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 richness 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 quadratic regression curve (y=7•41+0•1*x−0•0003*x2,p =0•008, r2=0•788). At a small spatial scale, however, neither linear nor quadratic regression 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 arid and semi-arid grasslands of north China. Landscape complexity should be considered in future studies of productivity–richness relationships.