STRUCTURE OF BREEDING BIRD COMMUNITIES IN URBAN AND SUB-URBAN GREEN AREAS OF LVIV CITY WITH DIFFERENT DEGREE OF ANTHROPOGENIC PRESSURE

Abstract

Difference in structure of breeding bird communities in the habitats with varying degrees of human activity is considered. Hemeroby classification, taking into account the cumulative effects of many factors on the habitat was applied. According to this classification, the model plots in Lviv city and suburbs areas belong to groups of oligo-, meso-, α-eu- and β-euhemerobic habitats. It is established that on the investigated territory, there is no inverse relationship between the rates of species richness and degree of anthropogenic pressure. The highest values of biodiversity are inherent to oligohe­merobic habitats with minor anthropogenic impacts and β-euhemerobic habitats with continuous and strong anthropogenic impacts. The number of breeding species in all β-euhe­merobic plots (N = 58) is even greater than on oligohemerobic plots (N = 40). The lowest indices of biodiversity and breeding density were found on α-euhemerobic areas. Differences were found when comparing forest habitats of oligo- and mesohe­merobic groups. In the mesohemerobic habitats, there are fewer species (N = 22) and lower average breeding density (32.7 pairs/10 ha), while both oligoheme­robic areas these are N = 33 and 50.2 pairs/10 ha respectively. Indices of Shannon, Margalef and Menghini also have lower values for the mesohemerobic areas, and dominance index of Berger–Parker, on the contrary, is higher. Unlike the mesohemerobic habitats in the oligoheme­robic habitats breeding species listed in the Red Book of Ukraine were observed. Thus, in more intensively loaded forests there is a depletion of biodiversity is observed. Environmental groups differ by the way of breeding due to more cavity-nes­ting species in the oligohemerobic habitats; by foraging substrate – due to a greater part of urbanized species in the mesohemerobic habitats.