The degree of change of collembolan community structure related to anthropic soil disturbance

Abstract

Edaphic fauna play a crucial role in soil processes such as organic matter incorporation and cycling, nutrient content, soil structure, and stability. Collembolans in particular, play a very significant role in nutrient cycling and soil structure. The structure and functioning of the soil fauna can in turn be affected by soil use, leading to changes in soil characteristics and its sustainability. Therefore, the responses of soil fauna to different soil management practices, can be used as ecological indicators. Three different soil uses were researched: agricultural fields (AG) with 50 years of continuous farming, pastures entering the agricultural cycle (CG), and naturalized grasslands (NG). For each soil use, three fields were selected. Each sampling consisted of three soil samples per replicate. Collembolans were extracted from the samples and identified to family level. Five families were found: Hypogastruridae, Onychiuridae, Isotomidae, Entomobryidae, and Katiannidae. Soils were also characterized by means of physical and chemical analyses. The index of degree of change of diversity, was calculated. The results show that the biological index of degree of change can detect soil use effects on the collembolan community. Somewhat surprisingly the index showed that the diversity of collembolans is higher in the high anthropic impact site AG, followed by CG and being lower in lower impact sites, NG. The results also show that collembolan families respond differently to soil use. The families Hypogastruridae, Onychiuridae, and Isotomidae presented differences between systems. Therefore collembolan community structure can be a useful tool to assess agricultural practices´ impacts on soil.