Abstract
The objectives of this project are to investigate how top-down (predation) and bottom-up (climate) processes impact and interact in terrestrial Fennoscandian ecosystems. Top predators perform a key function in wildlife communities by suppressing mesopredators (medium-sized predators) through competition and predation. This in turn prevents excessive predation by mesopredators on their prey species. However, the strength of top-down control of mesopredators depends on bioclimatic region (ecosystem productivity). Climate change will affect both ecosystem productivity and the strength of top-down interactions. Hence, the impacts of predicted global warming and ongoing top predator reestablishment on ecosystem structures may differ between bioclimatic regions. To date, few have investigated top-down and bottom-up processes on a scale which allows comparisons between bioclimatic regions. I will use historic and recent data from different bioclimatic regions in statistical modelling and spatially explicit population modelling to test (1) the impact of historic climate variation on Swedish predator communities in different bioclimatic regions (2) interacting impacts of top-down predation and bottom-up climate processes on mesopredators and scavengers in different bioclimatic regions and (3) how present interactions between predator functional groups impact herbivore prey and ecosystem structures and (4) how future changes in climate and top predators may impact ecosystem structures.
Sweden