Objective 1. Comparative population ecology
1.1 The geography of plant population dynamics: quantifying spatial variation in population dynamics in relation to habitat suitability. Using existing global population dynamics and species occurrence databases, I will determine whether and how habitat suitability informs population dynamics.
1.2 Discovering the mechanisms linking traits, environment and biotic interactions to spatial population dynamics. I will develop and lead a new distributed network of collaborative field studies on a globally widespread plant species, Plantago lanceolata, to determine the biotic and abiotic drivers of population dynamics worldwide. Global climate change will alter plant distributions but we currently lack a mechanistic understanding of population responses to accurately forecast where, and how fast, they will shift. Global climate change will result in species extinctions, disruption of ecosystem function, and movements of species at unprecedented rates in human history. Plant population response to climate change will depend on how growth or decline of populations, together with dispersal, determines where plants can persist and move to. In order to prioritise conservation actions for threatened species, preserve vital ecosystem services provided by plants, manage undesirable species and adapt our forestry and agricultural practices we need forecasts of future plant species distributions.
Objective 2. Predicting population responses to fertilisation
2.1 Can the effects of nutrient addition on species abundance be predicted from species demographic attributes? I will determine whether species abundance responses to a multi-site nutrient and grazing experiment can be predicted using species level demographic data.
2.2 Using predictive models developed in 2.1 how well can we predict increasing and decreasing species abundances in response to nutrient addition using new test data?
Fertilization of plant species has profound impacts on species richness, composition and productivity in grasslands worldwide; however, the effects of nutrient addition varies widely among species, some species increase in abundance as a result of additional nutrients while others do not. Management of grasslands for biodiversity conservation or food security would be much improved if we could predict a priori which species are more likely to respond positively or negatively to nutrient addition. Ultimately how much and how quickly plant cover responds to nutrient addition is determined by the population level vital rates of survival, growth and reproduction. I propose to use data on 86 species from approx. 40 sites worldwide which have overlapping data in both the Nutrient Network (NutNet) and COMPADRE databases to determine if species’ responses to Nitrogen (N), Phosphorus (P) and Potassium and micronutrients (K+) can be predicted by species level demographic attributes.
Objective 3. Cost effective interventions
3.1 Development of an economic sensitivity analysis incorporating demography together with efficacy and cost of management for multiple invasive plant species.
3.2 Management strategies ranked by the economic sensitivity analysis will be compared with commonly used individual proxy rankings: cost, efficacy, demographic elasticities and managers’ expert opinions.
The impacts of invasive species are costly and management is undertaken to mitigate or prevent environmental or economic costs. However, resources available for management are limited, necessitating a greater emphasis on cost effectiveness, “bang for your buck”, and likelihood of success of management. While comparative and synthetic work on the ecology and impacts of invasive species has progressed substantially, costs and management efficacy have not been incorporated into these frameworks. We therefore lack a general understanding of the relative importance of ecology, costs and efficacy of management for reducing the impacts of invasive species. Here we propose to extend economic sensitivity analysis to incorporate management efficacy (achievable reductions in vital rates and stage transitions) and different management objectives for multiple invasive plant species to assess the relative contributions of demography, efficacy and cost for cost effective management decisions