Spiders (Arachnida, Araneae) of the Holosiyvskiy Forest (Kyiv City): Summary Results of Araneological Research Over the Last 15 Years

Background. The study of the biological diversity of urban ecosystems, which are constantly under anthropogenic influence, is an important task in terms of understanding the dynamics of processes occurring within these groups. Species complexes of spiders are characterized by high diversity and abundance in both natural and anthropogenically modified biocenoses. The history of research on spiders in the Holosiivskyi forest began only in the 21st century and is reflected in several works. In particular, during the research on spiders in city parks in Kyiv, 44 species of spiders were identified for the Holosiivskyi park and their distribution across forest layers was noted (Singaevsky, & Balan, 2010). Data on the species composition of spiders in the botanical garden of the National University of Life and Environmental Sciences of Ukraine are emerging (Zinchenko, Singaevsky, & Balan, 2012). There is information available on the population structure of herpetobiont spiders in the Holosiivskyi Forest (spring aspect), but the duration of these studies does not allow establishing the seasonal dynamics of communities (Singaevsky, 2012). Further inventory of the spider fauna of the Holosiivskyi National Park is an important task in the context of assessing the biodiversity of forest ecosystems within the megacities of Ukraine. The purpose of this article is to analyze the species composition of the spider fauna of the Holosiivskyi Forest based on the results of many years of material collection, to provide an ecological and faunistic characteristic of new and rare species for the region, and to characterize the structure of communities. Methods. The faunal material was collected in 5 main points within the Holosiiv forest and by route method. Most of the faunal material was collected by the Barber soil trap method – a total of 4062 trap-days were used. Plastic containers with a hole diameter of 8.7 cm and a volume of 0.5 dm3 were used as traps, filled to ⅓ with a 2–4 % formalin solution with the addition of detergent. Traps were installed in rows of 5 pieces with intervals of 10 m. The contents of the traps were removed every 10–15 days. The litter, soil surface, grass layer, crowns and tree trunks were also examined. Results. The species composition of spiders in the Holosiivskyi Forest includes 101 species from 22 families. Faunal material for each species is presented. The most widely represented family is Linyphiidae – 38 species. The following families are represented in terms of representation: Theridiidae – 11 species, Lycosidae – 10, Thomisidae – 6 and Gnaphosidae – 5 species. The Araneidae and Tetragnathidae families each have 4 species. The Anyphaenidae, Atypidae, Cicurinidae, Dysderidae, Mimetidae, Phrurolithidae and Pisauridae families have one species each. Within the Linyphiidae family, the genera Walckenaeria – 5 species, Ceratinella – 4 species, Diplocephalus and Neriene – 3 species each were found to be rich in species. The Ceratinella genus is represented by almost the complete set of European species, except for C. wideri. In the experimental plot of hornbeam-oak associations on the ravine relief, data were obtained on seasonal changes in species richness, dynamic density of herpetobiont spider communities, and phenological features of some species. The dominant species of the litter layer are Ozyptila praticola (20.2 %) and Diplostyla concolor (17 %). Conclusions. For the first time in the city of Kyiv and Kyiv region, 6 species were discovered in the spider community of the Holosiivskyi forest: Ceratinella major, Diplocephalus latifrons (family Linyphiidae), Apostenus fuscus (family Liocranidae), Arctosa leopardus, Pardosa maisa (family Lycosidae) and Robertus neglectus (family Theridiidae). Detailed information on their ecological features, distribution and findings on the territory of Ukraine is provided for these species. The peak of species richness and dynamic abundance is observed in the second decade of June (16 species and 14.5 individuals/10 trap-days). The epigeobiont spider community of the hornbeam-oak forest is characterized by significant seasonal fluctuations in dynamic density: the peak was recorded in the second-third decade of June (13.4 individuals/10 trap-days). The minimum indicator is 0.13 specimens/10 trap-days from the second decade of October to the first decade of November. Depending on the season, the values of the dynamic density of spiders in the Holosiivskyi forest fluctuated more than 60 times.