ORCID Profile
0000-0002-6188-7122
Current Organisations
Universidade de Santiago de Compostela
,
CSIRO Black Mountain Laboratories
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Publications
A review of Australian classical biological control of weeds programs and research activities over the past 12 years
Publisher: Elsevier BV
Date: 03-2010
Glycosyl squaramides, a new class of supramolecular gelators
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0SM01075H
Abstract: First ex le of glycosyl squaramides that induce the efficient gelation of high polarity solvents and hydroethanolic mixtures.
Weedy biofuels: what can be done?
Publisher: Elsevier BV
Date: 03-2011
Host range ofPachycerus cordiger (=P. Scabrosus) (Col.: Curculionidae)
Publisher: Springer Science and Business Media LLC
Date: 12-1993
DOI: 10.1007/BF02373088
What controls the population dynamics of the invasive thistleCarduus nutansin its native range?
Publisher: Wiley
Date: 23-08-2006
Comparative biology of two rosette crown-feeding flies of the genus Botanophila (Dipt., Anthomyiidae) with potential for biological control of their thistle hosts
Publisher: Wiley
Date: 03-2001
Editorial for special section of papers from the International Congress on Biological Invasions
Publisher: Springer Science and Business Media LLC
Date: 14-06-2012
Open-Field Host-Specificity Testing for Potential Biological Control Agents of Onopordum Thistles
Publisher: Elsevier BV
Date: 06-1995
Seedbanks and seedling emergence of saffron thistle (Carthamus lanatus) in eastern Australian pastures
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/AR02030
Abstract: Weed management has often proved difficult because of persistent seedbanks that allow recruitment to occur for many years after the weed has otherwise been controlled. The number of seeds in seedbanks of Carthamus lanatus, a widespread and troublesome weed, has not been investigated. Little is known about longevity of its seedbanks in pastures of eastern Australia.The numbers of seeds in the soil and the rate of seed loss were investigated at 3 sites in eastern Australia. Seedbanks were found to be patchy, and they had mean densities between 815 and 2290 seeds/m2 after the main germination flush. These seedbanks decreased over time and between 11 and 15% of seeds remained in the soil after 2 years without further input. More seeds were lost in the first year than in the second year, and pasture cover did not affect the rate of seed loss.Seeds buried in mesh bags and exhumed regularly showed that dormancy was lost, induced, then lost again within the 2-year experiment. Maximum seed germinability coincided with peak germination times. The likelihood of a seed producing a seedling was reduced when seeds were sown at high density. C. lanatus seeds appear to be well adapted for persistence in eastern Australian pastures by maintaining a bank of seeds that generally germinate when conditions favour seedling survival.
Working at the interface of art and science: How best to select an agent for classical biological control?
Publisher: Elsevier BV
Date: 09-2005
Age structure and growth of the woody legume weed Cytisus scoparius in native and exotic habitats: implications for control
Publisher: Wiley
Date: 06-2003
A global view of the future for biological control of gorse, Ulex europaeus L.
Publisher: CAB International
Date: 2008
Managing saffron thistle in pastures with strategic grazing
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/RJ02018
Abstract: Saffron thistle (Carthamus lanatus L.) is a widespread and troublesome weed in grazing land throughout much of eastern Australia. Conventional control measures are not feasible in much of this area, so the prospect for controlling saffron thistle through strategic grazing with sheep was investigated. By sowing seeds, and counting seedlings that emerged, we found that as little as 2 cm of pasture cover reduced the number of seedlings that emerged by 96% compared with bare ground. Grazing experiments showed that the survival of saffron thistle rosettes was reduced by 12% in plots that were strategically rested for one month in autumn, followed by grazing at high stocking rates. Grazing in late spring, when plants produced flowering stems, killed 20% of thistles before they set seed. A comparison of thistle density and pasture composition on farms that practice strategic grazing with neighbouring farms that used continuous grazing supported these results. Pastures had few thistles when perennial grasses accounted for over 35% of groundcover. We conclude that grazing management can help control saffron thistle.
