Submitted to: Journal of Applied Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/8/2010
Publication Date: 11/1/2010
Citation: Moco, M., Gamma-Rodrigues, E., Machado, R., Baligar, V.C. 2010. Relationships between invertebrate communities, litter quality and soil attributes under different cacao agroforestry systems in the south of Bahia, Brazil. Journal of Applied Ecology. 46:347-354. Interpretive Summary: Healthy diversified soil faunal community is a key factor for sustainable crop production in an agroforestry system. Cacao productivity is low in many regions around the world due to poor soil quality. Our research with five cacao agroforestry systems showed that soil and litter quality controls the activities of soil faunal communities. The information from this research will be useful for cacao growers to improve soil quality through improved soil faunal activities thereby improving the sustainability and productivity on cacao farms.
Technical Abstract: In order to understand how soil and litter attributes interact with the faunal community, this study was undertaken to investigate the relationship between soil and litter attributes to soil and litter fauna, and further to determine which of these attributes would be most significant in explaining the distribution of faunal communities in cacao agroforestry systems in the south of Bahia, Brazil. Soil and litter samples were collected in five cacao agroforestry systems: cacao renewed under Erythrina sp. (CRE); cacao renewed under natural forest (Cabruca - CRF); a cacao system under Erythrina sp. (CE); a cacao system under a natural forest system (Cabruca - CNF) and a cacao germplasm collection area (CGC). Soil and litter samples were also collected from natural forest (NF) near the agroforestry systems. The path analysis was used to evaluate the interdependencies among a set of variables including direct and indirect test effects that can be mediated by an intermediary variable. An average of 1367 ('126.5) individuals m-2 and 10 ('0.3) taxa per sample were found under these areas. Soil attributes and litter quality under different cacao agroforestry systems affected the diversity of the soil and litter fauna, and these attributes are potential regulators of the faunal functional groups. The chemical components related to the acidity, nutrition, and palatability is most decisive for an abundant and diverse soil and litter fauna. Attributes which affected soil fauna in cacao agroforestry systems included mainly pH besides bulk density in soil and polyphenols and lignin content in the litter. The faunal communities were more sensitive to litter quality than soil quality. The litter management could be a good practice to maintain healthy activities of faunal community, to maintain improved ecosystem functioning in cacao agroforestry systems.