leaf temperatures, larger increases in isoprene emissions, and less photosynthetic inhibition than species that showed more damage. Species exhibiting more severe visible damage had larger increases in heat shock proteins (HSPs) and respiratory thermotolerance (T
The interaction of clonality, breeding system and genomics for a highly threatened plant species and the management implications
Publisher: Springer Science and Business Media LLC
Date: 06-07-2020
Does genetic variation and gene flow vary with rarity in obligate seeding Persoonia species (Proteaceae)?
Publisher: Springer Science and Business Media LLC
Date: 19-10-2006
Intra-specific trait variation remains hidden in the environment
Publisher: Wiley
Date: 26-10-2021
DOI: 10.1111/NPH.16959
Abstract: This article is a Commentary on Anderegg et al . (2021), 229: 1375–1387 .
Tree hydraulic traits are coordinated and strongly linked to climate-of-origin across a rainfall gradient
Publisher: Wiley
Date: 29-01-2018
DOI: 10.1111/PCE.13129
Abstract: Plant hydraulic traits capture the impacts of drought stress on plant function, yet vegetation models lack sufficient information regarding trait coordination and variation with climate-of-origin across species. Here, we investigated key hydraulic and carbon economy traits of 12 woody species in Australia from a broad climatic gradient, with the aim of identifying the coordination among these traits and the role of climate in shaping cross-species trait variation. The influence of environmental variation was minimized by a common garden approach, allowing us to factor out the influence of environment on phenotypic variation across species. We found that hydraulic traits (leaf turgor loss point, stomatal sensitivity to drought [P
Isolation and characterization of microsatellite markers for the neotropical tree, Pachira quinata (Malvaceae)
Publisher: Springer Science and Business Media LLC
Date: 20-02-2014
Adaptation and acclimation both influence photosynthetic and respiratory temperature responses in Corymbia calophylla
Publisher: Oxford University Press (OUP)
Date: 28-04-2017
Abstract: Short-term acclimation and long-term adaptation represent two ways in which forest trees can respond to changes in temperature. Yet, the relative contribution of thermal acclimation and adaptation to tree physiological responses to temperature remains poorly understood. Here, we grew two cool-origin and two warm-origin populations of a widespread broad-leaved evergreen tree species (Corymbia calophylla (Lindl.) K.D.Hill & L.A.S.Johnson) from a Mediterranean climate in southwestern Australia under two growth temperatures representative of the cool- and warm-edge of the species distribution. The populations selected from each thermal environment represented both high and low precipitation sites. We measured the short-term temperature response of leaf photosynthesis (A) and dark respiration (R), and attributed observed variation to acclimation, adaptation or the combination of both. We observed limited variation in the temperature optimum (Topt) of A between temperature treatments or among populations, suggesting little plasticity or genetic differentiation in the Topt of A. Yet, other aspects of the temperature response of A and R were dependent upon population and growth temperature. Under cooler growth temperatures, the population from the coolest, wettest environment had the lowest A (at 25 °C) among all four populations, but exhibited the highest A (at 25 °C) under warmer growth temperatures. Populations varied in R (at 20 °C) and the temperature sensitivity of R (i.e., Q10 or activation energy) under cool, but not warm growth temperatures. However, populations showed similar yet lower R (at 20 °C) and no differences in the temperature sensitivity of R under warmer growth temperatures. We conclude that C. calophylla populations from contrasting climates vary in physiological acclimation to temperature, which might influence how this ecologically important tree species and the forests of southwestern Australia respond to climate change.
Intraspecific variation in plant responses to atmospheric CO2, temperature and water availability
Publisher: Springer International Publishing
Date: 2021
Genetic adaptation and phenotypic plasticity contribute to greater leaf hydraulic tolerance in response to drought in warmer climates
Publisher: Oxford University Press (OUP)
Date: 09-02-2017
Abstract: The ability of plants to maintain an intact water transport system in leaves under drought conditions is intimately linked to survival and can been be seen as adaptive in shaping species climatic limits. Large differences in leaf hydraulic vulnerability to drought are known among species from contrasting climates, yet whether this trait varies among populations within a single species and, furthermore, whether it is altered by changes in growth conditions, remain unclear. We examined intraspecific variation in both leaf water transport capacity (Kleaf) and leaf hydraulic vulnerability to drought (P50leaf) among eight populations of Corymbia calophylla (R. Br.) K.D. Hill & L.A.S. Johnson (Myrtaceae) from both cool and warm climatic regions grown reciprocally under two temperature treatments representing the cool and warm edge of the species distribution. Kleaf did not vary between cool and warm-climate populations, nor was it affected by variable growth temperature. In contrast, population origin and growth temperature independently altered P50leaf. Using data pooled across growth temperatures, cool-climate populations showed significantly higher leaf hydraulic vulnerability (P50leaf = -3.55 ± 0.18 MPa) than warm-climate populations (P50leaf = -3.78 ± 0.08 MPa). Across populations, P50leaf decreased as population home-climate temperature increased, but was unrelated to rainfall and aridity. For populations from both cool and warm climatic regions, P50leaf was lower under the warmer growth conditions. These results provide evidence of trait plasticity in leaf hydraulic vulnerability to drought in response to variable growth temperature. Furthermore, they suggest that climate, and in particular temperature, may be a strong selective force in shaping intraspecific variation in leaf hydraulic vulnerability to drought.
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.
