Generic Composition, Structure and Diversity of Secondary Forests at Amisconde, the Pacific Slope of the Cordillera de Talamanca, Costa Rica

Abstract

Most Costa Rican forests have been intensively studied in recent years. One exception is the transition zone from lowland wet forest to the high elevation Quercus forest belt at the pacific slopes of the Cordillera de Talamanca. An inventory of secondary forest composition, structure and diversity was done on a specific slope (1150-2300-m elevation) in the conservation and development project Amisconde. Thirteen plots of 500 m2 were evenly spread along an elevation gradient. Specimens were collected of all woody individuals (> 3 cm DBH), dried, placed in a herbarium of morphospecies and afterwards identified. In total 90 genera within 49 families were found. The vegetation was separated in three forest types using TWINSPAN classification. Forest types were elevation based. Elevation and forest age showed (overall) no correlation with diversity using ANOVA, with the single exception of a positive correlation of the number of genera and elevation. This was opposite to the negative correlations mostly found on elevation gradients. The main factors for this positive correlation were the level of recent disturbance and the distance to primary forest, in combination with forest age.