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Résumé :
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Spring fires produce fundamental changes of the forest bird communities in the Baikal area, due to destruction of nests and habitat modifications. Out of 24 species inhabiting old pine forests, only three (Tree Pipit, Coal Tit, Scarlet Rosefinch) were still found immediately after the fire; 1 one species (Song Thrush) newly occurred. Bird abundance declined to approx. 20%. Only the Tree Pipit maintained its previous density and continued to predominate. In late summer, nine species were seen, and Great Spotted Woodpecker, Coal Tit, and Willow Tit reached the density they had prior to the fire. Total bird abundance was minimal during that phase (63 ind./kral). Three years after the fire, 12 species were found in early summer, the growth of shrubbery favouring warblers, Siberian Rubythroat, Red-flanked Bluetail, Brown Shrike (all new), and Scarlet Rosefinch. Having dominated the previous communities, the Tree Pipit exhibited a significant decline. The increasing food supply during summer (berries etc.) supported new species (Hazel Grouse, thrushes), which then occurred at high densities. However, the number of species and the total bird abundance were still below the values of the initial communities in old forests.
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