ORCID Profile
0000-0001-5821-9206
Current Organisations
University of Western Australia
,
Botanic Gardens and Parks Authority
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Public Library of Science (PLoS)
Date: 09-06-2021
DOI: 10.1371/JOURNAL.PONE.0242035
Abstract: To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra , Microlaena stipoides , and Rytidosperma geniculatum . Salicylic acid (SA, 0.1mM) was delivered to seeds via imbibition and seed encrusting. The effects of SA on seed germination were examined under controlled water-limited conditions (drought resilience) in laboratory setting and on seed germination, seedling emergence, seedling growth and plant survival in field conditions. Salicylic acid did not impact germination under water stress in controlled laboratory conditions and did not affect seedling emergence in the field. However, seedling survival and growth were improved in plants grown from SA treated seeds (imbibed and encrusted) under field conditions. When SA delivery methods of imbibing and coating were compared, there was no significant difference in survival and growth, showing that seed coating has potential to deliver SA. Effect of intraspecific competition as a result of seedling density was also considered. Seedling survival over the dry summer season was more than double at low seedling density (40 plants/m 2 ) compared to high seedling density (380 plants/m 2 ). Overall, adjustment of seeding rate according to expected emergence combined with the use of salicylic acid via coating could improve seed use efficiency in seed-based restoration.
Publisher: Wiley
Date: 12-08-2022
DOI: 10.1111/REC.13503
Abstract: Mining activity causes major changes in site topography, soil physical and chemical properties, hydrology, and biological assemblages. Reassembling plant communities in these highly altered environments is dependent on interactions between environmental drivers and management intervention techniques through time, yet the long‐term effects of these interactions have rarely been quantified. This study examined a 19‐year‐old, postmining woodland restoration chronosequence in southwest Australia to understand plant community compositional development in postmine restoration sites. We tested the effects of environmental drivers (rainfall regimes, site aspect, slope) and management intervention techniques (substrate ripping and material properties) in terms of four restoration criteria: species richness, plant density, vegetation cover, and compositional similarity to reference sites. Irrespective of environmental drivers or management intervention techniques, vegetation cover increased through time, while plant density and species richness declined. Bray–Curtis similarity to reference communities remained unchanged. Within these trends, ripping and first‐year rainfall significantly affected restoration criteria outcomes species richness and plant density were greatest when rainfall in the first winter immediately following site restoration was low but followed by a high summer rainfall. The most effective ripping depth was dependent on rainfall, deep‐ripped sites performed best when rainfall was high, and nonripped sites performed best under low‐mean rainfall conditions. Measured restoration criteria had not reached the levels of the target reference community after 19 years, which may be attributable to the still‐developing vegetation structure. This emphasizes the importance of assessing postmining restoration outcomes over longer time frames ( years) with implications for determining appropriate, time‐dependent completion criteria.
Publisher: Oxford University Press (OUP)
Date: 03-04-2012
DOI: 10.1093/AOB/MCS067
Publisher: Springer Science and Business Media LLC
Date: 18-05-2014
Publisher: Oxford University Press (OUP)
Date: 27-12-2018
DOI: 10.1093/AOB/MCX158
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/BT11170
Abstract: The smoke-derived chemical karrikinolide commonly triggers seeds in the Brassicaceae, Solanaceae and Asteraceae families to germinate, yet species in the Poaceae – another major understorey and weed family – have responded to the chemical with mixed results. This study aimed to understand why some grass species respond to karrikinolide while others do not. Using a field-based seed-burial trial, dose-response experiment, and stratification experiment, we investigated whether karrikinolide could alleviate dormancy and trigger seeds to germinate for seven global agronomic weeds: Avena fatua L., Lolium rigidum Gaudin, Eragrostis curvula (Schrad.) Nees, Phalaris minor Retz., Hordeum glaucum Steud., Ehrharta calycina Sm. and Bromus diandrus Roth. Seeds of A. fatua were consistently stimulated to germinate with karrikinolide in all experiments, whether seeds were freshly collected or dormancy had been partially alleviated. In contrast, seeds of L. rigidum failed to respond to karrikinolide when the seeds were fresh, after-ripened in the laboratory, and even during natural dormancy loss in the field. Interestingly, although karrikinolide did not stimulate freshly collected E. curvula seeds to germinate, it hastened dormancy loss when applied during stratification. These findings are helpful for understanding the responses of grass species following fire. They also contribute to a growing body of research aimed at using karrikinolide as a tool for triggering uniform germination of seeds for enhancing restoration efforts and depleting the weed seed bank.
