Interacting effects of forest edge, tree diversity and forest stratum on the diversity of plants and arthropods in Germany’s largest deciduous forest

A groundbreaking study reveals that increasing tree diversity in forests can mitigate the negative impacts of forest fragmentation on plant and arthropod species richness, particularly in herb layers. Conducted in Germany's largest deciduous forest, the Hainich National Park, the research found that high tree diversity buffers edge effects, allowing forest specialist species to thrive even near edges, unlike in low-diversity beech-dominated stands where specialist species decline sharply with distance from the edge. Additionally, habitat generalist arthropods, especially smaller species, benefit from increased tree diversity, while forest specialists remain largely unaffected. The study also highlights the importance of considering forest strata, as edge effects are weaker in the canopy compared to the understory, and tree diversity has stronger, more direct impacts on beetle richness in the canopy. These findings suggest that diversifying deciduous tree species could help preserve regional biodiversity, though some forest species may still depend on old-growth pure beech forests, which are protected within UNESCO World Heritage sites.

Normann, C. Interacting effects of forest edge, tree diversity and forest stratum on the diversity of plants and arthropods in Germany’s largest deciduous forest. https://doi.org/10.53846/goediss-5626