Plant communities in veredas: distribution of native tree/shrubby regeneration and of the invasive species Pinus caribaea Morelet.

This work aimed to identify: (1) heterogeneity patterns in veredas, considering tree/shrubby regeneration and chemical and physical characteristics of the soil; (2) how the vereda zones (edge, intermediate and core) can influence the tree/shrubby regeneration and (3) which microenvironmental characteristics determine the distribution of native tree/shrubby regenerants and of the invasive species Pinus caribaea Morelet. For this, we collected environmental and biophysical data and sampled the regeneration of tree/shrubby species in 30 plots in two different veredas. The moisture and chemical characteristics of the soil, and regeneration composition were similar among the vereda zones, but showed important variations among sample units. In addition to soil moisture, soil chemical elements and canopy coverage characteristics also formed environmental gradients. The native tree/shrubby species occupied different positions along the environmental gradient of the veredas. The invasive species P. caribaea was more concentrated in less declined sites, in more basic and more humid soils, together with most native species. In general, the results demonstrate the absence of clear zoning, as well as the importance of environmental heterogeneity and the control of biological invasion for the maintenance of native tree/shrub regeneration. [ABSTRACT FROM AUTHOR]