An ancient and a recent colonization of islands by an Australian sap-feeding insect
Publisher: Wiley
Date: 10-08-2018
DOI: 10.1111/JBI.13416
Major biogeographic barriers in eastern Australia have shaped the population structure of widely distributed Eucalyptus moluccana and its putative subspecies
Publisher: Wiley
Date: 30-09-2021
DOI: 10.1002/ECE3.8169
Abstract: We have investigated the impact of recognized biogeographic barriers on genetic differentiation of grey box ( Eucalyptus moluccana ), a common and widespread tree species of the family Myrtaceae in eastern Australian woodlands, and its previously proposed four subspecies moluccana , pedicellata , queenslandica , and crassifolia . A range of phylogeographic analyses were conducted to examine the population genetic differentiation and subspecies genetic structure in E. moluccana in relation to biogeographic barriers. Slow evolving markers uncovering long term processes (chloroplast DNA) were used to generate a haplotype network and infer phylogeographic barriers. Additionally, fast evolving, hypervariable markers (microsatellites) were used to estimate demographic processes and genetic structure among five geographic regions (29 populations) across the entire distribution of E. moluccana . Morphological features of seedlings, such as leaf and stem traits, were assessed to evaluate population clusters and test differentiation of the putative subspecies. Haplotype network analysis revealed twenty chloroplast haplotypes with a main haplotype in a central position shared by in iduals belonging to the regions containing the four putative subspecies. Microsatellite analysis detected the genetic structure between Queensland (QLD) and New South Wales (NSW) populations, consistent with the McPherson Range barrier, an east‐west spur of the Great Dividing Range. The substructure was detected within QLD and NSW in line with other barriers in eastern Australia. The morphological analyses supported differentiation between QLD and NSW populations, with no difference within QLD, yet some differentiation within NSW populations. Our molecular and morphological analyses provide evidence that several geographic barriers in eastern Australia, including the Burdekin Gap and the McPherson Range have contributed to the genetic structure of E. moluccana . Genetic differentiation among E. moluccana populations supports the recognition of some but not all the four previously proposed subspecies, with crassifolia being the most differentiated.
Photosynthesis and carbon allocation are both important predictors of genotype productivity responses to elevated CO2 in Eucalyptus camaldulensis
Publisher: Oxford University Press (OUP)
Date: 08-05-2018
Abstract: Intraspecific variation in biomass production responses to elevated atmospheric carbon dioxide (eCO2) could influence tree species' ecological and evolutionary responses to climate change. However, the physiological mechanisms underlying genotypic variation in responsiveness to eCO2 remain poorly understood. In this study, we grew 17 Eucalyptus camaldulensis Dehnh. subsp. camaldulensis genotypes (representing provenances from four different climates) under ambient atmospheric CO2 and eCO2. We tested whether genotype leaf-scale photosynthetic and whole-tree carbon (C) allocation responses to eCO2 were predictive of genotype biomass production responses to eCO2. Averaged across genotypes, growth at eCO2 increased in situ leaf net photosynthesis (Anet) (29%) and leaf starch concentrations (37%). Growth at eCO2 reduced the maximum carboxylation capacity of Rubisco (-4%) and leaf nitrogen per unit area (Narea, -6%), but Narea calculated on a total non-structural carbohydrate-free basis was similar between treatments. Growth at eCO2 also increased biomass production and altered C allocation by reducing leaf area ratio (-11%) and stem mass fraction (SMF, -9%), and increasing leaf mass area (18%) and leaf mass fraction (5%). Overall, we found few significant CO2 × provenance or CO2 × genotype (within provenance) interactions. However, genotypes that showed the largest increases in total dry mass at eCO2 had larger increases in root mass fraction (with larger decreases in SMF) and photosynthetic nitrogen-use efficiency (PNUE) with CO2 enrichment. These results indicate that genetic differences in PNUE and carbon sink utilization (in roots) are both important predictors of tree productivity responsiveness to eCO2.
Standing genomic variation within coding and regulatory regions contributes to the adaptive capacity to climate in a foundation tree species
Publisher: Wiley
Date: 05-2019
DOI: 10.1111/MEC.15092
Abstract: Global climate is rapidly changing, and the ability for tree species to adapt is dependent on standing genomic variation however, the distribution and abundance of functional and adaptive variants are poorly understood in natural systems. We test key hypotheses regarding the genetics of adaptive variation in a foundation tree: genomic variation is associated with climate, and genomic variation is more likely to be associated with temperature than precipitation or aridity. To test these hypotheses, we used 9,593 independent, genomic single-nucleotide polymorphisms (SNPs) from 270 in iduals s led from Corymbia calophylla's entire distribution in south-western Western Australia, spanning orthogonal temperature and precipitation gradients. Environmental association analyses returned 537 unique SNPs putatively adaptive to climate. We identified SNPs associated with climatic variation (i.e., temperature [458], precipitation [75] and aridity [78]) across the landscape. Of these, 78 SNPs were nonsynonymous (NS), while 26 SNPs were found within gene regulatory regions. The NS and regulatory candidate SNPs associated with temperature explained more deviance (27.35%) than precipitation (5.93%) and aridity (4.77%), suggesting that temperature provides stronger adaptive signals than precipitation. Genes associated with adaptive variants include functions important in stress responses to temperature and precipitation. Patterns of allelic turnover of NS and regulatory SNPs show small patterns of change through climate space with the exception of an aldehyde dehydrogenase gene variant with 80% allelic turnover with temperature. Together, these findings provide evidence for the presence of adaptive variation to climate in a foundation species and provide critical information to guide adaptive management practices.