Sourcing effective biological control agents of conical snails, Cochlicella acuta, in Europe and north Africa for release in southern Australia
Publisher: Elsevier BV
Date: 07-2019
Factors affecting invasion and persistence of broom Cytisus scoparius in Australia
Publisher: Wiley
Date: 10-2002
Can an integrated management approach provide a basis for long-term prevention of weed dominance in Australian pasture systems?
Publisher: Wiley
Date: 19-04-2005
Classical biological control for the protection of natural ecosystems
Publisher: Elsevier BV
Date: 08-2010
Top 20 environmental weeds for classical biological control in Europe: a review of opportunities, regulations and other barriers to adoption
Publisher: Wiley
Date: 04-2006
Population Structure of a Herbivorous Insect and Its Host Plant on a Microgeographic Scale
Publisher: Oxford University Press (OUP)
Date: 10-1993
DOI: 10.2307/2410172
Evolution of Size‐Dependent Flowering in Onopordum illyricum : A Quantitative Assessment of the Role of Stochastic Selection Pressures
Publisher: University of Chicago Press
Date: 12-1999
DOI: 10.1086/303268
Abstract: We explore the evolution of delayed, size-dependent reproduction in the monocarpic perennial Onopordum illyricum, using a range of mathematical models, parameterized with long-term field data. Analysis of the long-term data indicated that mortality, flowering, and growth were age and size dependent. Using mixed models, we estimated the variance about each of these relationships and also in idual-specific effects. For the field populations, recruitment was the main density-dependent process, although there were weak effects of local density on growth and mortality. Using parameterized growth models, which assume plants grow along a deterministic trajectory, we predict plants should flower at sizes approximately 50% smaller than observed in the field. We then develop a simple criterion, termed the "1-yr look-ahead criterion," based on equating seed production now with that of next year, allowing for mortality and growth, to determine at what size a plant should flower. This model allows the incorporation of variance about the growth function and in idual-specific effects. The model predicts flowering at sizes approximately double that observed, indicating that variance about the growth curve selects for larger sizes at flowering. The 1-yr look-ahead approach is approximate because it ignores growth opportunities more than 1 yr ahead. To assess the accuracy of this approach, we develop a more complicated dynamic state variable model. Both models give similar results indicating the utility of the 1-yr look-ahead criterion. To allow for temporal variation in the model parameters, we used an in idual-based model with a genetic algorithm. This gave very accurate prediction of the observed flowering strategies. Sensitivity analysis of the model suggested that temporal variation in the parameters of the growth equation made waiting to flower more risky, so selected for smaller sizes at flowering. The models clearly indicate the need to incorporate stochastic variation in life-history analyses.
Seasonal life-history models for the integrated management of the invasive weed nodding thistle Carduus nutans in Australia
Publisher: Wiley
Date: 06-2006
Predicting biological weed control
Publisher: Elsevier BV
Date: 09-1992
Dispersal and demography contributions to population spread ofCarduus nutansin its native and invaded ranges
Publisher: Wiley
Date: 07-2008
Biosecurity as an integral part of the new bioeconomy: a path to a more sustainable future
Publisher: Elsevier BV
Date: 03-2011
Biosecurity and sustainability within the growing global bioeconomy
Publisher: Elsevier BV
Date: 03-2011
Biodiversity needs a scientific approach
Publisher: Springer Science and Business Media LLC
Date: 10-2012
DOI: 10.1038/490037A
Native-range research assists risk analysis for non-targets in weed biological control: the cautionary tale of the broom seed beetle
Publisher: Wiley
Date: 11-2006
Implications of individual variation in insect behavior for host specificity testing in weed biocontrol
Publisher: Springer Science and Business Media LLC
Date: 19-06-2013
Experts know more than just facts: eliciting functional understanding to help prioritise weed biological control targets
Publisher: Springer Science and Business Media LLC
Date: 06-2016
Development of cercospora blight epidemics and effect on the summer annual Heliotropium europaeum in the field
Publisher: Wiley
Date: 08-1995
A Model for Plant Invasions: the Role of Distributed Generation Times
Publisher: Springer Science and Business Media LLC
Date: 02-05-2009
DOI: 10.1007/S11538-009-9422-X
Abstract: An analytical model consisting of adult plants and two types of seeds (unripe and mature) is considered and successfully tested using experimental data available for some invasive weeds (Echium plantagineum, Cytisus scoparius, Carduus nutans andCarduus acanthoides) from their native and exotic ranges. The model accounts for probability distribution functions (pdfs) for times of germination, growth, death and dispersal on two dimensions, so the general life-cycle of in iduals is considered with high level of description. Our work provides for the first time, for a model containing all that life-cycle information, explicit relationship conditions for the invasive success and expressions for the speed of invasive fronts, which can be useful tools for invasions assessment. The expressions derived allow us to prove that the different phenotypes showed by the weeds in their native (exotic) ranges can explain their corresponding non-invasive (invasive) behavior.
