Scale dependence of native and alien species richness in North American floras.

Michael W. Palmer 1

Affiliations

  1. Department of Botany, Oklahoma State University, Stillwater, Oklahoma 74078, USA

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Abstract

I analyzed data from 1870 vascular floras from regions within North America to assess whether the determinants of native and alien diversity vary as a function of spatial grain. Moving window multiple regression revealed that richness of both native and alien species exhibit the expected species-area relationship, latitudinal gradient, elevation gradient, and year of publication effect. However, the strength of these factors varied between native and alien species, and as a function of scale. Alien diversity was more predictable than native diversity, and is more strongly related to elevation and latitude. For both groups, the latitudinal gradient is most pronounced at broad grains, and the elevational gradient is most pronounced at fine grains.

Keywords

exotic species, FloraS of North America Project, floristics, native species, spatial scale, species richness

How to cite

Palmer M. W. (2006) Scale dependence of native and alien species richness in North American floras. – Preslia 78: 427436