Plant functional traits differ in adaptability and are predicted to be differentially affected by climate change
Publisher: Wiley
Date: 28-11-2019
DOI: 10.1002/ECE3.5890
More than iso/anisohydry: Hydroscapes integrate plant water use and drought tolerance traits in 10 eucalypt species from contrasting climates
Publisher: Wiley
Date: 07-04-2019
Assessing climate risk to support urban forests in a changing climate
Publisher: Wiley
Date: 18-01-2022
DOI: 10.1002/PPP3.10240
Abstract: Globally, cities are planning for resilience through urban greening initiatives as governments understand the importance of urban forests in improving quality of life and mitigating climate change. However, the persistence of urban forests and the ecosystem benefits they provide are threatened by climate change, and systematic assessments of causes of tree dieback and mortality in urban environments are rare. Long‐term monitoring studies and adaptive management are needed to identify and prevent climate change‐driven failures and mortality. Research and monitoring when coupled with systematic forecasting will enable governments to incorporate climate change resilience into urban forestry planning. Future scenarios in which urban forests are resilient or in decline will depend on the management and planning actions we make today. The management of urban forests is a key element of resilience planning in cities across the globe. Urban forests provide ecosystem services as well as other nature‐based solutions to 4.2 billion people living in cities. However, to continue to do so effectively, urban forests need to be able to thrive in an increasingly changing climate. Trees in cities are vulnerable to extreme heat and drought events, which are predicted to increase in frequency and severity under climate change. Knowledge of species' vulnerability to climate change, therefore, is crucial to ensure provision of desired ecosystem benefits, improve species selection, maintain tree growth and reduce tree mortality, dieback and stress in urban forests. Yet, systematic assessments of causes of tree dieback and mortality in urban environments are rare. We reviewed the state of knowledge of tree mortality in urban forests globally, finding very few frameworks that enable detection of climate change impacts on urban forests and no long‐term studies assessing climate change as a direct driver of urban tree dieback and mortality. The effects of climate change on urban forests remain poorly understood and quantified, constraining the ability of governments to incorporate climate change resilience into urban forestry planning.
Adaptive plasticity in plant traits increases time to hydraulic failure under drought in a foundation tree
Publisher: Oxford University Press (OUP)
Date: 26-07-2021
Abstract: The viability of forest trees, in response to climate change-associated drought, will depend on their capacity to survive through genetic adaptation and phenotypic plasticity in drought tolerance traits. Genotypes with enhanced plasticity for drought tolerance (adaptive plasticity) will have a greater ability to persist and delay the onset of hydraulic failure. By examining populations from different climate-origins grown under contrasting soil water availability, we tested for genotype (G), environment (E) and genotype-by-environment (G × E) effects on traits that determine the time it takes for saplings to desiccate from stomatal closure to 88% loss of stem hydraulic conductance (time to hydraulic failure, THF). Specifically, we hypothesized that: (i) THF is dependent on a G × E interaction, with longer THF for warm, dry climate populations in response to chronic water deficit treatment compared with cool, wet populations, and (ii) hydraulic and allometric traits explain the observed patterns in THF. Corymbia calophylla saplings from two populations originating from contrasting climates (warm-dry or cool-wet) were grown under well-watered and chronic soil water deficit treatments in large containers. Hydraulic and allometric traits were measured and then saplings were dried-down to critical levels of drought stress to estimate THF. Significant plasticity was detected in the warm-dry population in response to water-deficit, with enhanced drought tolerance compared with the cool-wet population. Projected leaf area and total plant water storage showed treatment variation, and minimum conductance showed significant population differences driving longer THF in trees from warm-dry origins grown in water-limited conditions. Our findings contribute information on intraspecific variation in key drought traits, including hydraulic and allometric determinants of THF. It highlights the need to quantify adaptive capacity in populations of forest trees in climate change-type drought to improve predictions of forest die-back.
Reproductive success and pollinator effectiveness differ in common and rare Persoonia species (Proteaceae)
Publisher: Elsevier BV
Date: 06-2005
Climate change increases global risk to urban forests
Publisher: Springer Science and Business Media LLC
Date: 19-09-2022
Unpacking boxes: Integration of molecular, morphological and ecological approaches reveals extensive patterns of reticulate evolution in box eucalypts
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.YMPEV.2017.01.019
Abstract: Reticulate evolution by hybridization is considered a common process shaping the evolution of many plant species, however, reticulation could also be due to incomplete lineage sorting in bio erse systems. For our study we selected a group of closely related plant taxa with contrasting yet partially overlapping geographic distributions and different population sizes, to distinguish between reticulated patterns due to hybridization and incomplete lineage sorting. We predicted that sympatric or proximal populations of different species are more likely to have gene flow than geographically distant populations of the same widespread species. Furthermore, for species with restricted distributions, and therefore, small effective population sizes, we predicted complete lineage sorting. Eastern grey box eucalypt species (Eucalyptus supraspecies Moluccanae) provide an ideal system to explore patterns of reticulate evolution. They form a erse, recently evolved and phylogenetically undefined group within Eucalyptus, with overlapping morphological features and hybridization in nature. We used a multi-faceted approach, combining analyses of chloroplast and nuclear DNA, as well as seedling morphology, flowering time and ecological spatial differentiation in order to test for species delimitation and reticulate evolution in this group. The multiple layers of results were consistent and suggested a lack of monophyly at different hierarchical levels due to multidirectional gene flow among several species, challenging species delimitation. Chloroplast and nuclear haplotypes were shared among different species in geographic proximity, consistent with hybridization zones. Furthermore, species with restricted distributions appeared better resolved due to lineage sorting in the absence of hybridization. We conclude that a combination of molecular, morphological and ecological approaches is required to disentangle patterns of reticulate evolution in the box eucalypts.
