Global demographic genomics Do you find it frustrating that every ecological study seems to use a different method, meaning we can't compare across time or space?PLANTPOPNET was set up to establish a globally consistent protocol to make faster progress in understanding plant performance and adaptation with global change.
As part of the PLANTPOPNET team, I am exploring how the environment shapes spatial genomic patterns in Plantago lanceolata,
while also examining the influence of population growth and survival
rates on genomic structure.
The species has an enormous distribution, allowing us to address the following questions: How much gene flow occurs across the native range? What are the sources of non-native populations? Where are the hybrid zones where rapid adaptation might occur? This will be followed up by a finer-scale analysis to understand how environmental and demographic variation influences genomic structure. I am based inProf. Yvonne Buckley's lab (PLANTPOPNET HQ) at Trinity College Dublin, co-supervised by Dr Trevor Hodkinson.
The role of fire in historical plant evolution is well understood but there is little knowledge of how species will adapt to the unprecedented changes in fire regimes which are occurring globally.
There is ample evidence that invasive plant species can rapidly adapt to new environments but no studies have yet examined rapid evolution of fire-adaptive traits (e.g. fire-stimulated germination) in invasive species. This is surprising considering that invasive species can alter fire regimes when they change fuel properties and when fire promotes their establishment and growth. The result is a positive ecological feedback, whereby the invasion process accelerates and fire frequency and/or intensity increases, sometimes beyond the level where native vegetation can recover. But do adaptive changes contribute to these feedbacks?
We are investigating if adaptation in invasive species can reinforce changes in fire regimes by increasing the persistence of fire-tolerant or fire-promoting lineages. Keep reading...
Science-based grassland restoration
With continuing urban expansion, biodiversity conservation and human asset protection often
require different regimes for managing wildfire risk. I am collaborating on a project led by Dr Richard Milner (Australian Captial Territory Parks and Conservation) to develop new ways of restoring habitat for threatened species while reducing fire fuel load in a rapidly developing urban area around Canberra, Australia.
Read about the pilot phase of this project and see our recently published scientific paper. Surveys have been completed for a broad-scale restoration experiment across five grassland reserves and analysis is underway. This is a good example of adaptive management: each phase of the restoration project is being applied in an experimental context, allowing scientific findings to guide the next phase.
Species invasiveness and community invasibility Dr Jane Catford (University of Melbourne) is leading an experiment from Cedar Creek Ecosystem Science Reserve, USA to understand how plant species invade ecosystems. Jane works with David Tilman at Cedar Creek who, back in the 90’s, found that species-rich sites were more resistant to invasion and that dispersal and recruitment limitation were more important than local species interactions. Now, with 20 years of data on community composition and species traits from the same sites, it possible to examine long-term dynamics in species invasiveness and community invasibility. In particular, how do the ecological traits of invading species interact with the resident community to influence different stages of invasion? I am leading the analysis of this rich data set to tackle these questions with Jane and her Cedar Creek team.
Check out the original paper: Tilman (1994) Community invasibility, recruitment limitation and grassland biodiversity. Ecology, 78(1), 81–92. And stay tuned for a update...
Mechanistic fire ecology in animals
Well studied changes in plant demography after fire have led to conceptual, statistical and simulation-based models to predict the effects of different fire regimes on vegetation. Progress in this direction for animals has been slower than for plants, partly because of the difficulty in obtaining animal life history data. At the community level, a functional trait-based approach for predicting fire responses (like those used for plants) holds promise for use in animal studies. However, this approach requires detailed information on life history traits, including survival, reproduction and dispersal which is not available for most animal species in fire-prone ecosystems. Understanding demographic changes of animal populations after fire is critical if we are to develop a predictive framework for ecological fire management.
This was the subject of my PhD (supervised by Prof. Don Driscoll) and has led to many publications. Here are some of my favourites:
Life history influences how fire affects genetic diversity in lizards (a landscape genetics approach) Read more
Functional-trait analysis of reptile community responses to fire. This shows we're not quite there yet, and that a massive sampling effort is required to detect responses to fire in reptiles Read more
Post-fire succession affects survival, reproduction and population density but not detectability in geckos Read more
Invertebrate responses to fire, while interesting in themselves, can give us insights into why reptile and other insectivores respond in the way they do. This paper also presents some interesting findings about sampling issues for detecting ecological responses in invertebrates Read more