Tree related microhabitats in temperate and Mediterranean European forests: A hierarchical typology for inventory standardization

Tree-related microhabitats (TreMs) – like cavities, bark pockets, crown deadwood, fungi, and epiphytes – are vital for the many forest species that depend on them for part of their life cycle. Yet, until now, there has been no common agreement on how to define or record them.

This publication establishes the first standardized definition and typology for TreMs in temperate and Mediterranean forests across Europe. It identifies seven main forms, further divided into 15 groups and 47 detailed types, based on their morphology and biodiversity value. The framework enables TreM data to be collected and compared across countries, forest types, and management systems.

Beyond harmonizing research, the typology provides a practical tool for managers and policymakers to integrate TreMs into forest inventories, identify habitat trees, and assess forest conservation value more accurately. It also underlines the need for continued research on TreM dynamics and their role in forest biodiversity.

By providing shared definitions and field methods, this work strengthens the link between forest management, monitoring, and biodiversity conservation – helping to ensure that living and dead trees alike are recognized for the habitats they host.