Spatial, climate and ploidy factors drive genomic diversity and resilience in the widespread grass Themeda triandra
Publisher: Wiley
Date: 16-09-2020
DOI: 10.1111/MEC.15614
Desiccation time during drought is highly predictable across species of Eucalyptus from contrasting climates
Publisher: Wiley
Date: 08-08-2019
DOI: 10.1111/NPH.16042
Abstract: Catastrophic failure of the water transport pathway in trees is a principal mechanism of mortality during extreme drought. To be able to predict the probability of mortality at an in idual and landscape scale we need knowledge of the time for plants to reach critical levels of hydraulic failure. We grew plants of eight species of Eucalyptus originating from contrasting climates before allowing a subset to dehydrate. We tested whether a trait-based model of time to plant desiccation t
Aridity drives clinal patterns in leaf traits and responsiveness to precipitation in a broadly distributed Australian tree species
Publisher: Wiley
Date: 17-03-2023
DOI: 10.1002/PEI3.10102
Abstract: Aridity shapes species distributions and plant growth and function worldwide. Yet, plant traits often show complex relationships with aridity, challenging our understanding of aridity as a driver of evolutionary adaptation. We grew nine genotypes of Eucalyptus camaldulensis subsp. camaldulensis sourced from an aridity gradient together in the field for ~650 days under low and high precipitation treatments. Eucalyptus camaldulesis is considered a phreatophyte (deep‐rooted species that utilizes groundwater), so we hypothesized that genotypes from more arid environments would show lower aboveground productivity, higher leaf gas‐exchange rates, and greater tolerance/avoidance of dry surface soils (indicated by lower responsiveness) than genotypes from less arid environments. Aridity predicted genotype responses to precipitation, with more arid genotypes showing lower responsiveness to reduced precipitation and dry surface conditions than less arid genotypes. Under low precipitation, genotype net photosynthesis and stomatal conductance increased with home‐climate aridity. Across treatments, genotype intrinsic water‐use efficiency and osmotic potential declined with increasing aridity while photosynthetic capacity (Rubisco carboxylation and RuBP regeneration) increased with aridity. The observed clinal patterns indicate that E. camaldulensis genotypes from extremely arid environments possess a unique strategy defined by lower responsiveness to dry surface soils, low water‐use efficiency, and high photosynthetic capacity. This strategy could be underpinned by deep rooting and could be adaptive under arid conditions where heat avoidance is critical and water demand is high.
Contrasting heat tolerance of urban trees to extreme temperatures during heatwaves
Publisher: Elsevier BV
Date: 12-2021
Fire severity and the post‐fire soil environment affect seedling regeneration success of the threatened Persoonia hirsuta (Proteaceae)
Publisher: Wiley
Date: 25-06-2022
DOI: 10.1111/AEC.13217
Abstract: Climate change and land management decisions have considerably altered fire regimes globally resulting in increased risks of extreme fire seasons. Fire intensity is one characteristic of fire regime which is projected to increase. However, the magnitude and impact of intense fires on plant habitat and life history characteristics (such as the soil environment or seedling recruitment) remain unclear for many species. The widespread 2019–2020 Black Summer fires across Eastern Australia provided the opportunity to examine the impact of these fires on the short‐term regeneration of the Endangered Persoonia hirsuta (Proteaceae), an obligate seeding (reliant on regeneration from seed following fire) shrub presently threatened by population decline and dieback (plant death from branch and root tips backwards) of an unknown cause. In this study, we used a combination of metrics to estimate fire severity in the field at 22 plots across three fire‐affected populations which we used as a proxy to understand the relative impacts of fire intensity on P. hirsuta regeneration post‐fire. We also recorded the recruitment, growth, dieback and mortality of P. hirsuta seedlings at these plots over 21 months following the fires and examined whether the post‐fire soil environment (carbon, nitrogen and phosphorus) was related to fire severity and seedling responses. Seedling recruitment and growth were variable across sites and showed no relationship to fire severity. However, seedling dieback and mortality were significantly higher among plots exposed to high severity fires. Additionally, characteristics of the post‐fire soil environment varied by fire severity and explained variation in seedling recruitment, growth and dieback. Our work provides important evidence that already vulnerable populations of P. hirsuta may be further threatened by increasing fire severity, highlighting the importance of understanding the effects of fire on habitat and life history characteristics for threatened plants.
Capturing chloroplast variation for molecular ecology studies: a simple next generation sequencing approach applied to a rainforest tree
Publisher: Springer Science and Business Media LLC
Date: 2013
The capacity to cope with climate warming declines from temperate to tropical latitudes in two widely distributed Eucalyptus species
Publisher: Wiley
Date: 06-11-2014
DOI: 10.1111/GCB.12729
Abstract: As rapid climate warming creates a mismatch between forest trees and their home environment, the ability of trees to cope with warming depends on their capacity to physiologically adjust to higher temperatures. In widespread species, in idual trees in cooler home climates are hypothesized to more successfully acclimate to warming than their counterparts in warmer climates that may approach thermal limits. We tested this prediction with a climate‐shift experiment in widely distributed Eucalyptus tereticornis and E. grandis using provenances originating along a ~2500 km latitudinal transect (15.5–38.0°S) in eastern Australia. We grew 21 provenances in conditions approximating summer temperatures at seed origin and warmed temperatures (+3.5 °C) using a series of climate‐controlled glasshouse bays. The effects of +3.5 °C warming strongly depended on home climate. Cool‐origin provenances responded to warming through an increase in photosynthetic capacity and total leaf area, leading to enhanced growth of 20–60%. Warm‐origin provenances, however, responded to warming through a reduction in photosynthetic capacity and total leaf area, leading to reduced growth of approximately 10%. These results suggest that there is predictable intraspecific variation in the capacity of trees to respond to warming cool‐origin taxa are likely to benefit from warming, while warm‐origin taxa may be negatively affected.
Plant–Pollinator Interactions: From Specialization to Generalization
Publisher: Wiley
Date: 10-10-2007
Drought tolerance of Hakea species (Proteaceae) from a range of biomes and life-histories predicted by climatic niche
Publisher: Cold Spring Harbor Laboratory
Date: 02-09-2020
DOI: 10.1101/2020.09.01.276931
Abstract: Extreme drought conditions across the globe are impacting bio ersity with serious implications for the persistence of native species. However, quantitative data on drought tolerance is not available for erse flora to inform conservation management. We quantified physiological drought tolerance in the erse Hakea genus (Proteaceae) to test predictions based on climatic-origin, life history and functional traits. We s led terminal branches of replicate plants of 16 species in a common garden. Xylem cavitation was induced in branches under varying water potential (tension) in a centrifuge and the tension generating 50% loss of conductivity (stem P50) was characterized as a metric for drought tolerance. The same branches were used to estimate plant functional traits, including wood density, specific leaf area, and Huber value (sap flow area to leaf area ratio). There was significant variation in stem P50 among species, which was negatively associated with the species climate-origin (rainfall and aridity). Drought tolerance did not differ among life histories however, a drought avoidance strategy with terete leaf form and greater Huber value may be important for species to colonize and persist in the arid biome. Our findings will contribute to future prediction of species vulnerability to drought and adaptive management under climate change.
