Studies examining the relationship between species richness and the productivity of ecological communities have taken one of two opposite viewpoints, viewing either productivity as a primary driver of richness or richness as a driver of productivity. Recently, verbal and graphical hypotheses have been proposed that attempt to merge these perspectives by clarifying the causal pathways that link ...

Aim Maps of species richness are the basis for applied research and conservation planning as well as for theoretical research investigating patterns of richness and the processes shaping these patterns. The method used to create a richness map could influence the results of such studies, but differences between these methods have been insufficiently evaluated. We investigate how different metho...

Institute for Applied Ecology New Zealand, School of Applied Science, Auckland University of Technology, Private Bag 92006, Auckland, New Zealand, School of Biological Sciences, University of Auckland, Private Bag, Auckland, New Zealand, Environmental Change Institute, School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK, School of Geography and th...

What is the gradient? Amongst the earliest remarked, and best documented, of broad-scale spatial patterns of life on Earth is a trend for more species to be found towards lower latitudes. The latitudinal gradient in species richness is such that most extant eukaryote, perhaps also prokaryote, species are found in the tropics. Even when counted over quite small areas in which it is present, the ...

DENSLOW M. W. (Department of Biology, Appalachian State University, Boone, NC 28608), M. W. PALMER (Department of Botany, Oklahoma State University, Stillwater, OK 74078), AND Z. E. MURRELL (Department of Biology, Appalachian State University, Boone, NC 28608). Patterns of native and exotic vascular plant richness along an elevational gradient from sea level to the summit of the Appalachian Mou...

Speciation is the process that ultimately generates species richness. However, the time required for speciation to build up diversity in a region is rarely considered as an explanation for patterns of species richness. We explored this "time-for-speciation effect" on patterns of species richness in emydid turtles. Emydids show a striking pattern of high species richness in eastern North America...

Invasive species richness often is negatively correlated with native species richness at the small spatial scale of sampling plots, but positively correlated in larger areas. The pattern at small scales has been interpreted as evidence that native plants can competitively exclude invasive species. Large-scale patterns have been understood to result from environmental heterogeneity, among other ...

Land-use change is affecting Earth's capacity to support both wild species and a growing human population. The question is how best to manage landscapes for both species conservation and economic output. If large areas are protected to conserve species richness, then the unprotected areas must be used more intensively. Likewise, low-intensity use leaves less area protected but may allow wild sp...

Hypothesis: Spatial variation in species richness is caused by increased maintenance metabolic costs that increase habitat overlap and decrease species richness. Organisms: Non-volant mammals in North America. Results: The latitudinal gradient in species richness could be completely explained by variation in maintenance metabolic costs. Additional spatial variation in species richness was posit...