SPATIAL VARIANCE IN ECOLOGY

Spatial variance of observed measures such as density is no longer vie wed as a statistical annoyance. It is now treated as a biologically im portant quantity that changes value depending on the scale of measurem ent. Processes that generate spatial variance are often inferred by ma tching scales of maximum biological spatial variance to dominant physi cal processes It the same scale. Success in this approach has been lim ited to patchiness of plant communities along environmental gradients and to patchiness of passive aquatic organisms relative to physical fl ow structures. Some progress in formalizing spatial variance has been made using empirical models derived from quantitative descriptions of pattern, bur further progress requires theoretical models of spatial v ariance and processes that generate variance as a function of spatial scale.