The objective of this technical report was to provide guidelines for the national inventories of field research facilities related to long-term forest ecosystem and landscape research, which will be included in a European database. The guidelines were developed following the scientific framework presented in the ENFORS Technical Report No. 1 "Scientific issues related to sustainable forest management in an ecosystem and landscape perspective". The guidelines are made up of general criteria that should apply to all field research facilities to be used in a first step of the inventories. Important general criteria are: (i) a long-term research perspectives and objective, (ii) spatio-temporal scale relations, (iii) availability of documentation, and (iv) presence of linkages to other research or monitoring activites. The specific criteria that apply to different types of field research facilities will assist at the second step of the inventories, which is an iterative process for fine-tuning the database content in relation to the scientific framework and the creation of a hierarchical classification among the field research facilities.
