Ecological impact of forest disturbances – natural experiment in Białowieża Primeval Forest

Białowieża Forest is a large forest complex of high naturalness, hosting substantial proportion of European woodland biodiversity. Recently this forest has been seriously affected by the bark-beetle outbreak, which resulted in a death of nearly half of Norway spruces in the forest. Furthermore, sanitation cutting and harvesting of spruces killed by the bark-beetle were initiated at unprecedented scale at nearly 700 ha of stands killed by the beetle. As an effect, the ecosystem was hit twice: first by bark-beetle outbreak and again by the following clear-cutting. These changes in Białowieża Forest structure provide a unique opportunity to investigate ecological consequences of natural disturbance in natural conditions, and different post-disturbance management strategies, for forest biodiversity. A primary goal of the proposed project is to evaluate the ecological consequences of the forest disturbance by the bark-beetle, and post-disturbance management, for bird, bat and butterfly communities. These three groups are phylogenetically and ecologically different, have different dispersal abilities and differ in term of space use and ecological niches, thus can react differently to the disturbance and management. In 2021-2025 I plan to perform sampling of these three animal communities using novel methods of autonomous recording units (except butterflies) at sites undisturbed by the bark-beetle, at sites disturbed by the beetle, and at sites disturbed and salvaged (i.e., clear-cut; 100-250 in total, depending on the group), but also in non-forest habitats, serving here as a control (ca. 50 sites). Main aims of the project involve: estimation of magnitude of change in animal communities caused by the bark-beetle outbreak, verifying whether disturbed sites host less diverse animal communities, indicating winners and losers of the disturbance effect among three studied communities, estimating the role of landscape context in explaining local variation of communities occupying disturbed forest patches, estimating successional trajectories of the communities developing at post-disturbance sites and describing impact of post-disturbance salvaging for birds, bats and butterflies. Main motivation for the proposed research is the increasing frequency of forest disturbances (e.g., fires, windthrows, outbreaks of insects) worldwide whereas their ecological effects are still relatively poorly understood. It may be expected that increasing disturbance frequency will lead to substantial ecological transformations of forest ecosystems and forest-associated biodiversity, thus it is a need for the empirical studies analysing ecological footprint of these extreme events.