Managing soil to support soil biodiversity in protected areas agroecosystems: a comparison between arable lands, olive groves, and vineyards in the Conero Park (Italy)

Sustainable soil management is essential to conserve soil biodiversity and its provision of vital ecosystem services. The EU Biodiversity Strategy for 2030 highlights the key role of organic farming and land protection in halting biodiversity loss, including edaphic biodiversity. To assess the effectiveness of the proposed measures, a 1-year study was conducted in spring 2022 to determine the soil quality of three organically managed agroecosystems and four sites for each: arable lands, olive groves, and vineyards in the Conero Park, using the arthropod-based Biological Soil Quality Index (QBS-ar) and also considering soil chemical-physical characteristics. Soil microarthropods are sensitive indicators of the impact of agricultural practices on soil quality. Given the diversity of the agronomic practices applied in these agroecosystems, the study aimed to compare the soil quality and identify the system with the least impact on soil biodiversity conservation, with the goal of laying the basis for identifying soil quality benchmarks within each system to be used in monitoring activities in land protected areas. Results showed that organic farming combined with land protection had a positive impact on soil quality. The overall soil quality was excellent, with the highest levels found in arable lands. This is consistent with the intermediate disturbance hypothesis (IDH), which states that slightly disturbed habitats (i.e., arable land with minimum tillage) tend to have higher organism diversity than stable ones. The composition of microarthropod communities in arable land differed from those in stable arboreal crops. Olive groves showed a higher abundance and diversity of microarthropods compared to vineyards, which showed lower values. Promoting the use of QBS-ar, identifying benchmarks for prevalent agroecosystems, and ensuring continuous monitoring of protected areas are thus crucial issues.