Publisher: Springer Science and Business Media LLC
Date: 26-09-2017
Publisher: Springer Science and Business Media LLC
Date: 08-05-2012
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/AR06031
Abstract: Saltbush (Atriplex) species are widely grown in Australia as saltland pastures. Direct seeding practices for saltbush currently result in asynchronous and unreliable seedling establishment (5% successful establishment is not uncommon from field-sown seed). In part this may stem from a limited understanding of Atriplex seed germination requirements. This paper presents findings with 3 Atriplex species, A. amnicola (Paul G. Wilson.), A. nummularia (Lindl.), and A. undulata (D. Dietr), each of which differs in germination characteristics. For A. amnicola, the presence of light (and artificial substitution of light by 1000 ppm gibberellic acid) improved germination under controlled conditions and resulted in a 4-fold increase (70% total emergence) in field emergence of seedlings. For A. undulata, removing bracteoles increased germination under controlled conditions (~15%), with a 1.5-fold improvement in field seedling emergence (55% final emergence) however, seed priming or gibberellic acid application had no significant effect. In contrast, for A. nummularia, bracteole removal and light had minor positive effects on germination under controlled conditions, but this did not translate into improved emergence in soil or in the field. Under –0.5 MPa NaCl stress, application of gibberellic acid, salicylic acid, or kinetin to the germination medium significantly increased the final germination percentage of A. amnicola seeds (58, 16, and 14%, respectively) and improved the rate at which seeds germinated. All plant signalling compounds significantly increased final germination percentage and germination rate of A. undulata, albeit with a % increase at –0.5 MPa NaCl. Priming seeds with plant signalling compounds had similar effects on seed germination under low water potentials compared to direct treatment of the germination media. The effects of seed priming on Atriplex seedling emergence from saline soils varied among species. Priming with water significantly increased emergence percentage of A. amnicola but had no effect on A. nummularia and A. undulata. Gibberellic acid improved A. amnicola germination parameters only, whereas salicylic acid and kinetin improved the rate of emergence in all 3 species at various levels of salinity. This study suggests that a basic understanding of seed dormancy and germination requirements has the potential to substantially improve field emergence of saltbush species.
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/BT17155
Abstract: Translocation of threatened species is challenging in semiarid environments, especially when seeds are the principal means of in situ establishment. Worldwide, the overall success of translocations using seeds is highly variable and generally unpredictable. Most seed-based translocations are embarked upon with limited understanding of the species’ seed biology or the nuances of the local abiotic environment in which to guide restoration approaches. For instance, within Australia just 14% of threatened species translocations use directly sown seeds and consequently, to improve the chances of restoration success, both the seed biology and the influence of the abiotic environment need to be adequately understood. We investigated these aspects in Ricinocarpos brevis R.J.F.Hend. & Mollemans – a short-range Banded Ironstone endemic – by focusing on a series of laboratory and field experiments to understand the key drivers of dormancy alleviation and germination promotion, as well as in-situ conditions of natural and recipient translocation sites. Fresh seeds were found to have high viability, fully developed linear embryos and possess physiological dormancy, with enhanced germination when exposed to smoke water, karrikinolide (KAR1) and gibberellic acid (GA3). Under laboratory conditions, seeds germinated over a range of temperatures (15−30°C), but germination was suppressed by light and highly sensitive to water stress. Seeds had reduced germination when sown on the soil surface, but could emerge from up to 13 cm in depth. Under field conditions, in-situ emergence was %. Using in-situ emergence results, soil loggers and rainfall data, we developed a model of the recruitment bottlenecks faced by this species under in-situ conditions, an approach that provides useful insights to assist future translocations. Understanding seed biology and seed ecology enables better insights into the principal bottlenecks restricting in-situ emergence and consequently restoration success, leading to the development of more effective approaches for conserving other threatened flora in future.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 06-2017
Publisher: Wiley
Date: 23-09-2022
DOI: 10.1111/REC.13784
