Biodiversity check in the lighthouse forest reserve Sihlwald

Setting aside natural forest reserves is an important measure for the conservation and promotion of biodiversity in forests, particularly for species that depend on late forest development stages and dead wood. As part of the project "Biodiversity and habitat structures in the Wildnispark Zurich Sihlwald", we studied four taxonomic species groups (bryophytes, lichens, saproxylic beetles and wood-inhabiting fungi) on 69 sample plots from the cantonal forest inventory between 2016 and 2020. To understand how species relate to different forest parameters, we compared models based on inventory data with others using only remote sensing data. While inventory data (e.g. deadwood volume) influenced species richness of fungi, it was mainly remote sensing data (e.g. vegetation height) that influenced saproxylic beetles. Remarkably, after only 20 years without logging, the Sihlwald harbours several species highlights, such as Antrodiella citrinella, a fungus considered to be a “primeval forest species”. Our models provide valuable insights into how future biodiversity monitoring can be supported by remote sensing. In addition, the data collected represent the baseline for a long-term monitoring of biodiversity in Switzerland's largest beech natural forest reserve and will enable to follow the future development of the forest into a refuge for species that can scarcely survive in managed forests.