An avifaunal zonation of Switzerland and its relation to environmental conditions

Abstract

1 We propose a quantitative zonation of Switzerland based on the distribution of breeding birds. We use a combined dataset from two nationwide bird censuses 20 years apart to account for distribution changes between the censuses. This approach approximates the 'potential' distribution of species more closely than a dataset from one period only. 2 A numerical approach with correspondence analysis and non-hierarchical clustering resulted in five avifaunal regions, consisting of two lowland regions north of the alpine arch, two alpine regions and one region of southern alpine valleys. 3 We identified characteristic species for each region using the indicator value analysis of Dufrêne & Legendre (1997) and determined environmental conditions separating the regions with discriminant analysis. 4 Our zonation partly corresponds with previous subdivisions of Switzerland, but has the advantage of being based on a numerical approach instead of expert knowledge. 5 We discuss avifaunal and ecological differences between the regions and relate our zonation to the classical biogeographic regions of Europe. Finally, we evaluate the importance of the zonation for bird conservation.

Integrating individual habitat choices and regional distribution of a biodiversity indicator and top predator

“…richness of vertebrate species, richness of vulnerable avian species) peaks in low‐elevation areas rich in wetlands (e.g. Pasinelli et al. , 2001; Sergio, 2002).…”

“…richness of vertebrate species, richness of vulnerable avian species) peaks in lowelevation areas rich in wetlands (e.g. Pasinelli et al, 2001;Sergio, 2002). As eagle owls are top predators within the low-elevation ecosystems of the Alps (Sergio et al, 2003a) and select areas rich in wetlands (see 'Results'), we tested (1) whether 10-km grid quadrats where eagle owls were present had higher levels of biodiversity than quadrats without eagle owls and (2) whether biodiversity was related to the percentage of the quadrat classified as suitable owl habitat by the GIS model.…”

Multivariate analysis of a fine‐scale breeding bird atlas using a geographical information system and partial canonical correspondence analysis: environmental and spatial effects

“…, 2002). In the context of multispecies analysis, atlases and GIS have already been used to provide environmental interpretation of avifaunal zonation (Pasinelli et al. , 2001), to model species richness distribution (Lobo et al.…”

“…Dennis & Hardy, 1999;Guisan et al, 1999;Luoto et al, 2002). In the context of multispecies analysis, atlases and GIS have already been used to provide environmental interpretation of avifaunal zonation (Pasinelli et al, 2001), to model species richness distribution Lobo & Martin-Piera, 2002;Maes et al, 2003) and to relate avian (Natuhara & Imai, 1996;Storch et al, 2003) or floristic (Guisan et al, 1999) assemblages to environmental conditions. In order to explain relationships between species assemblages and environmental variables, ordination methods are often used, especially direct gradient analyses in which species occurrence or abundance are directly related to environmental variables (ter Braak, 1986).…”

The Effect of Scale-Dependent Habitat Gradients on the Structure of Bird Assemblages in the Czech Republic

“…However, we suggest that this bias is relatively small as different sets of species occupy these habitats (Skórka et al 2006). Moreover, the gradient "from forest to farmland (or steppe)" is probably the strongest gradient in the bird community structure worldwide (Fuller et al 1997, Brawn et al 2001, Pasinelli et al 2001, Berg 2002, Waltert et al 2005, Reif et al 2007) and reflects deep differences in selection pressures that take place in these habitats (Wiens 1989).…”