Mutualism vs. antagonism in introduced and native ranges: Can seed dispersal and predation determine Acacia invasion success?
Publisher: Elsevier BV
Date: 06-2013
Prioritizing species, pathways, and sites to achieve conservation targets for biological invasion
Publisher: Springer Science and Business Media LLC
Date: 21-11-2015
Gene technologies in weed management: a technical feasibility analysis
Publisher: Elsevier BV
Date: 04-2020
Quantifying the social and economic benefits of the biological control of invasive alien plants in natural ecosystems
Publisher: Elsevier BV
Date: 04-2020
Variation in pathogenicity of isolates of Cercospora spp. attacking Heliotropium spp.
Publisher: Wiley
Date: 06-1996
Axenic culture and influence of wetness period and inoculum concentration on infection and development of cercospora blight ofHeliotropium europaeum
Publisher: Springer Science and Business Media LLC
Date: 09-1995
DOI: 10.1007/BF01874472
The double life cycle of Lepidapion argentatum, a promising candidate for the biological control of French Broom.
Publisher: Informa UK Limited
Date: 24-03-2019
The invertebrate fauna on broom, Cytisus scoparius,in two native and two exotic habitats
Publisher: Elsevier BV
Date: 05-2000
Worth the risk? Introduction of legumes can cause more harm than good: an Australian perspective
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SB01025
Abstract: Weeds are serious threats to Australia's primary production and bio ersity conservation. For ex le, a recent Australia Bureau of Statistics survey found that 47% of farmers across Australia have a significant weed problem. A literature review revealed that legumes represent a significant proportion of the national weed problem and most serious Australian legume weeds are exotic thicket-forming species that were deliberately introduced for their perceived beneficial properties, such as for shade and fodder, or even quite trivial reasons, such as garden ornamentals. The low economic value of the rangelands most of these species infest, compared with control costs, hinders chemical and mechanical control of these weeds, such that biological control, which takes time, is expensive to implement and has no guarantee of success, may represent the only economically viable alternative to abandoning vast tracts of land. We argue that, because the behaviour of an introduced species in a novel environment is so hard to forecast, better predictive techniques should be developed prior to further introductions of plant species into novel environments. We also discuss the potential of legumes currently being promoted in Australia to become weeds and suggest the recent trend of exporting Australian Acacia spp. to semiarid regions of Africa risks history repeating itself and the development of new weed problems that mirror those posed by Australian Acacia spp. in southern Africa.
Evolution of flowering decisions in a stochastic, density-dependent environment
Publisher: Proceedings of the National Academy of Sciences
Date: 29-07-2008
Abstract: Demography is central to both ecology and evolution, and characterizing the feedback between ecology and evolution is critical for understanding organisms' life histories and how these might evolve through time. Here, we show how, by combining a range of theoretical approaches with the statistical analysis of in idually structured databases, accurate prediction of life history decisions is possible in natural density-regulated populations undergoing large fluctuations in demographic rates from year to year. Our predictions are remarkably accurate and statistically well defined. In addition, we show that the predicted trait values are evolutionarily and convergence stable and that protected polymorphisms are possible.
Biological control of the cane toad in Australia: A review
Publisher: Wiley
Date: 04-11-2010
Factors affecting the establishment of Cytisus scoparius in southern France: implications for managing both native and exotic populations
Publisher: Wiley
Date: 08-1998
Pollinators and predators at home and away: do they determine invasion success for Australian Acacia in New Zealand?
