Spatial variability in a silvibanan agroforestry system, on the coast of Rio Grande do Sul with gvSIG

Abstract

Agroforestry systems (AS) are important alternatives to generate income from sustainable agriculture, like the AS in the North Coast of Rio Grande do Sul (RS), Brazil. However, there are still few studies that use the precision agriculture or precision forest approach, using the spatialization of attributes of the vegetation AS, this being the objective of this research. An inventory was carried out, with random sampling and the Sixth Prodan Tree Method, in a silvibanan AS located in Três Cachoeiras (RS), with 33 sample units (su) were installed to measure tree individuals with CBH >15 cm. The su were georeferenced, the phytosociological parameters were calculated, which were interpolated by weighting the inverse of the distance (IDW) in the gvSIG, which together with the AS limits gave rise to spatial variability maps. The main species observed was juçara palm (Euterpe edulis Mart. - Family Arecaceae) having 75 individuals sampled, with relative dominance, frequency and density of 17, 22.2 and 37%, respectively, and importance value of 76.2%. The variables that showed evident spatial variability were number of species, maximum diversity, the index of diversity, dominance and equability, number of palm trees and bunches of green banana. It is concluded that the attributes of the silvibanan AS have spatial variability and that the methodology used was adequate.