Spider Assemblages of Tree Branches in Managed and Primeval Deciduous Stands of the Białowieża Forest

The Białowieża Forest is an important biodiversity hotspot on a European scale, and therefore its preservation should have a high priority. However, forest management conducted over a large area of the forest, intensive logging, and elimination of dead trees pose serious threats to many species in the forest. The main aim of this study was to determine the species composition of spider assemblages inhabiting tree branches of the Białowieża Forest and to compare their species richness and the abundance of individuals (adults and juveniles) between managed and primeval stands. Between April and November 2000, we sampled three forest types (oak–lime–hornbeam forest, ash–alder riparian forest, and alder carr) in protected primeval stands within the Białowieża National Park and in managed stands. We collected 1761 specimens from 14 families and identified 41 species. Tree branches were inhabited mainly by juveniles. Species richness was smaller in managed stands compared to primeval stands. The highest number of species was found in primeval alder carr. Our study shows a negative effect of forest management on spider assemblages in terms of species richness. We emphasize the important role of alder carr forests as potential biodiversity hotspots.

Mite communities (Acari: Mesostigmata, Oribatida) in the red belt conk, Fomitopsis pinicola (Polyporales), in Polish forests

The fruiting bodies of bracket fungi are a specific microhabitat colonized by various invertebrates of which mites (Acari) are rarely studied, and if they are, the study is usually faunistic. The aim of the research was to determine whether the diversification of mite assemblages (Mesostigmata, Oribatida) inhabiting the fruiting bodies of Fomitopsis pinicola (Sw.) P. Karst. (Polyporales) are connected with the character of the forests and/or the degree of decay (DD) of the fruiting bodies. The research was conducted at Białowieża National Park (BNP), in forests close to natural ones and in Karkonosze National Park (KNP) which was affected by a large-scale forest dieback in the 1980s. Eighty fruiting bodies (40 at each study site) of F. pinicola belonging to four DD categories were collected. In total, 4,345 individuals of 120 mite species were recorded at BNP, and 13,912 individuals of 96 species were recorded at KNP. Analyses revealed that the sample dispersion at each study site was comparable, nevertheless the samples from each study site were clearly grouped into slightly overlapping sets which allow observation of the differences between them. In the less decayed fungi (DD 1 and 2) there were fewer mite species and individual mites than in the more decayed samples (DD 3 and 4). There were also significant differences between the fauna of the fungi in each particular DD: the fauna of DD 1 differed from all others, whereas the fauna of heavily decayed fungi (DD 3 and 4) was more comparable.

Foraging Site Selection of the Middle Spotted Woodpecker (Leiopicus medius Linnaeus) in Primeval Oak-Lime-Hornbeam Forest of the Białowieża National Park: Comparison of Breeding and Non-Breeding Seasons

The distribution of the Middle Spotted Woodpecker (Leiopicus medius) is restricted to mature deciduous forests with large trees, mainly oaks (Quercus spp.). Intensive forest management resulted in the loss of many suitable habitats, thus resulting in a decline in the population of this species. This study aimed to identify the parameters of foraging sites in the breeding season (April to June) and in the non-breeding season (other months). The research was conducted in the primeval oak-lime-hornbeam forest of the Białowieża National Park, where foraging woodpeckers were observed and detailed parameters of foraging sites were recorded. During the breeding season woodpeckers foraged primarily on European hornbeams (Carpinus betulus L.), but in non-breeding season the use of this tree species decreased by a factor of two, whereas the use of Norway spruces (Picea abies Linnaeus) increased more than twice. The most preferred tree species as a foraging site in both seasons was pedunculate oak (Quercus robur Linnaeus). In the non-breeding season, woodpeckers foraged at sites located higher, and the foraging session was longer compared with the breeding season. In both seasons, woodpeckers preferred dead and large trees and prey gleaning from the tree surface was their dominant foraging technique. Our results confirmed the key role of oaks and large trees, but also revealed the importance of European hornbeams and Norway spruces as foraging sites for the Middle Spotted Woodpecker.

Lack of specialist nidicoles as a characteristic of mite assemblages inhabiting nests of the ground-nesting wood warbler, Phylloscopus sibilatrix (Aves: Passeriformes)

Bird and mammal nests provide microhabitats that support a range of other species, including invertebrates. However, the variation between communities of nest-dwelling invertebrates in different nests is poorly understood. The major aim of this study was to analyze the assemblage structure of mites from the suborder Uropodina (Acari: Mesostigmata) and from superfamily Crotonioidea (Acari: Oribatida) inhabiting nests of the wood warbler, Phylloscopus sibilatrix (Aves: Passeriformes), located on a forest floor in Białowieża Forest, in eastern Poland. We also assessed the correlation between the nest material used by the birds with the assemblage structure of Uropodina mites, and compared the results with published studies of the nests of other birds and a mammal (common mole, Talpa europaea), and also with communities of mites inhabiting the soil. The field research was conducted in the strict nature reserve of the Białowieża National Park, a near-primeval European temperate forest. In 2019, immediately after the breeding period, 69 wood warbler nests and 439 soil samples were collected. Analyses revealed assemblages of Uropodina mites inhabiting the nests that consisted of 14 species, mostly common soil species. Only five species of oribatid mites from superfamily Crotonioidea were present in the nest material. Analyzed nests had a high percentage of tree leaves and grass blades, whereas moss was the least frequent component of the nest material. The Uropodina mites were more abundant in the nests that had greater amounts of grass blades, but similar relationships were insignificant for the nests with varying amounts of tree leaves or moss. The assemblages of Uropodina mites inhabiting wood warbler nests were very similar to those found in soil and nests of the common mole, but they lacked typical nest-dwelling species of Uropodina (i.e., specialized nidicoles).

The Known, the Unknown, and the Expected: 130 Years of Research on Non-Lichenized Fungi and Fungus-Like Organisms in the Białowieża Primeval Forest, Poland

The history of mycological research and current activities in the Polish part of the Białowieża Primeval Forest are presented. The review of literature-derived and unpublished data on species of non-lichenized fungi and protozoan and chromistan fungal analogues indicates a minimum of 3504 species observed in this area. The gaps in the exploration of fungi: unstudied taxa, plant communities, habitats, hosts, and substrates, as well as the limitations of former studies, are discussed. Our estimates show that a total of 8000 fungal species possibly occur in the Białowieża National Park alone, and more than 10,000 are expected to be found in the Polish part of the Białowieża Primeval Forest. Despite more than a centennial history of mycological research, the majority of data come from only a few older scientific projects and several more recent citizen-science-related activities, emphasizing the need for a modern, interdisciplinary study on the diversity and ecology of fungi in this area.