Publisher: Wiley
Date: 22-12-2014
DOI: 10.1111/JBI.12455
The impact of a root-crown weevil and pasture competition on the winter annual Echium plantagineum
Publisher: Wiley
Date: 04-2001
Evolution in agriculture: the application of evolutionary approaches to the management of biotic interactions in agro‐ecosystems
Publisher: Wiley
Date: 17-02-2011
DOI: 10.1111/J.1752-4571.2010.00179.X
Abstract: Anthropogenic impacts increasingly drive ecological and evolutionary processes at many spatio‐temporal scales, demanding greater capacity to predict and manage their consequences. This is particularly true for agro‐ecosystems, which not only comprise a significant proportion of land use, but which also involve conflicting imperatives to expand or intensify production while simultaneously reducing environmental impacts. These imperatives reinforce the likelihood of further major changes in agriculture over the next 30–40 years. Key transformations include genetic technologies as well as changes in land use. The use of evolutionary principles is not new in agriculture (e.g. crop breeding, domestication of animals, management of selection for pest resistance), but given land‐use trends and other transformative processes in production landscapes, ecological and evolutionary research in agro‐ecosystems must consider such issues in a broader systems context. Here, we focus on biotic interactions involving pests and pathogens as exemplars of situations where integration of agronomic, ecological and evolutionary perspectives has practical value. Although their presence in agro‐ecosystems may be new, many traits involved in these associations evolved in natural settings. We advocate the use of predictive frameworks based on evolutionary models as pre‐emptive management tools and identify some specific research opportunities to facilitate this. We conclude with a brief discussion of multidisciplinary approaches in applied evolutionary problems.
The effect of a rosette-crown fly, Botanophila turcica, on growth,biomass allocation and reproduction of the thistle Carthamus lanatus
Publisher: Elsevier BV
Date: 11-2000
Selection of pathogen agents in weed biological control: critical issues and peculiarities in relation to arthropod agents
Publisher: Wiley
Date: 26-09-2006
The comparative demography of the pasture weed Echium plantagineum between its native and invaded ranges
Publisher: Wiley
Date: 04-2001
The role of plant phenology in the host specificity of Gephyraulus raphanistri (Diptera: Cecidomyiidae) associated with Raphanus spp. (Brassicaceae)
Publisher: Biology Centre, AS CR
Date: 15-02-2008
The taxonomic status of Larinus cynarae F. and Larinus latus Herbst (coleoptera: Curculionidae), and its implications for the biological control of Onopordum (asteraceae: Cardueae) in Australia
Publisher: Informa UK Limited
Date: 1992
Safe and effective biocontrol of common carp
Publisher: Springer Science and Business Media LLC
Date: 03-04-2017
Effectiveness of classical weed biological control agents released in Australia
Publisher: Elsevier BV
Date: 03-2022
Stable coexistence of an invasive plant and biocontrol agent: a parameterized coupled plant-herbivore model
Publisher: Wiley
Date: 02-2005
Genetic variability in the parasitic fly, Sarcophaga villeneuveana, in south-western Europe and Morocco
Publisher: Springer Science and Business Media LLC
Date: 09-12-2019
CONTEXT-DEPENDENT BIOLOGICAL CONTROL OF AN INVASIVE THISTLE
Publisher: Wiley
Date: 12-2005
DOI: 10.1890/05-0195
Structure of the phytophagous insect fauna of Onopordum thistles in the northern Mediterranean basin
Publisher: Oxford University Press (OUP)
Date: 11-1994
Optimal management strategies to control local population growth or population spread may not be the same
Publisher: Wiley
Date: 06-2010
DOI: 10.1890/09-0316.1
Abstract: The objective of most pest management programs is to "control" the pest species. However, optimal control of local abundance and population growth may require different management strategies than optimal control of spatial spread. We use coupled demographic-dispersal models to address the relative importance of different management approaches to these two main control objectives for the invasive thistle Carduus nutans. The models are parameterized with data from thistle populations in the native (France) and invaded ranges (Australia and New Zealand). We assess a wide range of commonly used management strategies for their absolute and relative impacts on population growth and spread in both invaded-range scenarios. The projected population growth rate in New Zealand is more than twice that in Australia, while the spread rate is more than four times the Australian value. In general, spread and growth are both most strongly affected by the same life cycle transitions however, in a few cases certain vital rates disproportionately affect either spread or growth. The transition that represents the contribution of large rosettes in one year to the number of large rosettes in the following year (the large rosette-large rosette transition) in Australia is dominated by reproduction (rather than survival) and hence is relatively more important to spread than to population growth. In New Zealand, the small rosette-small rosette transition is also predominantly dispersal-related. However, establishment of small plants from the seed bank contributes more to population growth than spread, as no dispersal is involved. The fine-resolution vital-rate-based modeling approach allows us to identify potentially novel optimal management strategies: approaches that reduce microsite availability show promise for reducing both population growth and spread, while strategies that affect dispersal parameters will affect spread. Additionally, the relative ranking of some biocontrol agents shifts depending on whether control of population growth or population spread is the desired outcome and therefore could alter which of the agents are preferred for release in a new area. The possibility of differences in ranked agent effectiveness has been predicted theoretically, but never before demonstrated using field data.