Elevated CO2 concentrations reduce C4 cover and decrease diversity of understorey plant community in a Eucalyptus woodland
Publisher: Wiley
Date: 05-03-2018
Closely Related Tree Species with Overlapping Ranges Exhibit Divergent Adaptation to Climate
Publisher: Cold Spring Harbor Laboratory
Date: 10-11-2021
DOI: 10.1101/2021.11.08.467758
Abstract: With global climate change shifting and altering temperature and precipitation regimes, the ability of natural forest stands to persist in their local environments are being challenged. For many taxa, particularly among long lived tree species, the potential to respond is underpinned by genetic and trait ersity and may be limited. We s led 326 and 366 in iduals of two widely distributed and closely-related red gum Eucalyptus species ( E. blakelyi and E. tereticornis ) from across their entire Australian range. We identified putatively adaptive variants associated within genes of key biological processes for both species. We mapped the change of allele frequencies of two hierarchical gene ontology groups shared by both species across geography and climate and predict genomically vulnerable regions under a projected 2070 climate scenario. Regions of potential vulnerability to decline under future climate differed between species and may be applied to guide conservation and restoration strategies. Our study indicated that some populations may contain the adaptive genomic variation necessary for these species to persist through climate change, while others may benefit from the adaptive variation of those populations to enhance resilience.
Elevated temperature is more effective than elevated [CO2] in exposing genotypic variation in Telopea speciosissima growth plasticity: implications for woody plant populations under
Publisher: Wiley
Date: 04-07-2015
DOI: 10.1111/GCB.12990
Abstract: Intraspecific variation in phenotypic plasticity is a critical determinant of plant species capacity to cope with climate change. A long-standing hypothesis states that greater levels of environmental variability will select for genotypes with greater phenotypic plasticity. However, few studies have examined how genotypes of woody species originating from contrasting environments respond to multiple climate change factors. Here, we investigated the main and interactive effects of elevated [CO2 ] (CE ) and elevated temperature (TE ) on growth and physiology of Coastal (warmer, less variable temperature environment) and Upland (cooler, more variable temperature environment) genotypes of an Australian woody species Telopea speciosissima. Both genotypes were positively responsive to CE (35% and 29% increase in whole-plant dry mass and leaf area, respectively), but only the Coastal genotype exhibited positive growth responses to TE . We found that the Coastal genotype exhibited greater growth response to TE (47% and 85% increase in whole-plant dry mass and leaf area, respectively) when compared with the Upland genotype (no change in dry mass or leaf area). No intraspecific variation in physiological plasticity was detected under CE or TE , and the interactive effects of CE and TE on intraspecific variation in phenotypic plasticity were also largely absent. Overall, TE was a more effective climate factor than CE in exposing genotypic variation in our woody species. Our results contradict the paradigm that genotypes from more variable climates will exhibit greater phenotypic plasticity in future climate regimes.
Evidence of recent and continuous speciation in a biodiversity hotspot: a population genetic approach in southern African gladioli (Gladiolus; Iridaceae)
Publisher: Wiley
Date: 23-08-2010
Solving the Problem of Ambiguous Paralogy for Marker Loci: Microsatellite Markers with Diploid Inheritance in Allohexaploid Mercurialis annua (Euphorbiaceae)
Publisher: Oxford University Press (OUP)
Date: 10-03-2010
Abstract: Mercurialis annua is a wind-pollinated annual showing a remarkable sexual-system variation, with hexaploid populations being either monoecious or androdioecious. Hexaploid M. annua is most likely a product of hybridization between diploid M. huetii and tetraploid M. annua therefore, we developed microsatellite loci by isolating simple sequence repeat (SSR) sequences from the diploid progenitor, cross- lification tests in M. huetii/M. annua species complex followed by selection of loci lifying only in M. huetii and hexaploid M. annua, and testing polymorphism in 1 hexaploid population. This protocol resulted in 10 unlinked, polymorphic loci lifying 4-10 alleles per locus. Due to specific lification of the diploid part of the genome originating from M. huetii, these loci produce codominantly scored, diploid data for allohexaploid species, thereby simplifying data collection and subsequent analyses. Sequencing of the hexaploid polymerase chain reaction product for all 10 loci and aligning it with M. huetii SSR library sequence confirmed orthology of the characterized loci. Inheritance tests in 4 hexaploid crosses confirmed diploid Mendelian segregation of the new loci.
Regarding the F‐word: The effects of data filtering on inferred genotype‐environment associations
Publisher: Wiley
Date: 09-03-2021
Abstract: Genotype‐environment association (GEA) methods have become part of the standard landscape genomics toolkit, yet, we know little about how to best filter genotype‐by‐sequencing data to provide robust inferences for environmental adaptation. In many cases, default filtering thresholds for minor allele frequency and missing data are applied regardless of s le size, having unknown impacts on the results, negatively affecting management strategies. Here, we investigate the effects of filtering on GEA results and the potential implications for assessment of adaptation to environment. We use empirical and simulated data sets derived from two widespread tree species to assess the effects of filtering on GEA outputs. Critically, we find that the level of filtering of missing data and minor allele frequency affect the identification of true positives. Even slight adjustments to these thresholds can change the rate of true positive detection. Using conservative thresholds for missing data and minor allele frequency substantially reduces the size of the data set, lessening the power to detect adaptive variants (i.e., simulated true positives) with strong and weak strengths of selection. Regardless, strength of selection was a good predictor for GEA detection, but even some SNPs under strong selection went undetected. False positive rates varied depending on the species and GEA method, and filtering significantly impacted the predictions of adaptive capacity in downstream analyses. We make several recommendations regarding filtering for GEA methods. Ultimately, there is no filtering panacea, but some choices are better than others, depending on the study system, availability of genomic resources, and desired objectives.