Abstract: Extruded pellets containing activated carbon (AC) can be used to sow native seeds while simultaneously applying herbicide to control invasive species. Incorporating AC in pellets has been demonstrated to protect native seeds however, there may be unintended detrimental impacts to seedling emergence. We aimed to optimize seed position within pellets to maximize emergence and survival of the perennial shrub Jacksonia furcellata . Seeds were positioned at 2 mm (top), 6 mm (middle), and 12 mm (bottom) within pellets (with or without AC), sown on or below the soil surface, and compared to non‐pelleted seeds sown under the soil surface in the equivalent positions (2, 6, and 12 mm depth). Trays were treated with a pre‐emergent herbicide (Simazine) or left unsprayed. Emergence (without herbicide) was significantly higher from seeds positioned at the bottom of pellets without AC sown on the soil surface (70%), compared to non‐pelleted seeds sown at the bottom (12 mm below the soil surface 57%). However, emergence was inhibited when seeds were positioned in the middle (6 mm) of pellets with AC (32%). When treated with Simazine, survival was highest from seeds positioned at the bottom of pellets with AC (60%), compared to pellets without AC (15%) and non‐pelleted seeds sown at the bottom (12 mm below the soil surface 15%). Jacksonia furcellata seeds positioned at the bottom of pellets, sown on the soil surface, shows promise to minimize negative impacts to emergence, and maximize herbicide protection. Further testing with additional species is required to refine pellet production (e.g. recipe, extrusion, and shape) for optimal emergence.
Publisher: Springer Science and Business Media LLC
Date: 08-08-2007
Publisher: Elsevier BV
Date: 10-2021
Publisher: Wiley
Date: 30-08-2019
DOI: 10.1111/PLB.12885
Abstract: Grasslands across the globe are undergoing expansive degradation due to human impacts and climate change. If restoration of degraded native grassland is to be achieved at the scale now required, cost-effective means for seed-based establishment of grass species is crucial. However, grass seeds present numerous challenges associated with handling and germination performance that must be overcome to improve the efficiency of seeding. Previous research has demonstrated that complete removal of the palea and lemma (husk) maximises germination performance, hence we investigated the effects of complete husk removal on seed handling and germination of four temperate Australian grass species. Three techniques were tested to remove the husk - manual cleaning, flaming or acid digestion (the latter two followed by a manual cleaning step) these techniques were refined and adapted to the selected species, and germination responses were compared. The complete removal of the husk improved seed handling and sowability for all species. Germination was improved in Microlaena stipoides by 19% and in Rytidosperma geniculatum by 11%. Of the husk removal methods tested, flaming was detrimental to seed germination and fatal for one species (R. geniculatum). Compared to manual cleaning, sulphuric acid improved the overall efficacy of the cleaning procedure and increased germination speed (T50) in Austrostipa scabra, Chloris truncata and M. stipoides, and improved final germination in R. geniculatum by 13%. The seed processing methods developed and tested in the present study can be applied to grass species that present similar handling and germination performance impediments. These and other technological developments (seed coating and precision sowing) will facilitate more efficient grassland restoration at large scale.
Publisher: Springer Science and Business Media LLC
Date: 20-02-2016
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/FP13366
Abstract: Climate change is increasing the frequency and intensity of drought, and seedling response to a recurrent pattern of drought stress is necessary to understand vegetation establishment patterns in particularly for ecological restoration and conservation projects. A controlled environment study investigated seedling physiological response of framework Mediterranean tree species to simulated successive droughts. Six-month-old seedlings were grown in 1.0 m tall pots to emulate deep soil profiles and subjected to a well watered treatment and a drought treatment consisting of an initial 60 day drought (water withholding), followed by 120 days of re-watering and a subsequent 60 day drought. Soil water access, soil water content, maximum root depth and xylem water potential were assessed through successive harvests. To assess seedling response to multiple droughts, gas-exchange and chlorophyll fluorescence measurements were taken every 15 days after each drought, and multiple times throughout re-watering. No seedling mortality was observed during the initial drought, whereas 100% mortality of all species occurred within 48 days of the second drought. Seedling gas exchange and water potential decreased with decreasing water availability but was dependent on the isohydric or anisohydric behaviour of in idual species. An absence of sustained photoprotection during the second drought phase heightened photodamage to foliar tissues resulting in a more rapid decrease of gs and leaf water potential. Therefore, biphasic drought proved detrimental to seedling establishment by reducing physiological resilience, highlighting the severity of future climate change predictions towards the regeneration capacity of Mediterranean ecosystems.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.SCITOTENV.2018.09.171
Abstract: The present study aimed to characterize key physico-chemical and mineralogical attributes of magnetite iron (Fe) ore tailings to identify potential constraints limiting in situ soil formation and direct phytostabilization. Tailings of different age, together with undisturbed local native soils, were s led from a magnetite mine in Western Australia. Tailings were extremely alkaline (pH > 9.0), with a lack of water stable aggregate and organic matter, and contained abundant primary minerals including mica (e.g., biotite), with low specific surface area (N
