Effects of landscape matrix and habitat structure on a bird community in northern Finland: a multi-scale approach

Abstrakti

The effects of scale, landscape matrix and habitat structure on birds were studied in forest-dominated landscapes in northern Finland. Abundances of birds correlated with different factors at different scales. No edge effect was observed at the large scale matrix level (4 km2), even though edge was the most important factor at the small-scale matrix level (4 ha). Matrix components explained up to 47% of the variation in abundances of birds. Fragmentation and amount of edges had a positive relationship with the managed forest species, edge species and habitat generalists. However, virgin forest species and hole-nesters had a negative relationship with edges. Landscape matrix components were more important than habitat components to the managed forest species and the Willow Warbler; whereas habitat components were more important to the migratory species and the Pied Flycatcher. Within a habitat, floristic components were more important than structural components. Habitat generalist species benefited from deciduous forests and virgin forest birds from mixed-tree species composition. Stand age had a positive relationship with species richness, total amount of birds, virgin forest species and hole-nesters. Our results indicate that bird responses to the environment are scale-dependent and individualistic. Bird species composition and abundances are also dependent on factors at larger scales than the individual's immediate habitat.