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An importance of the edge effect and other environmental factors on bryophyte communities has been repeatedly evaluated in boreal forests whereas only rarely in forest remnants in traditionally inhabited landscape of central Europe. Adopting the design of a previous study dealing with vascular plants, we examined whether species richness and composition of bryophyte communities in 23 forest fragments (0.1-255 ha) in a representative upland agricultural landscape in central Bohemia coincides with the same environmental factors as vascular plants and if so, whether congruently or not. According to generalized additive models, bryophyte species richness and composition were significantly related to forest vegetation type, stand basal area and soil pH, analogous to vascular plants. Distribution of human-sensitive bryophyte species was further associated with slope aspect and an unlimited longrange edge effect, shown by increased occurrence of human-sensitive bryophytes along the entire distance gradient from the forest edge (0-477 m). Communities of bryophytes and vascular plants were highly congruent in species richness, species turnover and even in number of species with similar colonization ability. We conclude that requirements of human-sensitive bryophytes are fulfilled only in the core areas of large forest fragments. The small size of most current forest fragments and the range of the edge effect suggest that spatial patterns of bryophyte species composition within forest fragments have been substantially altered in the entire region of central Europe.

Questions What are the effects of environmental and dispersal filters on vegetation in small and species‐rich fragments of temperate forests in which species richness increases along the edge–interior gradient? Location Small fragments of thermophilic forests in central Bohemia, Czech Republic. Methods Repeated vegetation surveys and seed rain samplings were conducted in 71 plots located in 17 forest fragments (0.4 to 255 ha) in an agricultural landscape in Central Europe. A subsequent assessment of seed viability was performed via germination in a greenhouse. We evaluated species richness, composition and the similarities between forest vegetation and viable available seeds, accounting for potentially significant environmental conditions. Particularly, we examined the effects of species with different associations to the forest environment in combination with prevalent dispersal strategies. Results Species richness and composition of the herb layer vegetation (including tree and shrub seedlings) in small forest fragments reflected seed distribution and, to a lesser extent, seed viability. Plant species composition showed a nested pattern according to the distance from the forest edge; the species at the edge represented a subset of the species in the forest interior. Forest specialist species with spatially limited dispersal consistently achieved the highest species richness in forest interiors (>200 m from the forest edge), although this differed depending on aspect. Species richness of generalists and open‐land species benefitted from higher light quality and vice versa for forest specialists. Conclusions Small forest fragments maintain species‐rich herb layer communities confined in area‐limited interior habitats. They do this despite being mostly or entirely under the influence of the edge effect and impoverished of forest specialists. Moreover, the species‐rich interiors of the small forest fragments are likely prone to negative changes in species composition induced either by canopy closure or opening in the future.

A selection of sites occupied by the EU-protected marsh fritillary (Euphydryas aurinia) in western Czech Republic were subjected to a vegetation survey 15 years ago and again recently. In the 66 time-replicated 25 m2 plots from 12 sites, representing the diversity of E. aurinia-occupied oligotrophic grasslands in the Slavkovský les Protected Landscape Area (and covering a fifth of the currently-occupied Czech sites), we recorded quantitative representation of vascular plants and mosses. We analysed the data using multivariate ordinations, asking how the vegetation changed between the surveys, how was it affected by the conservation management applied and how it affected occupancy by the butterfly larval nests; the vegetation patterns were interpreted using Ellenberg’s plant indicator values. Between the two surveys, the overall representation of the larval host plant, Succisa pratensis, did not change; tree and herbs layers (both grasses and forbs) increased and the moss layer decreased. Across surveys, the main driver of vascular plants’ species composition was moisture, followed by soil reaction and nitrogen, whereas in mosses, nitrogen was the main factor. The main change between the surveys was the increase of nitrogen accompanied by decreased light, probably due to increase of competitively strong plants. Butterfly occupancy declined at sites with high soil moisture and increased at sites with higher soil reaction. Mowing of moist nitrogen-rich sites, but not drier nitrogen-poor sites, increased occupancy, illustrating the need for context-dependent interventions. All the evidence thus shows that E. aurinia prefers drier, warmer and less acidic conditions within the generally moist acidic grasslands and that ongoing eutrophication represents a potential problem in the future.