Soil degradation by land use change in an agropastoral area in Sardinia (Italy)

Abstract

In recent decades the clearing of Mediterranean maquis along with the creation of new pastures has been a major factor of land degradation in Sardinia (Italy). This was due to an inadequate implementation of agricultural policies. Consequently, tillage and water erosion intensified over a wide area. The present work assesses the impacts of land use change on soil properties in a representative area of central-eastern Sardinia. Paired forest and pasture sampling sites were selected in relation to present land use, land suitability, and land use history. Different soil properties were considered: physical (sand, silt, clay, soil thickness, bulk density, and penetration resistance), chemical (pH, OC, N, C/N, Ca, Mg, Na, K, CEC, and BS), biological (BQI), and micromorphological (microporosity and microstructure). The comparison of forest and pasture soils showed a significant soil loss (in terms of soil thickness, −22%), and a clear decrease in organic carbon storage (−64% on average). An increase in bulk density (+ 44%) and a change in microporosity and its vertical distribution were also observed, respectively by field measurements and micromorphological quantification on digital images.