Agroforestry benefits on dung beetle diversity of the Andean-Chocó region in Ecuador

Conversion of natural landscapes by fragmentation and habitat modification is one of the main causes of biodiversity loss and damage to ecosystem functioning, and studies focused on modified landscapes make it possible to infer how specific land uses, such as conversion to agriculture, affect ecosystem structure and function. Here, we examine how dung beetle assemblages in the Andean-Chocó region in Ecuador vary with land use, including conventional agroecosystems with cacao and coffee production crops and reference forests at a similar elevation.

We used a pitfall trapping methodology, using traps baited with human feces, each site encompassed three 60 × 60 m plots, featuring agricultural crop types (Cacao and Coffee), control sites (pristine forests), and seasonal periods (wet and dry). Sampling locations included agroforestry Cacao (AECa) and Coffee (AECo), conventional Cacao (TCa) and Coffee (TCo), and reference forests associated with Cacao (CaF) and Coffee (CoF). To characterize the total biodiversity of different treatments, we used three integrated rarefaction extrapolation curves based on three Hill numbers: species richness, the exponential of Shannon entropy, and the inverse Simpson entropy. We also used Beta diversity measured as the dissimilarity between the assemblages.

We collected a total of 4,380 specimens and identified 47 species of dung beetles. The areas and season with the greatest dung beetle diversity were the agroforestry cacao and reference forests and the wet season. Beta diversity was highest in Cacao ecosystems, while the Coffee plantations had the high levels of nestedness. Reference forests for the two agroecosystems exhibited higher biomass, followed by areas with agroforestry management. From these results, we can infer that agroforestry production systems in the Andean-Chocó region can contribute to the maintenance of insect species richness and ecosystem functioning and could be viable alternative conservation systems and used as biological corridors.