Field Guide to Tree-related Microhabitats, Swiss Federal Institute for Forest, Snow and Landscape Research, 2020.
The team is always looking for field research methods that can be used to monitor forest biodiversity. So, fortunately, they came across the publication Field Guide to Tree-related Microhabitats by the Swiss Federal Institute for Forest, Snow and Landscape Research. This method identifies so-called "habitat trees" and is thus a perfect complement to the already tested "Index for Biodiversity Potentials IBP".
A habitat tree is defined as a tree with at least one tree-related microhabitat. A tree-related microhabitat is a morphological feature on a tree that is used by sometimes highly specialized species during at least part of their life cycle. These features may provide shelter, breeding sites, or important overwintering or feeding sites for thousands of species. Various biotic or abiotic events can create tree-related microhabitats: For example, a falling rock could injure bark, lightning could strike a tree and crack the wood, or a woodpecker could dig a breeding cavity in the trunk. For some microhabitats, such as vertebrate nests or witches' brooms, the tree is merely a physical support. To enhance biodiversity in a stand and thus improve its resilience, it is useful to know what tree-related microhabitats are present and to maintain and enhance them through appropriate management practices. In total, the field guide describes 47 different tree-related microhabitats.
More detailed descriptions of the 47 types of microhabitats. There is a marker on the photo of the tree that identifies it as a habitat tree. Source: Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 2020.
Bütler, R.; Lachat, T.; Krumm, F.; Kraus, D.; Larrieu, L. (2020): Field Guide to Tree-related Microhabitats. Descriptions and size limits for their inventory. Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Online: https://www.wsl.ch/de/publikationen/field-guide-to-tree-related-microhabitats-descriptions-and-size-limits-for-their-inventory.html
Larrieu, L., Paillet, Y., Winter, S., Bütler, R., Kraus, D., Krumm, F., Vandekerkhove, K. et al. (2018): Tree related microhabitats in temperate and Mediterranean European forests: A hierarchical typology for inventory standardization. Ecological Indicators, 84, 194-207.