Publisher: Springer Science and Business Media LLC
Date: 03-04-2017
DOI: 10.1038/S41598-017-00650-6
Abstract: Mining of mineral resources produces substantial volumes of crushed rock based wastes that are characterised by poor physical structure and hydrology, unstable geochemistry and potentially toxic chemical conditions. Recycling of these substrates is desirable and can be achieved by blending waste with native soil to form a ‘novel substrate’ which may be used in future landscape restoration. However, these post-mining substrate based ‘soils’ are likely to contain significant abiotic constraints for both plant and microbial growth. Effective use of these novel substrates for ecosystem restoration will depend on the efficacy of stored topsoil as a potential microbial inoculum as well as the subsequent generation of key microbial soil functions originally apparent in local pristine sites. Here, using both marker gene and shotgun metagenome sequencing, we show that topsoil storage and the blending of soil and waste substrates to form planting substrates gives rise to variable bacterial and archaeal phylogenetic composition but a high degree of metabolic conservation at the community metagenome level. Our data indicates that whilst low phylogenetic conservation is apparent across substrate blends we observe high functional redundancy in relation to key soil microbial pathways, allowing the potential for functional recovery of key belowground pathways under targeted management.
Publisher: Wiley
Date: 17-02-2022
DOI: 10.1111/REC.13616
Abstract: The incorporation of conservation physiology into environmental management, particularly ecological restoration, is underutilized, despite the capacity of such approaches to discern how populations respond to the challenges of unpredictable and potentially inhospitable environments. We explore several ex les where detailed mechanistic understanding of the physiological constraints of keystone and foundational species, ecological service providers such as insect pollinators, and species of conservation concern has been used to optimize the return of these species to landscapes following the cessation of mineral extraction. Using such data can optimize the rapid return of functioning ecosystems during restoration or increase the conservation value of restoration by returning insurance populations of threatened species. Integrating this level of mechanistic understanding with fine‐resolution spatial data in the form of biophysical modeling can help plan recovery and identify targets that can subsequently be used in assessing restoration success, particularly in situations that require substantial investment over long periods, such as post‐mining restoration. There is growing recognition of the valuable insights offered by conservation physiology to broader practice and policy development, and there have been substantial technical developments in conservation physiology leading up to and into the twenty‐first century as a result. The global challenge facing restoration ecology has, however, also grown in that time. Rapidly and efficiently meeting ambitious global restoration objectives will require a targeted approach, and we suggest that the application of physiological data will be most strategic for rare species, keystone species, and ecosystem service providers more broadly.
Publisher: Springer Science and Business Media LLC
Date: 28-09-2006
Publisher: Wiley
Date: 10-2020
Abstract: 1. Globally, soil water repellency is a major constraint to plant establishment, restricting water infiltration and moisture retention in the seed zone which results in poor germination and seedling emergence. 2. To address this problem within an ecosystem restoration context, we investigated the use of a surfactant in extruded seed pellets to improve native plant recruitment in water‐repellent topsoils of two proteaceous woodland species, Banksia menziesii R.Br (glasshouse trial) and Lambertia inermis R.Br (field trial). In this two‐part study, we first examined B. menziesii seedling performance in detail under glasshouse conditions for differences in survival between the extruded pelleting formulations after an induced drought at 12 weeks. 3. We demonstrated that there was no difference in seedling emergence amongst control seed and pellet treatments in B. menziesii . Initially, B. menziesii seedlings emerged faster in the control treatment (non‐pelleted control seeds) and had greater initial plant growth (leaf and root production), however by Week 12, seedlings generated from pellets were not significantly different from the control seeds and pellets + surfactant had the greatest number of leaf establishment. 4. Survival after drought of B. menziesii seedlings ranged from 14 to 31 days with pellet + surfactant surviving approximately 2.6 days (11.8%) longer than the control seeds. For the second species, L. inermis , seedling emergence under field conditions was approximately 24% greater in seedlings derived from extruded pellets however, there was no difference in overall survival due to post‐emergence predation. 5. This study provides a proof of concept that seedling emergence in water‐repellent soils can be enhanced with extruded pellets containing surfactants. Our demonstration under in situ and ex situ conditions confirms the prospective use of seed enhancement technologies with future development and field‐testing warranted.
