Direct and indirect effects of climate change on future forest biodiversity
Halting global biodiversity loss is a central challenge for humanity in the 21st century. One factor contributing to the ongoing loss of biodiversity is anthropogenic climate change. Climate change impacts biodiversity through direct effects, with climatic parameters influencing the life history of organisms. But also indirect effects exist, with climate change altering important habitat features, which in turn influence biodiversity. To date, the relative contributions of direct and indirect effects of climate change on biodiversity remain widely unclear. Furthermore, the potential of ecosystem management to moderate indirect climate change effects (e.g., by creating microclimatic refugia) remains poorly quantified.
Focusing on forest ecosystems, our objective here is to disentangle the different pathways of climate influence on biodiversity, harnessing the extensive biodiversity data gathered in the Biodiversity Exploratories in a novel simulation framework.
Our specific objectives are (i) to assess how strongly the microclimatic buffering under forest canopies influences diversity, (ii) to quantify how direct and indirect effects of climate change influence biodiversity throughout the 21st century, and (iii) to evaluate the potential of adaptive forest management measures to buffering indirect climate change effects on biodiversity.
We hypothesize that…
- … climate parameters are overall more important for predicting biodiversity than forest parameters (H1.1). We furthermore expect that explicitly considering microclimate will substantially improve models, particularly for immobile and ectothermic species (H1.2).
- … biodiversity will decrease overall under climate change (H2.1). We further expect that indirect effects of climate change are stronger than direct effects (H2.2).
- … alternative forest management can buffer some but not all negative effects of climate change on biodiversity (H3.1). We further expect that effects of alternative forest management will only become effective towards the end of the century (H3.2).
We focus on the diversity of plants, bryophytes, insects, bats and birds, using the wealth of data collected in the Exploratories to fit a suite of species distribution models. We subsequently link these models with a next-generation forest simulation framework, to dynamically assess the effects of changing climate and forest conditions on biodiversity. We investigate six future climate scenarios until 2100, and use a framework of counterfactual simulations to disentangle direct and indirect effects of climate change. We subsequently implement adaptive forest management measures in our simulation environment to quantify their ability to moderate indirect climate effects on biodiversity.
Scientific assistants