Plant biosecurity policy-making modelled on the human immune system: What would it look like?
Publisher: Elsevier BV
Date: 08-2014
Effect of patch size and plant density of Patersons curse ( Echium plantagineum ) on the oviposition of a specialist weevil, Mogulones larvatus
Publisher: Springer Science and Business Media LLC
Date: 15-09-2000
Abstract: This study examines the oviposition response of a specialist weevil (Mogulones larvatus) to patches of its host, the noxious weed Paterson"s curse/salvation Jane (Echium plantagineum). We simultaneously examined the effect of patch size and plant density (and their interaction), on the recorded oviposition patterns. Our results show that oviposition first occurred on the largest patches with the highest number of plants. However, there was no significant effect of patch size or number of plants per patch at the end of the experiment. At this time the level of attack per plant was negatively correlated with plant density. This negative effect of density on the level of oviposition was not mediated by a reduction in plant size at higher densities. The pattern observed may indicate a risk-spreading strategy by females.
Weed biological control in Zimbabwe: Challenges and future prospects
Publisher: Elsevier BV
Date: 03-2023
A modelling approach to estimate the effect of exotic pollinators on exotic weed population dynamics: bumblebees and broom in Australia
Publisher: Wiley
Date: 09-2006
Fortieth anniversary review of the CSIRO European Laboratory: does native range research provide good return on investment?
Publisher: CAB International
Date: 2008
Prioritising environmental invasive weeds of European concern for classical biological control: A reanalysis
Publisher: Wiley
Date: 12-04-2023
DOI: 10.1111/WRE.12582
Abstract: Invasive alien plant species (IAPs) are causing significant negative impacts on agricultural production, threatened native species and ecosystems, the services they provide and public health thereby affecting European bio ersity and its economy. IAPs invade all types of natural and managed habitat and their impacts, through increased numbers and area invaded, are growing exponentially. Current control options in Europe are largely limited to manual and chemical control, which is high cost, short‐term in effectiveness and with regards to chemical control declining in public acceptability. Globally, classical biological control (CBC) is widely and successfully used to manage many IAPs. CBC aims to redress the ecological imbalance caused by the IAPs, generally being released without their natural enemies. The steps are to select, risk assess potential specific natural enemy biocontrol agents of the IAP (from the IAP's native range) and follow regulatory approval prior to releasing them to ecologically suppress their abundance. CBC is not widely used in Europe. Only five active programmes exist. In this paper, we apply an existing framework to develop a ranked list of environmental IAPs named in the EU Regulation on Invasive Species for biocontrol. We used a scoring system based on existing knowledge on the IAPs impacts, the amount of effort needed to deliver a CBC programme targeting them and the feasibility and likelihood of success of such programmes. We identify 16 IAPs in Europe for which CBC has relatively high potential and discuss existing knowledge that can underpin any future investments in such activities against each of these IAPs. The top three species being Pontederia crassipes , Pistia startiotes and Acacia saligna . This research should support decision‐making on the instigation of future CBC programmes against environmental IAPs in Europe. We set this analysis in the context of other operational and regulatory constraints on developing CBC programmes against environmental IAPs in Europe.