Publisher: Wiley
Date: 16-10-2013
Publisher: Springer Science and Business Media LLC
Date: 14-03-2021
Publisher: Springer Science and Business Media LLC
Date: 2017
Publisher: Wiley
Date: 28-10-2022
DOI: 10.1111/REC.13571
Abstract: As human activities destroy and degrade the world's ecosystems at unprecedented scales, there is a growing need for evidence‐based methods for ecological restoration if we are to preserve bio ersity and ecosystem services. Mining represents one of the most severe anthropogenic disturbances, often necessitating intensive intervention to restore the most basic attributes of native ecosystems. Despite ex les of successful mine‐site restoration, re‐establishing native vegetation in these degraded landscapes remains a significant challenge. Plant ecophysiology—the study of the interactions between plants and the environment—can provide a useful framework for evaluating and guiding mine‐site restoration. By understanding the physiological mechanisms that allow plants to establish and persist in these highly disturbed environments, practitioners may be able to improve restoration outcomes. Specifically, methods in plant ecophysiology can inform site preparation and the selection of plant material for restoration projects, aid in monitoring restoration progress by providing additional insight into plant performance, and ultimately improve our ability to predict restoration trajectories. Here, we review the challenges and benefits of integrating an ecophysiological perspective to mine‐site restoration in Western Australia, a global hotspot of bio ersity and mining operations. Using case studies and ex les from the region's erse ecosystems, we illustrate how an ecophysiological approach can guide the restoration of some of the world's most severely disturbed landscapes. With careful selection of study species and traits and consideration of the specific environmental conditions and stressors within a site, the restoration ecophysiology framework outlined here has the potential to inform restoration strategies across ecosystems.
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/BT13181
Abstract: Limited success of restoring framework banksia-woodland species has been attributed to the failure of seedlings to establish deep root systems before the onset of the summer drought. The present glasshouse study investigated how optimising nutrient application during nursery production may increase new-root production after outplanting. Two experimental streams were established to (1) optimise nutrient application rates during nursery production and (2) utilise nutrient-loading techniques to improve root production of Banksia menziesii R.Br., Banksia attenuata R.Br. and Eucalyptus todtiana F.Muell after outplanting. Optimal nutrient-application rates were determined by measuring plant growth and internal nutrient responses to eight application levels of slow-release fertiliser (0–18 kg m–3, nitrogen (N) : phosphorus (P) : potassium (K) = 17 : 1.6 : 8.7). Nutrient-loading treatments utilised seedlings that had been grown under common industry fertiliser conditions (3 kg m–3 native Osmocote, N : P : K = 17 : 1.6 : 8.7) supplied with ‘low’ or ‘high’ loading doses of liquid Thrive continuously over 6 weeks, immediately before outplanting. Seedlings from both experiments were then outplanted to 1-m-deep poly-pipe tubes containing habitat soil. After 12 weeks, plants were harvested and new-root production and shoot growth were measured. Optimal concentrations of slow-release fertiliser for maximum outplanting success as indicated by increased root investment (root : shoot ratio and new-root production) were 8–12 kg m–3 for all species. Nutrient loading increased N and P concentrations of plants by up to 80% and 127%, respectively, by luxury nutrient consumption, and after planting, nutrient-loaded seedlings produced 1.5-fold the biomass of conventionally fertilised seedlings, this being the result of greater root productivity. In conclusion, optimising nursery nutrient regimes for framework species may increase root-growth potential, assisting in improving plant establishment in restoration programs.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/BT10184
