Effect of land-use types on edaphic properties and plant species diversity in Mediterranean agroecosystem

Land-use intensification, contrary to sustainable land management, has an impact on the healthiness of the environmental agroecosystem. To assess the environmental implications in abandoned land, olive groves and maize crops, the most sensitive and reliable edaphic indicators were measured to estimate plant species diversity and potentially toxic elements in soil, among different types of land-use. Species diversity presents a decrease in maize crops and olive groves compared to abandoned land. The families with the greatest species diversity were Poaceae, Asteraceae and Fabaceae in each land-use. From the results of the canonical correspondence analysis among species, sampling sites and selected environmental variables, a clear separation between species and sampling sites belonging to different types of land-use was found, presenting strong correlation with specific edaphic parameters (pH, Soil Organic Matter, Silt, Electrical Conductivity, Total Nitrogen, ${NO}_3^{-}$ , P, K, Zn and Cu). Species diversity was reduced in maize crops due to anthropogenic interventions such as the excessive use of nitrogen and phosphate fertilizers and herbicides. Despite the fact that the lowest richness of plant species was found in olive groves, non-removal of crop residue preserves soil organic matter. In 7.4% of soil samples in olive groves, ${\mathrm{Cu}}_{\mathrm{total}}$ concentrations were over 100 mg kg^-1 denoting polluted soils, while the potentially toxic concentrations of bioavailable copper fraction ( ${\mathrm{Cu}}_{\mathrm{DTPA}})$ probably lead to a decrease of species diversity. Future researches should therefore focus on the accumulation of toxic elements in agricultural land to preserve species diversity and a healthy environment.