The effects of habitat fragmentation on bird communities in Hyrcanian forests (Case study: Gorgan Township)

Habitat destruction is one of the main factors threatening species so thatuntil 1980 about 30 percent of species became endangered because ofdegradation and destruction of wildlife habitat. birds were surveyed in fourdifferent patch sizes (<1 ha, 1-10 ha, 10-25 ha and >300 ha). environmentalvariables, including forest cover type, characteristics of the structure andcomplexity of vegetation and those of landscape as well as the number ofbirds were recorded within a 25-m radius of each of 74 sampling points.results showed that habitat variables including vegetation type, number ofsnags, number of logs, number of trees with dbh 0- 20, 20-50, 50-100, 100-300 cm and basal area were the most important variables affecting thepresence of birds in the study area. the results of this study highlighted theimportance of forest patches and their attributes in conservation andenhancement of bird’s habitat as well as in conservation of biodiversity offorest ecosystems.