Scale, Concept and Effects
It is a familiar experience that taxonomic diversity increases as more area is examined, as more time is spent watching an area, as more organisms are collected, and as a wider range of body sizes are accumulated. These increases in diversity do not scale directly with area, time, collection size, or body size. Over 50 years ago C.B. Williams found that on average, a 10-fold increase in area will increase the number of plant species by a factor of 2, rather than 10. Williams ascribed divergence from a 1:1 scaling to the vagaries of sampling (at the scale of plots), to habitat diversity (at the scale of biogeographic regions), and to evolutionary history (at the scale of continents). Subsequent work has confirmed this empirical scaling, developed a wealth of empirical scalings by area, developed alternatives to scaling by area, and tested theoretical explanations for these scaling relations. Biodiversity now includes genetic and habitat diversity, in addition to taxonomic diversity. This article presents the quantitative basis for scaling of biodiversity, based on rapid development of scaling theory in ecology in the last decade. Published in Levin, S.A. (Ed.), Encyclopedia of Biodiversity (Vol. 5, pp. 245-254). San Diego: Academic Press. 2001.
01 Jan 2001
NSERC Individual Grant
Strategic Research Theme
Oceans, Fisheries and Aquaculture