INTACT · INTeracting effects of Abiotics and Carnivores shape herbivore Top-down effects

Herbivore top-down effects and abiotic bottom-up effects are important in structuring forest systems. Recent studies showed that carnivores may shape indirectly herbivore effects. It is largely unknown how these factors interact in complete ecosystems. The project aims to understand how large canivores and abiotics shape herbivore top-down effects. The study area is one of the most complete forest systems in Europe, the Białowieża Primeval Forest in Poland, harbouring two large carnivores (wolf, lynx) and five ungulates (bison, moose, red deer, roe deer, wild boar). To test the interactions between herbivory and abiotics we will use an experiment that was started during the previous Marie Curie Fellowship of the applicant. In this full-factorial experiment the effects of both factors on ungulates and growth of trees have been measured. Also the work started by the applicant on 'browsing lawns' will be expanded. This new concept was recently described for African systems where intensive foraging by herbivores leads to a positive feed-back on food availability and quality. By means of video cameras and small exclosures in browsing lawns we will study if similar principles operate in temperate forest systems. The interactions between carnivores and herbivores will be studied by relating data on predator presence (scats, tracks, dens) to existing data of radio-collared ungulates from the host institute. Small-scale experiments should reveal whether olfactory cues or habitat visibility are important factors in predator avoidance. The applicant will work at the institute of his previous Marie Curie Fellowship. Hence the project allows for a continuation of the established contacts within and outside the Polish institute as well as international cooperation (Netherlands, Norway). The proposed work will form the habilitation thesis of the applicant which greatly facilitates his long-term reintegration in the Polish scientific community after the duration of the project.