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.
Evidence for clonality, breeding system, genetic diversity and genetic structure in large and small populations of Melaleuca deanei (Myrtaceae)
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/BT18148
Abstract: Melaleuca deanei F.Muell. is a rare, serotinous shrub with a naturally restricted distribution centred over the sandstone ridges around Sydney. Sexual reproduction and seedling recruitment occur rarely, and plants appear to spread and persist largely by clonal root suckering. A potentially outcrossing breeding system, combined with extensive clonality, place M. deanei at a high risk of reproductive failure. Knowledge of the extent of its clonality and breeding system, and an understanding of the distribution and abundance of genetic ersity within and among its populations, will assist conservation management. The present study reports on the extent of clonality, breeding system, levels of genetic ersity, and population differentiation within small, medium and large populations of M. deanei from the northern and southern distribution regions. Multiple stems were found to comprise single genets up to ~10 m diameter on the ground and molecular evidence points to an outcrossing breeding system. Genetic ersity was positively correlated with population size and significant genetic differentiation was shown between northern and southern regions using clustering analyses. Recommendations for in situ and ex situ conservation management based on these results are provided.
Recent phylogeographic structure in a widespread ‘weedy’ Neotropical tree species, Cordia alliodora (Boraginaceae)
Publisher: Wiley
Date: 21-06-2012
Vulnerability to xylem cavitation of Hakea species (Proteaceae) from a range of biomes and life histories predicted by climatic niche
Publisher: Oxford University Press (OUP)
Date: 19-02-2021
DOI: 10.1093/AOB/MCAB020
Abstract: Extreme drought conditions across the globe are impacting bio ersity, with serious implications for the persistence of native species. However, quantitative data on physiological tolerance are not available for erse flora to inform conservation management. We quantified physiological resistance to cavitation in the erse Hakea genus (Proteaceae) to test predictions based on climatic origin, life history and functional traits. We s led terminal branches of replicate plants of 16 species in a common garden. Xylem cavitation was induced in branches under varying water potentials (tension) in a centrifuge, and the tension generating 50 % loss of conductivity (stem P50) was characterized as a metric for cavitation resistance. The same branches were used to estimate plant functional traits, including wood density, specific leaf area and Huber value (sap flow area to leaf area ratio). There was significant variation in stem P50 among species, which was negatively associated with the species climate origin (rainfall and aridity). Cavitation resistance did not differ among life histories however, a drought avoidance strategy with terete leaf form and greater Huber value may be important for species to colonize and persist in the arid biome. This study highlights climate (rainfall and aridity), rather than life history and functional traits, as the key predictor of variation in cavitation resistance (stem P50). Rainfall for species origin was the best predictor of cavitation resistance, explaining variation in stem P50, which appears to be a major determinant of species distribution. This study also indicates that stem P50 is an adaptive trait, genetically determined, and hence reliable and robust for predicting species vulnerability to climate change. Our findings will contribute to future prediction of species vulnerability to drought and adaptive management under climate change.
Isolation and characterization of 11 microsatellite markers from Sagittaria latifolia (Alismataceae)
Publisher: Wiley
Date: 12-02-2009
DOI: 10.1111/J.1755-0998.2008.02400.X
Abstract: We developed 11 microsatellite loci for Sagittaria latifolia, an aquatic plant common to wetlands of North America. From an (AG)-enriched library, we identified 66 unique microsatellite sequences for which primers could be designed. Twenty-two loci reliably lified a clear single band of expected size, and 11 loci were scoreable and polymorphic. For these 11 loci, we genotyped a monoecious and a dioecious population, yielding four to 14 alleles per locus. Three loci exhibited significant linkage disequilibrium leaving eight independent variable loci. Eight loci also lified in four other Sagittaria species. These microsatellite loci will be useful to compare genetic structure among monoecious and dioecious populations of S. latifolia.
Impacts of recent climate change on terrestrial flora and fauna: Some emerging Australian examples
Publisher: Wiley
Date: 20-11-2019
DOI: 10.1111/AEC.12674
The fate of carbon in a mature forest under carbon dioxide enrichment
Publisher: Springer Science and Business Media LLC
Date: 08-04-2020
Are Seed Dispersal and Predation in Fire‐Sensitive Persoonia Species (Proteaceae) Associated with Rarity?
Publisher: University of Chicago Press
Date: 11-2006
DOI: 10.1086/507316
The fate of carbon in a mature forest under carbon dioxide enrichment
Publisher: Cold Spring Harbor Laboratory
Date: 11-07-2019
DOI: 10.1101/696898
Abstract: Atmospheric carbon dioxide enrichment (eCO 2 ) can enhance plant carbon uptake and growth 1,2,3,4,5 , thereby providing an important negative feedback to climate change by slowing the rate of increase of the atmospheric CO 2 concentration 6 . While evidence gathered from young aggrading forests has generally indicated a strong CO 2 fertilization effect on biomass growth 3,4,5 , it is unclear whether mature forests respond to eCO 2 in a similar way. In mature trees and forest stands 7,8,9,10 , photosynthetic uptake has been found to increase under eCO 2 without any apparent accompanying growth response, leaving an open question about the fate of additional carbon fixed under eCO 2 4, 5, 7,8,9,10,11 . Here, using data from the first ecosystem-scale Free-Air CO 2 Enrichment (FACE) experiment in a mature forest, we constructed a comprehensive ecosystem carbon budget to track the fate of carbon as the forest responds to four years of eCO 2 exposure. We show that, although the eCO 2 treatment of ambient +150 ppm (+38%) induced a 12% (+247 gCm -2 yr -1 ) increase in carbon uptake through gross primary production, this additional carbon uptake did not lead to increased carbon sequestration at the ecosystem level. Instead, the majority of the extra carbon was emitted back into the atmosphere via several respiratory fluxes, with increased soil respiration alone contributing ∼50% of the total uptake surplus. Our results call into question the predominant thinking that the capacity of forests to act as carbon sinks will be generally enhanced under eCO 2 , and challenge the efficacy of climate mitigation strategies that rely on CO 2 fertilization as a driver of increased carbon sinks in standing forests and afforestation projects.
