University of Tehran Journal of Natural Environment 2008-7764 66 4 2014 02 20 Bird species richness and diversity along an altitudinal gradient in North of Alborz Mountain (Case study: Kheyrud forest) Bird species richness and diversity along an altitudinal gradient in North of Alborz Mountain (Case study: Kheyrud forest) 365 376 36609 10.22059/jne.2014.36609 FA Mitra Shariatie Msc Environmental, Department of Fishery and Environment, Faculty of Natural Resources, University of Tehran Mohammad Kaboli Assistant Professor, Department of Fishery and Environment, Faculty of Natural Resources, University of Tehran 0000-0002-9203-2346 Journal Article 2011 12 31 A monotonic decline in species richness and diversity with increasing elevation has often been considered as a general pattern, but recent evidence suggests that the dominant pattern is hump-shaped or unimodal with maximum richness occurring at some mid-elevation point. This study was conducted in Kheyrud forest, Mazandaran province. The study area was divided into six elevation levels according to plant communities. Sampling was carried out in mid-spring at 163 random sampling points, which were located with a minimum distance of 250 m apart, as well as a minimum distance of 25 m from the edge of forest. We applied "unlimited radius point count" using "sit and wait" method to count observed and/or heard bird species from dawn until 10:00 am, lasting on average 10 minutes, and avoiding windy and rainy weathers. Our results revealed the existence of significant differences in richness and diversity between elevation classes. Also, we found a hump-shaped pattern of bird species richness and diversity against elevation, reaching the maximum at mid-elevation. These results highlight the importance of forest communities at mid-elevation in North of Alborz Mountain Range and suggest that silvicultural practices should be managed to conserve biodiversity at this elevation zone. A monotonic decline in species richness and diversity with increasing elevation has often been considered as a general pattern, but recent evidence suggests that the dominant pattern is hump-shaped or unimodal with maximum richness occurring at some mid-elevation point. This study was conducted in Kheyrud forest, Mazandaran province. The study area was divided into six elevation levels according to plant communities. Sampling was carried out in mid-spring at 163 random sampling points, which were located with a minimum distance of 250 m apart, as well as a minimum distance of 25 m from the edge of forest. We applied "unlimited radius point count" using "sit and wait" method to count observed and/or heard bird species from dawn until 10:00 am, lasting on average 10 minutes, and avoiding windy and rainy weathers. Our results revealed the existence of significant differences in richness and diversity between elevation classes. Also, we found a hump-shaped pattern of bird species richness and diversity against elevation, reaching the maximum at mid-elevation. These results highlight the importance of forest communities at mid-elevation in North of Alborz Mountain Range and suggest that silvicultural practices should be managed to conserve biodiversity at this elevation zone. https://jne.ut.ac.ir/article_36609_65a94d815f628b0ce363958b8142ee58.pdf