Influences of horizontal and vertical aspects of land cover and their interactions with regional factors on patterns of avian species-richness

 Brian M. Napoletano, Bryan C. Pijanowski, John B. Dunning, Jr.

Influences of horizontal and vertical aspects of land cover and their interactions with regional factors on patterns of avian species-richness. 
Cogent Environmental Science: Vol 3, No 1,1296604.

Abstract

We examined how both horizontal and vertical aspects of land-cover diversity influence patterns of avian species-richness across North America. Using count data from Breeding Bird Survey routes within the conterminous USA and land-cover data from the National Land Cover Data-set, we analyzed relationships between species-richness estimates, vegetative strata, landscape diversity and elevation and geographic position using both linear-regression models and a classification and regression tree. We found that latitude, the diversity of land-cover classes present, and the proportion of the landscape containing cover-classes representing 3 vegetative strata had the strongest influence on species richness. This illustrates that, while broad-scale biodiversity trends are strongly influenced by dominant regional factors, they are also sensitive to the structure of the intermediate-level landscape. Thus, factors at multiple scales must be considered when modeling spatial patterns of biodiversity such as avian species-richness.