Khruleva O.A.1, Osipov D.V.2 2019. Latitudinal composition and spatial distribution of spiders (Aranei) in the vicinity of detached woodland (the Ary-Mas area, Taimyr) // Arthropoda Selecta. Vol.28. No.4: 582–598 [in English].
1 Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky prospekt 33, Moscow 119071, Russia. E-mail: oa-khruleva@mail.ru
2 Entomology Department, Moscow Zoo, Bolshaya Gruzinskaya 1, Moscow 123242, Russia. E-mail: spiders2000@yandex.ru
doi: 10.15298/arthsel. 28.4.13
ABSTRACT. One of the northernmost places of larch forest growth in the southern tundra subzone is in the Ary-Mas area (72.5°N). In this area, 54 species of spiders from nine families were collected; Agyneta amersaxatilis Saaristo et Koponen, 1998, Pardosa algens (Kulczyński, 1908), Semljicola beringianus (Eskov, 1989) and S. lapponicus (Holm, 1939) were first recorded on Taimyr. For the first three species, Ary-Mas is the extreme known western point of its distribution, for S. lapponicus, it is the extreme eastern one. The peculiarities of the fauna composition have been revealed for this area, as well as the pattern spatial and stratified distribution of species and chorological groups. In the aboveground layer (sweeping on herbage and shrubs) 17 species and 23% of all specimens were collected, and in the ground-litter (epigeal) layer (collection by pitfall traps and by sifting moss and litter) –– 45 species. Spider assemblages of the aboveground and ground-litter layer differed in taxonomic and latitudinal composition, as well as in the distribution pattern. Relatively rich spider assemblages in the herbage-undershrub layer (11 species, up to 50 specimens/100 sweeps) are represented only in the woodland. It was dominated by polyzonal hortobiontic Larinioides cornutus (Clerck, 1758) and Dictyna major Menge, 1869; outside the forest, their abundance was low. Spiders with arctic and hypoarctic distribution prevailed throughout the epigeal layer. Arctic spiders predominated in habitats where the zonal features of the climate are manifested in the most pure form (watershed slopes, high floodplain). Hypoarctic species play a significant role in the intrazonal habitats (sandy river bed, woodland). The high activity of arctic species distinguishes spider complexes of the Ary-Mas area from more western ones (regions of Europe and West Siberia). Obviously, in the studied territory, the detached forest plays an important role in the conservation of a number of rare species from other latitudinal fractions, as well as in the formation of relative rich hortobiontic spider assemblages under its canopy.
KEY WORDS: Russian Subarctic, Taimyr Peninsula, southern tundra, larch light forest, fauna, chorology, biotopic and stratified distribution, new records.