SMALL-ScALE VAScuLAR PLAnt SPEcIES RIcHnESS In SOutHWEStERn ARKAnSAS BLAcKLAnd PRAIRIES

We describe the small-scale (0.0001, 0.001, 0.1 ha.) species richness and soils of blackland prairies in southwestern Arkansas. Areas sampled were Saratoga Blackland Prairie natural Area, Rick Evans Grandview Prairie Wildlife Management Area, and terre noire natural Area. Four 0.1 ha plots had 134 species and averaged 64.8 species, eight 0.001 ha plots averaged 22.1 species, and eight 0.0001 ha plots averaged 14.5 species. the most diverse families were Asteraceae (37 species), Poaceae (23 species), and Fabaceae (11 species). the soils are predominantly alkaline high-calcium silty clay loams. the soils are similar to those of other blackland/isolated prairies in the southeast except for their higher calcium levels. ninety-eight percent of the species were native. the occurrence of only three exotic species in the plots indicates that these sites are in very good condition.