Abstract: Protocols for in vitro propagation of two critically endangered species, Commersonia adenothalia C.F.Wilkins ms and Commersonia sp. Mt Groper (R. Cranfield & D. Kabay 9157), from south-western Western Australia were established utilising both shoot and in vitro leaf explants. Regeneration from leaf explants was highest, with an average of four shoots per leaf explant per a 4-week incubation period on ½-strength Murashige and Skoog (MS) medium with 2.5 µM thidiazuron (TDZ) + 2.5 µM 3-indoleacetic acid (IAA) for C. adenothalia and 13 shoots per leaf explant on ½-strength MS medium + 4.5 µM 6-benzylaminopurine (BAP) and 2.5 µM 1-naphthaleneacetic acid (NAA) for C. sp. Mt Groper. Shoot proliferation using single shoot explants of C. adenothalia resulted in a maximum average of 3.5 shoots per shoot explant per a 5-week incubation period on ½-strength MS medium + 5 µM kinetin and 0.5 µM BAP, whereas maximum mean shoot multiplication with C. sp. Mt Groper (×30 shoots per shoot explant per a 5-week incubation period) was recorded with ½-strength MS medium + 2.5 µM kinetin and 1 µM BAP. In general, C. sp. Mt Groper was much more reactive to cytokinins than was C. adenothalia, with prolific regeneration of shoots from leaf explants or shoot explants. Both species produced roots readily on ½-strength MS medium without added hormones or with 5 µM indole-3-butyric acid (IBA) (100% rooting in 3–4 weeks) and rooted plantlets survived the transition to soil (~70% survival).
Publisher: Wiley
Date: 05-12-2017
Publisher: Elsevier BV
Date: 10-2009
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.TPLANTS.2016.11.002
Abstract: Seed coating is the practice of covering seeds with external materials to improve handling, protection, and, to a lesser extent, germination enhancement and plant establishment. With an annual value exceeding US$1 billion dollars, this technology is mostly the preserve of the private research sector, with few links to the scientific community. Here, we analyse the science and industry of seed coating and its contribution to seed establishment and plant performance. We posit that a closer collaboration between academia and industry is critical to realising the potential of seed coating both as a tool for enhancing plant establishment in the face of the challenges posed to agricultural systems and to propel the multibillion-dollar global push for ecological restoration of degraded ecosystems.
Publisher: Wiley
Date: 15-12-2016
DOI: 10.1111/REC.12475
Publisher: Frontiers Media SA
Date: 26-11-2019
Publisher: Wiley
Date: 04-01-2022
DOI: 10.1002/LDR.4165
Abstract: Mining activities alter soil physicochemical and biological properties that are critical for plant establishment. Revitalisation of soil biological properties via microbial inoculations can potentially be adopted to improve vegetation restoration. Here, we evaluate the feasibility of using beneficial microorganisms in the form of commercially available inoculants to enhance plant performance in a non‐toxic and infertile mine‐waste substrate, using pigeon pea [ Cajanus cajan (L) Millsp.] as a test plant. Six treatments were established to investigate the effects of inoculants ( Bradyrhizobium spp., microbial mix and uninoculated controls) and water availability (low and moderate) in a factorial design over 6 months. Plant performance was determined by physiological parameters (leaf gas exchange, leaf carbon, nitrogen and stable isotopes) and growth (height and biomass). Plant xylem sap phytohormones were measured to determine the plants' physiological status and effects of inoculation treatments. Results revealed that water had a greater effect on plant growth than inoculation treatments. Inoculation treatments, however, improved some physiological parameters. This study suggests that physical conditions such as soil moisture and nutrient availability may occlude more subtle (direct or interactive) effects of beneficial soil microbes on plant growth and plant condition. Prior knowledge on the biological and physicochemical properties of the soil to be amended, and on plant species‐specific responses, would be needed to customise microbial inoculants for maximum benefits to ecological restoration, to support future adoption of this practice.
