Landscape Ecology

, Volume 8, Issue 1, pp 3–18 | Cite as

The spatial extent and relative influence of landscape-level factors on wintering bird populations

  • Scott M. Pearson


The influences of the landscape matrix (complex of habitats surrounding a study plot) and within-patch vegetation were studied in bird communities wintering in the piedmont of Georgia, USA. Variation at the landscape and within-patch levels was controlled to reduce the likelihood of confounding and spurious relationships. The landscape matrix within 500 m of each study plot was quantified from aerial photographs. Statistical models using landscape matrix and within-patch vegetation variables explained 73–84% of variation in bird abundance and diversity among sites with landscape matrix variables accounting for 30–90% of the variation. Variation in bird species richness and diversity was explained solely by landscape variables. Models for individual species such as Carolina Wrens (Thyrothorus ludovicianus) and Rufous-sided Towhees (Pipilo erythrophthalmus) had r2 > 0.80, with the landscape matrix variables accounting for the majority of this variation. However, other species like Northern Cardinals (Cardinalis cardinalis) and White-throated Sparrows (Zonotrichia albicollis) were most strongly influenced by within-plot vegetation. The landscape influence extended beyond habitats immediately adjacent to the study plots as indicated by significant variables describing variation in more distant habitat patches. These analyses illustrate a technique for comparing the strength of within-patch versus landscape influences and measuring the spatial extent of the landscape influence in fine-grained landscapes.

Report No. 3955, Environmental Sciences Division, Oak Ridge National Laboratory.


species diversity patches grain Georgia 


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Copyright information

© SPB Academic Publishing bv 1993

Authors and Affiliations

  • Scott M. Pearson
    • 1
  1. 1.Department of Zoology and Institute of EcologyUniversity of GeorgiaAthensUSA

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