Scales of variability of surface vegetation: Calculation and implications for climate models

The presence in the vegetation landscape of many varied scales of organization implies a complex set of land/atmosphere interactions. Larger scales of variability at the surface induce boundary layer heterogeneity and may induce secondary boundary layer circulation patterns. The quantification of the scales of heterogeneity in the surface vegetation, therefore, is essential to the understanding and modeling of the land/ atmosphere interactions. The present study analyzes the scales of heterogeneity in the surface vegetation by using a satellite-derived land class category map and a discrete analysis tool. Results show substantial variability in scales near 1000 km for most land class categories other than Deciduous Broadleaf Forest. Implications for GCM modeling approaches to the land/atmosphere interactions were drawn based on the results of the study. Results are consistent with the use of a 'mosaic' rather than a 'mixture' approach and with extending the 'mosaic' approach up through the boundary layer.