The Importance of Weeds in Plant Biosecurity
Publisher: Springer Netherlands
Date: 16-10-2014
Detailed assessment of the reported economic costs of invasive species in Australia
Publisher: Pensoft Publishers
Date: 29-07-2021
DOI: 10.3897/NEOBIOTA.67.58834
Abstract: The legacy of deliberate and accidental introductions of invasive alien species to Australia has had a hefty economic toll, yet quantifying the magnitude of the costs associated with direct loss and damage, as well as for management interventions, remains elusive. This is because the reliability of cost estimates and under-s ling have not been determined. We provide the first detailed analysis of the reported costs associated with invasive species to the Australian economy since the 1960s, based on the recently published InvaCost database and supplementary information, for a total of 2078 unique cost entries. Since the 1960s, Australia has spent or incurred losses totalling at least US$298.58 billion (2017 value) or AU$389.59 billion (2017 average exchange rate) from invasive species. However, this is an underestimate given that costs rise as the number of estimates increases following a power law. There was an average 1.8–6.3-fold increase in the total costs per decade since the 1970s to the present, producing estimated costs of US$6.09–57.91 billion year -1 (all costs combined) or US$225.31 million–6.84 billion year -1 (observed, highly reliable costs only). Costs arising from plant species were the highest among kingdoms (US$151.68 billion), although most of the costs were not attributable to single species. Of the identified weedy species, the costliest were annual ryegrass ( Lolium rigidum ), parthenium ( Parthenium hysterophorus ) and ragwort ( Senecio jacobaea ). The four costliest classes were mammals (US$48.63 billion), insects (US$11.95 billion), eudicots (US$4.10 billion) and monocots (US$1.92 billion). The three costliest species were all animals – cats ( Felis catus ), rabbits ( Oryctolagus cuniculus ) and red imported fire ants ( Solenopsis invicta ). Each State/Territory had a different suite of major costs by species, but with most (3–62%) costs derived from one to three species per political unit. Most (61%) of the reported costs applied to multiple environments and 73% of the total pertained to direct damage or loss compared to management costs only, with both of these findings reflecting the availability of data. Rising incursions of invasive species will continue to have substantial costs for the Australian economy, but with better investment, standardised assessments and reporting and coordinated interventions (including eradications), some of these costs could be substantially reduced.
Biosecurity in the new bioeconomy
Publisher: Elsevier BV
Date: 03-2011
Incorporating uncertainty and social values in managing invasive alien species: a deliberative multi-criteria evaluation approach
Publisher: Springer Science and Business Media LLC
Date: 09-08-2011
Scientific advances in the analysis of direct risks of weed biological control agents to nontarget plants
Publisher: Elsevier BV
Date: 12-2005
First Records of Flesh Flies (Diptera: Sarcophagidae) Emerging from Terrestrial Snails in Morocco
Publisher: Academy of Science of South Africa
Date: 03-2018
DOI: 10.4001/003.026.0124
Spatial economics of biological control: investing in new releases of insects for earlier limitation of Paterson's curse in Australia
Publisher: Wiley
Date: 11-2002
The scope and value of extensive ecological studies in the broom biological control programme.
Publisher: CABI Publishing
Date: 11-12-2000
Seed predators and the evolutionarily stable flowering strategy in the invasive plant, Carduus nutans
Publisher: Springer Science and Business Media LLC
Date: 27-09-2008
Prioritized list of potential biological control agents from South Africa for fireweed (Senecio madagascariensis) in Australia
Publisher: CSIRO
Date: 2016
Below-ground Herbivory in Carduus nutans (Asteraceae) and the Potential for Biological Control
Publisher: Informa UK Limited
Date: 09-1995
Predicting the economic impacts of invasive species: the eradication of the giant sensitive plant from Western Australia.