Publisher: Springer Science and Business Media LLC
Date: 13-06-2017
Publisher: International Seed Testing Association
Date: 08-2015
Publisher: Elsevier BV
Date: 12-2017
Publisher: Oxford University Press (OUP)
Date: 12-12-2009
Abstract: Discovery of the primary seed germination stimulant in smoke, 3-methyl-2H-furo[2,3-c]pyran-2-one (KAR1), has resulted in identification of a family of structurally related plant growth regulators, karrikins. KAR1 acts as a key germination trigger for many species from fire-prone, Mediterranean climates, but a molecular mechanism for this response remains unknown. We demonstrate that Arabidopsis (Arabidopsis thaliana), an ephemeral of the temperate northern hemisphere that has never, to our knowledge, been reported to be responsive to fire or smoke, rapidly and sensitively perceives karrikins. Thus, these signaling molecules may have greater significance among angiosperms than previously realized. Karrikins can trigger germination of primary dormant Arabidopsis seeds far more effectively than known phytohormones or the structurally related strigolactone GR-24. Natural variation and depth of seed dormancy affect the degree of KAR1 stimulation. Analysis of phytohormone mutant germination reveals suppression of KAR1 responses by abscisic acid and a requirement for gibberellin (GA) synthesis. The reduced germination of sleepy1 mutants is partially recovered by KAR1, which suggests that germination enhancement by karrikin is only partly DELLA dependent. While KAR1 has little effect on sensitivity to exogenous GA, it enhances expression of the GA biosynthetic genes GA3ox1 and GA3ox2 during seed imbibition. Neither abscisic acid nor GA levels in seed are appreciably affected by KAR1 treatment prior to radicle emergence, despite marked differences in germination outcome. KAR1 stimulation of Arabidopsis germination is light-dependent and reversible by far-red exposure, although limited induction of GA3ox1 still occurs in the dark. The observed requirements for light and GA biosynthesis provide the first insights into the karrikin mode of action.
Publisher: Wiley
Date: 28-05-2018
DOI: 10.1002/LDR.2980
Publisher: Oxford University Press (OUP)
Date: 05-08-2011
DOI: 10.1093/AOB/MCR198
Publisher: Wiley
Date: 11-05-2021
DOI: 10.1002/ECE3.7638
Abstract: Recruitment for many arid‐zone plant species is expected to be impacted by the projected increase in soil temperature and prolonged droughts associated with global climate change. As seed dormancy is considered a strategy to avoid unfavorable conditions, understanding the mechanisms underpinning vulnerability to these factors is critical for plant recruitment in intact communities, as well as for restoration efforts in arid ecosystems. This study determined the effects of temperature and water stress on recruitment processes in six grass species in the genus Triodia R.Br. from the Australian arid zone. Experiments in controlled environments were conducted on dormant and less‐dormant seeds at constant temperatures of 25°C, 30°C, 35°C, and 40°C, under well‐watered (Ψ soil = −0.15 MPa) and water‐limited (Ψ soil = −0.35 MPa) conditions. Success at three key recruitment stages—seed germination, emergence, and survival—and final seed viability of ungerminated seeds was assessed. For all species, less‐dormant seeds germinated to higher proportions under all conditions however, subsequent seedling emergence and survival were higher in the more dormant seed treatment. An increase in temperature (35–40°C) under water‐limited conditions caused 95%–100% recruitment failure, regardless of the dormancy state. Ungerminated seeds maintained viability in dry soil however, when exposed to warm (30–40°C) and well‐watered conditions, loss of viability was greater from the less‐dormant seeds across all species. This work demonstrates that the transition from seed to established seedling is highly vulnerable to microclimatic constraints and represents a critical filter for plant recruitment in the arid zone. As we demonstrate temperature and water stress‐driven mortality between seeds and established seedlings, understanding how these factors influence recruitment in other arid‐zone species should be a high priority consideration for management actions to mitigate the impacts of global change on ecosystem resilience. The knowledge gained from these outcomes must be actively incorporated into restoration initiatives.
