Edge effects on epiphytic lichen diversity in the forest-steppe of the Kazakh Altai

Abstract

Background: Forests in forest-steppe ecotones are usually highly fragmented and much of the forested area is exposed to climate and land-use-related edge effects.Aim: To test the hypothesis that the epiphytic lichen diversity at the forest edges was reduced compared with that in the forest interior, and to analyse lichen diversity in comparison with the more highly elevated and more continental Mongolian Altai.Methods: Six plots each in the interior and the edge with a total of 240 Larix sibirica trees were studied in the Katon-Karagai National Park, East Kazakhstan.Results: Species richness and evenness at the tree level were higher in the interior than at the edge. The epiphytic lichen diversity in the forest interior was similar in the Kazakh and Mongolian Altai, whereas that at the forest edge was lower in the Mongolian Altai.Conclusions: Strong degradation of the forest edges in the Kazakh Altai is the probable cause of the reduced epiphytic lichen diversity compared with the interior. The similar species richness in the forest interiors of the Kazakh and Mongolian Altai suggests that the differences at the forest edge are probably, at least partly, due to different land-use regimes and not to differences in macroclimate.