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A latitudinal gradient in large‐scale beta diversity for vascular plants in North America
Author(s) -
Qian Hong,
Ricklefs Robert E.
Publication year - 2007
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/j.1461-0248.2007.01066.x
Subject(s) - latitude , jaccard index , beta diversity , biological dispersal , ecology , gamma diversity , geography , species diversity , alpha diversity , biodiversity , geographical distance , diversity index , biogeography , physical geography , biology , species richness , demography , population , geodesy , artificial intelligence , pattern recognition (psychology) , sociology , computer science
Species turnover, or beta diversity, has been predicted to decrease with increasing latitude, but few studies have tested this relationship. Here, we examined the beta diversity–latitude relationship for vascular plants at a continental scale, based on complete species lists of native vascular plants for entire states or provinces in North America (north of Mexico). We calculated beta diversity as the slope of the relationship between the natural logarithm of the Jaccard index (ln J ) for families, genera or species, and both geographic distance and climate difference within five latitude zones. We found that beta diversity decreased from south to north; within latitude zones, it decreased from species to genera and families. Geographic and climatic distance explained about the same proportion of the variance in ln J in zones south of c. 50°N. North of this latitude, nearly all the explained variance in ln J was attributable to geographic distance. Therefore, decreasing beta diversity from south to north reflects decreasing climate differentiation within more northerly latitude zones, and primarily post‐glacial dispersal limitation north of 50°N.