Spatial patterns of grassland communities under eucalyptus plantation

Abstract

The study aimed at evaluating spatial vegetation patterns, based on species and plant functional types (C3, C4), to relate these patterns to light conditions and to generate hypothesis about the temporal dynamics of the grassland vegetation in response to the development of a two year old eucalyptus plantation. The survey was carried out on 66 plots of 0.25 m2 located between the rows of eucalyptus, on four transects across the boundary of the plantation. A total of 164 species was found in the survey. Species had their cover-abundance estimated in each plot and were classified with respect to the photosynthetic pathway. In one of the transects, light conditions under the canopy were evaluated; significant association between shading and community patterns in terms of species (P = 0.001) and functional types (P = 0.007) was found. The results allow to postulate the hypothesis that the increase in shading with the development of the eucalyptus canopy produces reduction in the cover-abundance of C4 species and increase in C3 species, more tolerant to shading.