Relação espécie-área em campos de murundus com diferentes históricos de perturbação

Abstract

Anthropogenic activities promote alterations in abiotic characteristics of the environment, causing changes in one of the most consistent ecology patterns, the species-area relationship. We aimed to assess the relationship between richness/abundance of plants and mounds area in floodplain campos de murundus (seasonally flooded gramineous fields with scattered mounds) surrounded by anthropogenic matrix. Furthermore, we evaluated how human activities affect these relationships and the dispersion syndromes in the community. We sampled two different campos de murundus, both surrounded by monoculture: one impacted (CMI) and another protected (CMII). We found reduction in the number of species with increasing mound area in the CMI and opposite relationship in CMII. The abundance was positively related to mound area in both sites. Regarding the dispersion syndrome, greater diversity was found in CMI. The area was a determining factor of richness patterns and abundance of plants on mounds, even in ecosystems surrounded by anthropogenic matrix. Once these sites are under the same weather conditions and show similar structure, the negative species-area relationship found in CMI indicates that anthropogenic pressure in this field has been effective in eliminating species, in disagreement with the expected pattern of increased number of species for natural communities.