Baumann, M. 2022. Systematic investigation of the bryophyte flora as a basis for monitoring in the strict nature reserve Naturwaldzelle Zweibach and in managed reference sites in the Ore Mountains (Saxony). – Herzogia 35: 395 – 419. The results of the first systematic bryophyte species survey in the strict forest reserve Naturwaldzelle Zweibach (Ore Mountains, Saxony federal state, Germany) are presented. Species inventories were done in the unmanaged strict forest reserve (30.5 ha) and managed reference sites in the immediate vicinity (70.8 ha). The study included a survey of ground-dwelling bryophytes (humus/mineral soil) in systematically distributed permanent sample plots as well as an overall mapping of the area, including all substrates. With a total of 180 species, a very rich bryophyte flora was encountered, including numerous endangered species. This is due to the heterogeneity of the area with occurrences of different types of forest communities (near-natural beech forest, spruce plantation), rock outcrops, large boulders, springs and forest brooks. While the bryophyte layer on the forest floor was only sparsely developed in the beech stands, it had a higher cover and number of species below spruce. In the substrates deadwood and especially tree bark, however, the ratios were reversed, where species diversity was significantly higher in beech stands. Both in the strict forest reserve and in the managed reference area, mainly typical forest bryophytes were found, the proportion of species preferring open land conditions was low. With regard to the two management categories, there was a tendency to different indicator values, particularly for lower light conditions in the strict forest reserve.