How does wildlife cope with global change?
Global change poses diverse threats to wild-living animals, for example habitat fragmentation and degradation, climate change, and pollution. Understanding how populations and communities respond to such challenges is a precondition to formulate the conservation measures for mitigating and curbing the negative trends. I study phenotypic variation in morphological and behavioural traits of wildlife, and how it allows coping with changing environments by means of phenotypic plasticity (e.g. Radchuk et al. 2019). I further ask ‘To what extent phenotypic trait changes that happen in response to environmental change affect population dynamics?’ (see sTraitChange project). For this part of my research I combine advanced statistical analyses (e.g. structural equation modelling, meta-analysis) with simulation models (such as matrix projection models and individual-based models). I apply these tools to long-term data of wild animal species that are collected by many researchers with whom I collaborate, and without whose work such comparative across-systems studies would have not been possible.
Stability across levels of organisation
I am fascinated by the concept of stability of ecological systems. The variety of uses of this concept and the confusion it generated is bewildering. A consensus is emerging that stability cannot be measured by one single metric and instead several metrics are required to quantify its different properties. This sheds some light on why different researchers interpreted the concept differently. In my research I aim to contribute to the conceptual development in the field of stability ecology and to facilitate quantification of stability by developing the needed statistical tools. For example, in recent research (Figueiredo et al, in prep) we developed an R package eStar that allows quantifying different metrics of stability, at different levels of organisation (e.g. species and community). This work was mainly done by Ludmilla Figueiredo (a former post-doc).
Movement and dispersal: their role in population and community dynamics
When faced with changing environments individuals can respond by changing their phenotypes (see research theme 1) or move to other suitable habitats. Therefore, understanding how movement and dispersal in response to changing environments affects population dynamics is needed to accurately assess the ability of populations and species to cope with global change. By moving to not yet inhabited habitats individuals will change their community composition and may strongly affect community dynamics (up to extinction of local species). Moreover, even while on move individuals share information and interact with other con- and hetero-specifics, with possible implications for population dynamics. However, there is no systematic approach to inferring such interactions among moving individuals from observational telemetry data. And this is a focus of a PhD research within this theme. For this part of my research I employ simulation models (individual-based models) and a combination of advanced statistical methods (e.g. state-space models).
Sebastian Achter - 'Systematic Literature Reviews on Agent-based Models'