Taxocenosis of psocids (Psocoptera) was studied in the territory of the Drahanská vrchovina Hills in the Czech Republic. Representative research plots were selected in forest ecosystems with natural species composition and spatial structure (small-scale strictly protected areas) as well as in forest ecosystems with altered tree species composition and spatial structure. So far the animal component has been paid insufficient attention in the studies of forest ecosystems, with just a few exceptions. As pointed out by Holuša (2003a), studying animals and their communities faces numerous obstacles caused for example by the hidden way of the life of certain species, complexity of obtaining the study material, complicated, time-consuming and technically demanding determination and often incomplete knowledge of the autecology of some species. The purpose of studying animals is to find regularities in their species composition within ecosystems as well as direct and indirect relations between the animal and the plant component of the studied ecosystem. In natural ecosystems, plant and animal components are dynamically balanced (Míchal 1994).In history, the animal component of ecosystems was studied in various units of the differentiation of natural conditions, from altitudinal vegetation zones (AVZs) to forest site type classification units of forest site type complexes (FSCs) or biogeocene type groups of the geobiocenological system. In the context of altitudinal vegetation zones, the existence of relations between numerous groups of invertebrates and selected vertebrate groups was investigated. Stolina (1959) studied gradations of Zeiraphera diniana and Choristoneura muriana, or Ips typographus within AVZ. Králíček and Po-