No abstract

The structure of forests is an important stabilizing factor regarding ongoing global climate and land use change. Biodiverse mountain forests with natural structure are one of the ecosystems most endangered by these problems. We focused on the mountain forest islands of European beech (Fagus sylvatica) and their role in the natural distribution of organisms. The study area was situated in the oldest Czech national park, Krkonoše (385 km2), which is the highest mountain ridge in the country. We studied multi-taxa (lichens, beetles and hymenopterans) responses to three hierarchical spatial levels of the environment: the topography was described by the elevation gradient; the patch structure was described by canopy openness, dead wood amounts, and Norway spruce (Picea abies) cover; and the tree level was described by species of the sampled tree and its diameter. Lichens preferred higher elevations, while insect groups responded conversely. Furthermore, insect groups were mainly influenced by the inner patch structure of beech islands. Lichens may be jeopardized due to the predicted future increase in temperatures, since they would need to shift toward higher altitudes. Insects may be mainly threatened in the future by land use changes (i.e., forest management) – as indicated by an interconnection of canopy openness and the amount of dead wood.

Plantation forests with timber production as the major function are highly fragmented and disturbed regarding the tree species composition and stand area. Their closed canopies also have different microclimatic conditions compared with better studied conservation areas. We studied three beetle families (click, longhorn, and rove beetles) with different ecological demands in lowland plantation forests dominated by Sessile oak and Norway spruce in the Czech Republic. Our main interest was how their species richness, abundance, diversity, body length, rarity, red-list status, species composition and individual species were driven by the main tree species, stand area and canopy openness. We analyzed 3466 individuals from 198 beetle species and the results revealed complex and contrasting responses of the studied beetle families - click beetles mostly preferred sun-exposure and spruce as the dominant tree species, longhorn beetles mainly preferred large stands, whereas rove beetles were mostly influenced by oak as the dominant tree species and increasing area. We also observed that some species had different preferences in plantation forests than is known from the literature. The main conclusions of our results are that the dominance of non-natural spruce plantations and a large stand area (both originating from artificially replanted large clear-cuts) did not affect the majority of the studied taxa as we expected. On the other hand, our results might have been influenced by other factor, such as the current small total area of the former vegetation, which in the past might have led to extinction debt; or a large area of other conifers in the surroundings that might have promoted conifer-associated fauna.

The springtail, Tetrodontophora bielanensis, dwells in the litter and upper soil layers. This arthropod mainly inhabits humid litter and soil and prefers a cold climate. We determined the main factors influencing this springtail in forests at the landscape level in Krkonoše and site level in Orlické hory in the Czech Republic. We used passive trunk-tree traps. These traps are highly effective for sampling flightless fauna. We used 128 traps in Krkonoše and 17 traps in Orlické hory. The springtail was significantly positively influenced by the presence of Norway spruce (Picea abies) at the landscape level. Springtails’ abundance was, furthermore, influenced by the spatial distribution of the sampling sites. The negative influence of bark coverage and the presence of fungi, and positive influence of an increasing dimension of trees were significant at the site level. We argue for a more diversified management of mountainous forests with respect to forest history. This appears to be also important for mountainous forests in protected areas.

Forests in lowlands are altered by a man for a long time. The most important disturbances that have been influencing hardwood floodplain forests are foresters and floods. We focused on the influence of the forest structure and soil chemistry on forest pedobiodiversity. The study was done in floodplain forests of Sava and Dunaj rivers in Serbia. Its biota was sampled using sieving of the forest litter and upper soil, and then reared in extractors. We found 20 invertebrate taxa with nearly 2,000 individuals. Ants, land snails and beetles were analyzed in more detail. High diversity of taxa was associated with closed canopies, which was consistent with land snails. Representation of big oak trees was important for ants and beetles. Decreasing pH and increasing litter height were important for ants. Increasing amount of exchangeable magnesium and organic material influenced land snail species richness. The response of invertebrates to the studied biotic and abiotic factors revealed that there were almost differences among taxonomic groups. Therefore, small scale disturbances with most of the forest untouched would have positive influence on the whole forest-litter community in the future. Patchy structure of lowland forests maintains coexistence of organisms with contrasting demands.