Publisher: CABI
Date: 2015
DOI: 10.1079/9781780643946.0145
Abstract: conomic analyses can facilitate biosecurity investment decisions in relation to pest risk management. The term biosecurity here refers to activities intended to prevent or control the introduction and spread of alien species that have a net negative effect on social welfare as determined by economic, environmental and social capital. The aim of the chapter is to demonstrate a model that indicates an appropriate level of funding that decision makers should allocate to specific pest management activities based on anticipated returns. We demonstrate the model with a recently introduced weed species to Western Australia, Mimosa pigra. This weed has been targeted for eradication and the analysis described here estimates the amount biosecurity managers should spend on eradication before costs begin to outweigh the likely returns.
Prioritized list of potential biological control agents from South Africa for fireweed (Senecio madagascariensis) in Australia
Publisher: CSIRO
Date: 2016
Seed Dormancy and Delayed Flowering in Monocarpic Plants: Selective Interactions in a Stochastic Environment
Publisher: University of Chicago Press
Date: 08-2006
DOI: 10.1086/505762
Abstract: We explore the effects of temporal variation in multiple demographic rates on the joint evolution of delayed reproduction and seed dormancy using integral projection models (IPMs). To do this, we extend the standard IPM to include a discrete state variable representing the number of seeds in the seed bank, density-dependent recruitment, and temporal variation in demography. Parameter estimates for Carlina vulgaris and Carduus nutans are obtained from long-term studies. Carlina is relatively long lived and has a short-lived seed bank, whereas most Carduus plants flower in their first year and the seed bank is long lived. Using the evolutionarily stable strategy (ESS) approach, we predict the observed flowering and germination strategies. There is excellent agreement between the predictions and the field observations. The effects of temporal variation on the joint ESS are partitioned into components arising from nonlinear averaging (systematic changes in the mean resulting from the interaction between variability and nonlinearity) and nonequilibrium dynamics (fluctuations in fitness caused by temporal variation). This shows that temporal variation can have substantial effects on the observed flowering and germination strategies and that covariance between demographic processes is important. We extend the models to include spatial population structure and assess the robustness of the results from the nonspatial models.
Global threat to agriculture from invasive species
Publisher: Proceedings of the National Academy of Sciences
Date: 20-06-2016
Abstract: A key scientific and policy challenge relating to invasive species at the world level is to understand and predict which countries are most vulnerable to the threat of invasive species. We present an analysis of the threat from almost 1,300 agricultural invasive species to the world (124 countries). The analysis examines the global distribution of these species, international trade flows, and each country’s main agricultural production crops, to determine potential invasion and impact of these invasive species. We found the most vulnerable countries to be from Sub-Saharan Africa, while those countries representing the greatest threat to the rest of the world (given the invasive species they already contain, and their trade patterns) to be the United States and China.
The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management
Publisher: Elsevier BV
Date: 06-2012
Reduced availability of rhizobia limits the performance but not invasiveness of introduced A cacia
Publisher: Wiley
Date: 31-07-2013
Using karyotyping and achene morphology to accurately identify Sonchus oleraceus (Asteraceae) in the context of its biological control
Publisher: Cold Spring Harbor Laboratory
Date: 28-02-2020
DOI: 10.1101/2020.02.26.965863
Abstract: In weed biocontrol, accurate identification of the target weed is essential to select effective and host-specific biocontrol agents. This study focuses on the biocontrol of an invasive weed species in Australia, native from Europe, the common sowthistle, Sonchus oleraceus L. (Asteraceae). During field surveys, the distinction between S. oleraceus and a morphologically related species ( S. asper L.) was difficult because of specimens bearing intermediate morphological features. These observations raised questions about the reliability the morphological characters used for distinguishing between these species and the identity of the intermediate phenotypes. First, cytological analyses coupled with morphological comparisons were carried out on specimens collected in Europe and Australia. Results showed that specimens morphologically described as S. oleraceus and S. asper possessed, in accordance with literature 32 and 18 chromosomes, respectively. Specimens with intermediate morphotypes had 32 chromosomes, showing that they belong to S. oleraceus species. The variability of characters used for diagnosis is discussed and for a particular feature, achene ornamentation, an inquiry among 30 people was carried out to determine how this character might be relevant for distinguishing the two species herein considered. The successful identification rate was 92.2% (SE ± 0.77) showing the practical interest of this feature for diagnosis.
Related Organisations
Imperial College London
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
No related grants have been discovered for Andy Sheppard.