Adaptive variation for growth and resistance to a novel pathogen along climatic gradients in a foundation tree
Publisher: Wiley
Date: 15-04-2019
DOI: 10.1111/EVA.12796
Pollinator behaviour and plant speciation: can assortative mating and disruptive selection maintain distinct floral morphs in sympatry?
Publisher: Wiley
Date: 25-08-2010
DOI: 10.1111/J.1469-8137.2010.03438.X
Abstract: Featured paper: See Commentary p303
Leaf trait variation is similar among genotypes of Eucalyptus camaldulensis from differing climates and arises in plastic responses to the seasons rather than water avai
Publisher: Wiley
Date: 06-05-2020
DOI: 10.1111/NPH.16579
Clonality and inbreeding amplifies genetic isolation and mate limitation in a rare montane woody plant (Persoonia hindii; Proteaceae)
Publisher: Cold Spring Harbor Laboratory
Date: 27-05-2020
DOI: 10.1101/2020.05.25.114231
Abstract: Small populations have genetic attributes that make them prone to extinction, including low effective population size ( Ne ), increased levels of inbreeding, and negative impacts from genetic drift. Some small populations are also clonal with low levels of genetic ersity, restricted seed dispersal, and high levels of genetic structure. Together, these attributes make species with small, isolated, clonal populations unlikely to persist under environmental change. We investigated an endangered woody plant species ( Persoonia hindii ) in eastern Australia to answer key questions about genetic differentiation, migration rates, population sizes, size of clones, mating system and Ne . We identified 587 single nucleotide polymorphisms. Of the 88 in idual stems collected from 15 sites across the entire distribution of P. hindii , we identified 30 multi-locus genotypes (MLG). Additional fine-scale genotyping of two sites (49 and 47 stems) detected a dominant genet within each site occupying a minimum area of 20 m 2 . Global population differentiation was high ( F ST 0.22) with very low migration rates (0.048 - 0.064). We identified some population structure with variable site pairwise differentiation (0.015 - 0.32) with no detectable spatial autocorrelation. Species wide inbreeding coefficient was 0.42 ( F IT ), supporting the direct estimate of 82% selfing. Estimated Ne was extremely small (15), indicating that genetic drift may be reducing genetic ersity and increasing genetic load through fixation of deleterious alleles. Clonality and inbreeding combined with negligible gene flow suggests limited adaptive capacity to respond to climate challenges. Genetic rescue, through assisted gene migration and experimental translocations, would enhance the persistence of natural populations.
Drought tolerance traits do not vary across sites differing in water availability in Banksia serrata (Proteaceae)
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/FP18238
Abstract: Interspecific variation in plant hydraulic traits plays a major role in shaping species distributions across climates, yet variation within species is poorly understood. Here we report on intraspecific variation of hydraulic traits in Banksia serrata (L.f.) s led from three sites characterised by contrasting climates (warm-wet, warm-dry and cool-wet). Hydraulic characteristics including vulnerability to embolism, hydraulic conductance, pressure-volume traits and key morphological traits were measured. Vulnerability to embolism in leaf and stem, defined by the water potential inducing 50 and 88% loss of hydraulic conductivity (P50 and P88 respectively), did not differ across sites. However, plants from the warm-dry environment exhibited higher stem conductivity (Ks) than the cool-wet environment. Leaf turgor loss point (TLP) did not vary among sites, but warm-dry site plants showed lower leaf capacitance (C*FT) and higher modulus of elasticity (ε) than the other two sites. Plants from the cool-wet site had lower specific leaf area (SLA) and plants from the warm-dry site had lower sapwood density (WD). Overall, key hydraulic traits were generally conserved across populations despite differences in mean site water availability, and the safety-efficiency trade-off was absent in this species. These results suggest that B. serrata has limited ability to adjust hydraulic architecture in response to environmental change and thus may be susceptible to climate change-type drought stress.
Isolation and characterization of microsatellite markers for the waratah, Telopea speciosissima (Proteaceae)
Publisher: Wiley
Date: 27-03-2006
Spatial, climate, and ploidy factors drive genomic diversity and resilience in the widespread grass Themeda triandra
Publisher: Cold Spring Harbor Laboratory
Date: 04-12-2019
DOI: 10.1101/864298
Abstract: Fragmented grassland ecosystems, and the species that shape them, are under immense pressure. Restoration and management strategies should include genetic ersity and adaptive capacity to improve success but these data are generally unavailable. Therefore, we use the foundational grass, Themeda triandra , to test how spatial, environmental, and ploidy factors shape patterns of genetic variation. We used reduced-representation genome sequencing on 487 s les from 52 locations to answer fundamental questions about how the distribution of genomic ersity and ploidy polymorphism supports adaptation to harsher climates. We explicitly quantified isolation-by-distance (IBD), isolation-by-environment (IBE), and predicted population genomic vulnerability in 2070. We found that a majority (54%) of the genomic variation could be attributed to IBD, while 22% of the genomic variation could be explained by four climate variables showing IBE. Results indicate that heterogeneous patterns of vulnerability across populations are due to genetic variation, multiple climate factors, and ploidy polymorphism, which lessened genomic vulnerability in the most susceptible populations. These results indicate that restoration and management of T. triandra should incorporate knowledge of genomic ersity and ploidy polymorphisms to increase the likelihood of population persistence and restoration success in areas that will become hotter and more arid.
