AVIS-IBIS

Birds of Indian Subcontinent

Effects of Changing Forest Structure on Long-Term Trends in Bird Populations in SW Finland

Publication Type:Journal Article
Year of Publication:1980
Authors:Haila, Y, Järvinen, O, Väisänen, RA
Journal:Ornis Scandinavica
Volume:11
Issue:1
Date Published:1980
ISBN Number:00305693
Keywords:Anthus, Anthus trivialis, Carpodacus, Carpodacus erythrinus, Erythrina erythrina, Finland, Fringillidae, Motacillidae, Pipastes trivialis, Prunella, Prunella modularis, Prunellidae, Turdidae, Turdus, Turdus iliacus
Abstract:Nine forest habitats were studied on Åland, SW Finland, in 1926-27 and 1975. Part of the differences between the censuses may be accounted for by differences in census methods, but many changes in bird populations could be predicted on the basis of changing forest structure: the increased coverage of the bush layer after the abandonment of forest grazing, as well as the increase of spruce, scattered birch and the herb layer in certain habitats, seemed to be of importance. Increased forest fragmentation may also have played a significant role. Other causes include the mild winters preceding 1975 and changes due to new species immigrated to our insular study area (e.g. Carpodacus erythrinus). In general, non-passerines decreased, but passerines greatly increased their populations. Many species increased strikingly, e.g. Turdus iliacus, Prunella modularis and Anthus trivialis. Species diversity increased in all habitats except one, probably owing to increased foliage height diversity (increased bush and herb layers) and to increased horizontal heterogeneity of the habitats (more small habitat patches were studied in 1975 than in 1926-27).
URL:http://www.jstor.org/stable/3676261
Short Title:Ornis Scandinavica
Taxonomic name: 
Anthus (Birds), Anthus trivialis (Birds), Carpodacus (Birds), Carpodacus erythrinus (Birds), Fringillidae (Birds), Motacillidae (Birds), Prunella (Birds), Prunellidae (Birds), Turdidae (Birds), Turdus (Birds), Turdus iliacus (Birds), Turdus iliacus (Birds)
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith