Effect of Management Intensity on Tree Taxonomic and Functional Diversity in Cocoa Agroforestry Plantations

Cocoa plantations (Theobroma cacao) are suggested as agroforestry crops that promote biodiversity conservation. Nonetheless, the role of land-use history on the taxonomic and functional diversity of trees remains poorly explored. In this study, we assessed the effect of two management intensity schemes (high and low) on the taxonomic and functional diversity of cocoa plantations’ tree community in the Soconusco region of Chiapas, Mexico. We selected seven cocoa agroforestry crops under two management schemes: three high-intensity (i.e., cultivated in initially open fields) and four low-intensity (i.e., cultivated under tree shade) crops. Then, we established five circular plots (200 m2 ) within each crop (total per crop = 0.1 ha) and recorded the diameter at breast height (dbh), height, taxonomic identity, and functional traits (growth rate, ecological status, dispersal type, leaf phenology and use) of all the crop-associated trees (dbh ≥ 10 cm). Finally, we calculated taxonomic and functional diversity indices for each management scheme. We found a lower taxonomic/functional diversity and a higher dominance of few species in the high-intensity crops than in their low-intensity counterparts. Tree density was higher in the high-intensity crops, mostly represented by the rapid-growth and highly-valuable cedar (Cedrela odorata). Our findings indicate that taxonomic and functional diversity of tree community is driven by landholders’ choices for greater land productivity. Shade trees of rapid-growth and economic value are favored in high-intensity crops, leading to impoverished assemblages. Promoting a high-diversity tree layer is urgently needed in order to increase the conservation value and ecosystem services array of agroforestry cocoa plantations