Vertebrate species richness at the mesoscale: relative roles of energy and heterogeneity

Abstract

Macroscale (continental) patterns of vertebrate species richness have been related to a variety of climatic and historical influences. However, within North America and Britain, empirical evidence suggests that climatic energy is most significant. In this analysis, I examine mesoscale patterns of vertebrate species richness within the U.S. State of Wyoming. I test the generality of the species‐energy hypothesis in explaining richness at this scale using high‐resolution environmental datasets and a geographic information system (GIS). Results provide little evidence to support the hypotheses that mesoscale species richness of vertebrates follows a linear relationship with climatic energy or a hump‐shaped relationship with primary productivity. By contrast, vertebrate richness within Wyoming is most strongly associated with variability in vegetation and other aspects of environmental heterogeneity over a range of sampling grains. This result underscores the benefit of protecting a maximum diversity of vegetation and habitat types for biodiversity conservation.

Climate, vegetation, and predictable gradients in mammal species richness in southern Africa

“…Large mammals over 90 kg, for example, and scansorial, aquatic and fossorial mammals are not signi®cantly correlated with woody plant species (Tables 8 & 9), whereas small-bodied arboreal frugivores and insectivores are strongly correlated (Tables 8 & 9). This in turn is related to vegetation structure, being least in desert and greatest in evergreen rainforest, in agreement with results from North America (Fleming, 1973;Kerr & Packer, 1997;Fraser, 1998). terrestrial (Fig.…”

“…Generally it is assumed that climate has some controlling in¯uence, but exactly how is not clear, as mammals are more able to tolerate changes in climate than other animals or sessile plants because they are mobile and warm-blooded. Fraser, 1998;Shepherd, 1998), but it is probable that the effects of climate on mammal diversity will be indirect, through its effects on vegetation, the source of food and shelter. It is not useful simply to relate mammal species richness to that of plants and/or habitat, for this does not answer the fundamental question about the initial causes of predictable geographic patterns of plant or habitat diversity (e.g.…”

Evaluating the species energy relationship with the newest measures of ecosystem energy: NDVI versus MODIS primary production

“…Many species energy studies used NDVI generated from the Advanced High Resolution Radiometer (AHVRR) to represent primary production, photosynthesis, ecosystem energy (Paruelo et al, 1997;Fraser, 1998;Baily et al, 2004;Evans et al, 2006) and NDVI has shown to be a strong correlate with biodiversity of many taxonomic groups (Whiteside & Harmsworth, 1967;Abramsky & Rosenzweig, 1984;Owen, 1988;Hoffman et al, 1994;Kerr & Packer, 1999;Hawkins, Porter, et al, 2003;Hawkins et al, 2005) in many geographic regions, and at many spatial scales. In our review, comparable studies of AVHRR NDVI and breeding bird species richness found statistically significant relationships with a wide range in variation explained (14-51%) (Currie, 1991;Hurlbert & Haskell, 2003;Evans & Gaston, 2005a).…”

Spatial Grain and the Causes of Regional Diversity Gradients in Ants

“…A deeper exploration of the processes underlying those scaling laws is now under way (Ricklefs and Schluter 1993;Brown 1995;Rosenzweig 1995;Hubbell 2001;Lomolino and Weiser 2001). A vital step in this process is the careful quantification of diversity gradients at different grains and extents (Fraser 1998;Waide et al 1999;Losos and Schluter 2000;Crawley and Harral 2001;Lyons and Willig 2002;van Rensburg et al 2002). Through this combination of theory and fieldwork, ecologists will forge the next generation of biodiversity scaling laws.…”