Publisher: Oxford University Press (OUP)
Date: 25-03-2010
DOI: 10.1093/AOB/MCQ061
Publisher: Wiley
Date: 15-05-2018
DOI: 10.1002/LDR.2945
Publisher: Wiley
Date: 07-2022
DOI: 10.1002/BES2.1993
Publisher: Elsevier BV
Date: 2021
Publisher: Wiley
Date: 11-07-2022
DOI: 10.1002/EAP.2613
Abstract: Connecting scientific research and government policy is essential for achieving objectives in sustaining bio ersity in an economic context. Our approach to connecting theoretical ecology, applied ecology, and policy was devised using principles of restoration ecology and the requisite methodology to restore bio erse ecosystems. Using a threatened ecological community (TEC) with >120 plant species, we posit our approach as a guide for interpreting and achieving regulatory compliance (i.e., government conditions) enacted to manage or offset environmental impacts of development. We inform the scientific approach necessary to delivering outcomes appropriate to policy intent and bio erse restoration through theoretical and applied research into the ecological restoration of the highly endemic flora of banded ironstone formations of the Mid West of Western Australia. Our approach (1) defines scale-appropriate restoration targets that meet regulatory compliance (e.g., Government of Western Australia Ministerial Conditions) (2) determines the optimal method to return in idual plant species to the restoration landscape (3) develops a conceptual model for our system, based on existing restoration frameworks, to optimize and facilitate the pathway to the restoration of a vegetation community (e.g., TEC) using erse research approaches and (4) develops an assessment protocol to compare restoration achievements against the expected regulatory outcomes using our experimental restoration trials as a test ex le. Our approach systematically addressed the complex challenges in setting and achieving restoration targets for an entire vegetation community, a first for a semiarid environment. We interpret our approach as an industry application relevant to policy- or regulator-mediated mine restoration programs that seek to return bio erse species assemblages at landscape scales.
Publisher: Springer Science and Business Media LLC
Date: 2003
Publisher: Elsevier BV
Date: 08-2017
Publisher: Wiley
Date: 16-12-2019
DOI: 10.1111/REC.12903
Publisher: Springer Science and Business Media LLC
Date: 06-05-2020
Publisher: Elsevier BV
Date: 05-2017
Publisher: Wiley
Date: 11-03-2014
DOI: 10.1111/PPL.12170
Abstract: Southwest Australian Banksia woodlands are highly erse plant communities that are threatened by drought- or temperature-induced mortality due to the region's changing climate. We examined water relations in dominant Banksia menziesii R. Br. trees using magnetic leaf patch cl pressure (ZIM-) probes that allow continuous, real-time monitoring of leaf water status. Multiple ZIM-probes across the crown were complemented by traditional ecophysiological measurements. During summer, early stomatal downregulation of transpiration prevented midday balancing pressures from exceeding 2.5 MPa. Diurnal patterns of ZIM-probe and pressure chamber readings agreed reasonably well, however, ZIM-probes recorded short-term dynamics, which are impossible to capture using a pressure chamber. Simultaneous recordings of three ZIM-probes evenly spaced along leaf laminas revealed intrafoliar turgor gradients, which, however, did not develop in a strictly basi- or acropetal fashion and varied with cardinal direction. Drought stress manifested as increasing daily signal litude (low leaf water status) and occasionally as rising baseline at night (delayed rehydration). These symptoms occurred more often locally than across the entire crown. Microclimate effects on leaf water status were strongest in crown regions experiencing peak morning radiation (East and North). Extreme spring temperatures preceded the sudden death of B. menziesii trees, suggesting a temperature- or humidity-related tipping point causing rapid hydraulic failure as evidenced by collapsing ZIM-probe readings from an affected tree. In a warmer and drier future, increased frequency of B. menziesii mortality will result in significantly altered community structure and ecosystem function.
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/BT20089
Abstract: The rapid expansion of urban areas worldwide is leading to native habitat loss and ecosystem fragmentation and degradation. Although the study of urbanisation’s impact on bio ersity is gaining increasing interest globally, there is still a disconnect between research recommendations and urbanisation strategies. Expansion of the Perth metropolitan area on the Swan Coastal Plain in south-western Australia, one of the world’s thirty-six bio ersity hotspots, continues to affect the Banksia Woodlands (BWs) ecosystem, a federally listed Threatened Ecological Community (TEC). Here, we utilise the framework of a 1989 review of the state of knowledge of BWs ecology and conservation to examine scientific advances made in understanding the composition, processes and functions of BWs and BWs’ species over the last 30 years. We highlight key advances in our understanding of the ecological function and role of mechanisms in BWs that are critical to the management of this ecosystem. The most encouraging change since 1989 is the integration of research between historically disparate ecological disciplines. We outline remaining ecological knowledge gaps and identify key research priorities to improve conservation efforts for this TEC. We promote a holistic consideration of BWs with our review providing a comprehensive document that researchers, planners and managers may reference. To effectively conserve ecosystems threatened by urban expansion, a range of stakeholders must be involved in the development and implementation of best practices to conserve and maintain both bio ersity and human wellbeing.
Publisher: Springer Science and Business Media LLC
Date: 10-11-2021
No related grants have been discovered for Jason Stevens.