Spatial distribution of single specie dominant forests of Erythrina fusca Lour. at the Taiamã Ecological Station, Pantanal, Mato Grosso, Brazil

Abstract

The Pantanal biome has a great variety of habitats where plant species are distributed according to their particularities. This study aimed at evaluating the spatial distribution of arboreal/shrub vegetation in areas of single specie dominance Erythrina fusca forests. An aggregation test (K(t)) for E. fusca and spatial dependence tests (K(12)) between E. fusca and Calophyllum brasiliense, as well as Alchornea discolor and Banara arguta were performed. The correlation of the distance from the beginning of the plots (riverbank) to the abundance of individuals was tested, and finally, the Kernel density was estimated. We found that E. fusca is randomly distributed throughout the area, that the distribution of C. brasiliense and A. discolor is dependent on E. fusca, and that of B. arguta is not. The correlation analysis pointed to a decrease in the abundance of the community from the riverbank to the interior of the island, with a smaller reduction in the population of E. fusca. The density was higher in the regions close to the river. In addition, sites with a high concentration of individuals close to the elevations created by the roots of E. fusca were verified. The distribution of individuals was related to the flood pulse and the adaptive processes of plant establishment, where the flooding selects the species most tolerant to this type of environment, and the formation of higher microrelief in the landscape can increase the dispersion of the species. This points out that any disturbance that may occur in the flood pulse will change the environmental balance.