Relationship between species richness of small mammals and primary productivity of arid and semi-arid grasslands in north China

We studied the relationship between primary productivity and species richne ss of small mammals at both large and small spatial scales in the arid and semi-arid grasslands of north China. The productivity (x)-species richness (y) pattern at a large spatial scale can be described by a unimodal quadrat ic regression curve (y = 7.41 + 0.1*x - 0.0003*x(2), p = 0.008, r(2) = 0.78 8). At a small spatial scale, however, neither linear nor quadratic regress ion fit the data for 1980 and 1994 (p > 0.25). Primary productivity may not be an appropriate predictor of the species richness of small mammals at a small spatial scale. We conclude, therefore, that the primary productivity- species richness pattern of small mammals may be scale-dependent in the ari d and semi-arid grasslands of north China. Landscape complexity should be c onsidered in future studies of productivity-richness relationships. (C) 199 9 Academic Press.