The passports of key forest ecosystems seem to be a proper ground for assessment as they clearly summarize the basic information and characteristics: key systems (group of forest types) delineation, altitudal and spatial distribution, natural, present and optimum stand composition, occurrences of endangered and protected species, threat of natural and anthropogenic abiotic and biotic factors, stability/vulnerability analysis, carrying capacity, management principles. The contents and telling capacity of the passports as their application capacities in the planning of the sustainable development can be deduced from the examples of forest ecosystems which illustrate two different leading specifications: important spatial distribution and representativeness.