Padrões espaciais de Qualea grandiflora Mart. em fragmentos de cerrado no estado de São Paulo

Abstract

(Spatial patterns of Qualea grandifl ora in cerrado fragments in São Paulo state). Th e study of spatial patterns is a helpful approach to formulating hypotheses about plant population dynamics. Our aim was to search for variation in spatial patterns of Q. grandifl ora height classes at diff erent scales within and among fragments of diff erent cerrado physiognomies. Spatial patterns of the number of plants in subplots (5 x 5 m) were described and compared among six 0.5-ha plots placed in four fragments. We performed Moran’s I correlogram analysis to describe spatial patterns and tested spatial correlations of height classes by partial Mantel tests. We found 18 to 319 plants 0.5ha-1. Larger plants (height >1.5 m) had a clumped pattern in all plots, varying in numbers and magnitudes of scales independently of the physiognomy. Correlogram analysis for smaller plants was possible in only three plots, where patterns were random. In two of these cases there was signifi cant positive correlation of size classes but in the third it was not signifi cant. Abundance and spatial patterns were as diff erent within the same fragment as in diff erent ones. Th ese results show that Q. grandifl ora spatial patterns cannot be predicted based on overall characteristics of cerrado physiognomy. Th e random-to-clumped transition with size and the spatial association of classes suggest that density dependent mortality does not seem to be an important driver of Q. grandifl ora dynamics, and that spatial structure of suitable sites for recruitment to maturity may be more important.