The comparative study of range-wide genetic structure across related, co-distributed rainforest trees reveals contrasting evolutionary histories
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/BT06195
Abstract: Australia’s rainforests exhibit high taxonomic ersity and endemism, yet relatively little is known about patterns of genetic ersity across the flora. Habitat contractions caused by the aridification of the continent and the recent glacial cycles have left discrete genetic signatures on modern-day populations, with the nature of between-population differentiation likely to be influenced by a range of ecological and environmental factors. We used microsatellites to examine range-wide population genetic structure in two congeneric rainforest trees, Elaeocarpus angustifolius and E. largiflorens (Elaeocarpaceae), with similar habitat preference and dispersal potential. The aim was to investigate the relationships between genetic structure, geographic disjunction and morphological differentiation and attempt to clarify the likely evolutionary processes responsible for the observed patterns. We found substantial differences in the amount and type of genetic differentiation within the two co-distributed species. While Elaeocarpus largiflorens revealed an abrupt genetic disjunction front between two subspecies separated by a recognised biogeographic barrier (the Black Mountain Corridor), E. angustifolius showed lower genetic differentiation across a much wider geographic area. Our findings suggest that biogeographic features have different impacts on related species, and that generalisations on evolutionary patterns can be untenable without considering a range of factors. Also, on the basis of the available molecular data, a likely hypothesis is of pre-Pleistocene differentiation followed by reinforcement of differentiation patterns during recent glacial cycles (further studies are needed to conclusively date ergence).
Assessing the vulnerability of Australia’s urban forests to climate extremes
Publisher: Wiley
Date: 11-08-2019
DOI: 10.1002/PPP3.10064
Applications of Molecular Markers in Plant Conservation
Publisher: Wiley
Date: 10-10-2012
The search for loci under selection: trends, biases and progress
Publisher: Wiley
Date: 03-2018
DOI: 10.1111/MEC.14549
Abstract: Detecting genetic variants under selection using F
Does threatened species listing status predict climate change risk? A case study with Australian Persoonia (Proteaceae) species
Publisher: Elsevier BV
Date: 11-2021
Functional adaptations and trait plasticity of urban trees along a climatic gradient
Publisher: Elsevier BV
Date: 10-2020
Genomic constraints to drought adaptation
Publisher: Cold Spring Harbor Laboratory
Date: 08-08-2021
DOI: 10.1101/2021.08.07.455511
Abstract: Global shifts in climate and precipitation patterns are altering the ersity and structure of forests. The ability for species to adapt is especially difficult for long lived foundation species with unknown genetic and trait ersity. We harnessed genomic, physiological, and climate data to determine adaptation constraints. We used denovo assembly and 6.5 million genomic variants with drought related traits from 432 in iduals sourced from across the complete range of the foundation tree species Corymbia calophylla . We found genomic variants determining traits predominantly in gene regulatory regions. The ability for populations to adapt was limited by within population genetic ersity associated with traits, and epistatic interactions within traits and pleiotropic interactions among traits. Nevertheless, we could accurately predict adaptive traits using genomic and climate data to guide reforestation. Our study indicated that some populations may contain variation sufficient for the species to adapt to the effects of drought, while other populations will need increased variability from those sources.
Breeding system and population genetics of the vulnerable plant Dillwynia tenuifolia (Fabaceae)
Publisher: Wiley
Date: 06-2002
Remnant Pachira quinata pasture trees have greater opportunities to self and suffer reduced reproductive success due to inbreeding depression
Publisher: Springer Science and Business Media LLC
Date: 21-08-2013
DOI: 10.1038/HDY.2013.73
Isolation and characterization of polymorphic microsatellite loci from Tetratheca ericifolia (Elaeocarpaceae)
Publisher: Wiley
Date: 28-06-2008
DOI: 10.1111/J.1755-0998.2008.02093.X
Abstract: We identified 11 informative microsatellite loci in Tetratheca ericifolia from an (AG)(n) -enriched library. Using these loci on 32 in iduals from two populations (16 in iduals from each), we detected an average of 11.3 alleles per locus (range of five to 21, average expected heterozygosity of 0.728), of which 56% were unique to one population or the other. All loci were lifiable in seven to 12 of a further 12 species of Tetratheca under the same reaction conditions. The markers will be useful tools for evolutionary studies of this Australian endemic group.
Bioclimatic transect networks: Powerful observatories of ecological change
Publisher: Wiley
Date: 19-05-2017
DOI: 10.1002/ECE3.2995
Aquaporins in the wild: natural genetic diversity and selective pressure in the PIP gene family in five Neotropical tree species
Publisher: Springer Science and Business Media LLC
Date: 29-06-2010
Abstract: Tropical trees undergo severe stress through seasonal drought and flooding, and the ability of these species to respond may be a major factor in their survival in tropical ecosystems, particularly in relation to global climate change. Aquaporins are involved in the regulation of water flow and have been shown to be involved in drought response they may therefore play a major adaptive role in these species. We describe genetic ersity in the PIP sub-family of the widespread gene family of Aquaporins in five Neotropical tree species covering four botanical families. PIP Aquaporin subfamily genes were isolated, and their DNA sequence polymorphisms characterised in natural populations. Sequence data were analysed with statistical tests of standard neutral equilibrium and demographic scenarios simulated to compare with the observed results. Chloroplast SSRs were also used to test demographic transitions. Most gene fragments are highly polymorphic and display signatures of balancing selection or bottlenecks chloroplast SSR markers have significant statistics that do not conform to expectations for population bottlenecks. Although not incompatible with a purely demographic scenario, the combination of all tests tends to favour a selective interpretation of extant gene ersity. Tropical tree PIP genes may generally undergo balancing selection, which may maintain high levels of genetic ersity at these loci. Genetic variation at PIP genes may represent a response to variable environmental conditions.
Characterisation of thirteen polymorphic microsatellite markers for the red sea urchin Heliocidaris tuberculata (Lamarck, 1816) developed using a 454-sequencing approach
Publisher: Springer Science and Business Media LLC
Date: 22-10-2013
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