| By combining zoning and agro-ecological management of coffee production, it is possible to reduce the impacts of agricultural practices on the environment. The objectives of this work were to identify agro-ecological zones of coffee in Puerto Rico and characterize the shade trees in the area. The zones were defined by means of three parameters: water balance, biomass production and soils quality. ArcGIS 9.0 was used for data interpolation and cartographic synthesis. Data for forest inventory were taken between June 2005 and March 2006 by means of two-steps sampling: First, random selection of farms in the 22 municipalities with major areas of shaded coffee and, second, random selection of 1000 m2 plots within each farm. An inventory of trees was done and diameter at breast height (cm), total height (m) and crown diameter (m). The data collected were used to performer structural analysis, species composition of the shaded coffee and to calculate the following biodiversity indices: Shannon-Weber, Bulla, Jaccard, Bray-Curtis, richness and equity (E). The information was analyzed within five altitudinal ranks from 0 to 1000 meters above sea level.;In the coffee area of Puerto Rico, the humidity deficit, biomass production and soils quality have the ideal values for coffee. These results indicate that the coffee zone is precisely located for good crop yields. In the agro-ecological zoning it is possible to detect marginal places near to the optimal zone for other agricultural activities. Inside the actual coffee area, a total of 63 tree species were found. Inga vera, Andira inermis and Citrus sp were the most important species accounting 52.49% of Index Value Importance and 64.25% of the basal area. Significant differences were not found in the biodiversity indexes but the values of similarity were higher in the altitudinal rank between 200 to 800 m.a.s.l. The biodiversity found in Puerto Rico through this study classifies Puerto Rico shaded coffee agro-system as a commercial polyculture system because the richness and equity of species indexes were lower than traditional polyculture. |
