Riserve di carbonio, forme di humus e qualità biologica in suoli forestali sardi

This work concerns the development of new methodological approaches at different ecological scales to evaluate the quality of the forest soils. The study was carried out in four sites: Monte Ferru, Timidone, Ugolio, and Pixinamanna. Three approaches were considered that focus on: <br>- the soil as a <i>habitat</i> for the micro-edaphic fauna (microscopic scale), with particular reference to the method QBS-ar;</br> - the properties of forest humus and the forest soil as a carbon sink (stational scale); <br>- the hydro-ecological functions performed by the soil along the slope, according to the LFA (Landscape Function Analysis) method. Within each study area soils were sampled for laboratory analysis and for the analysis of microarthropods, and the forest humus were classified. The LFA method has been applied only in the Pixinamanna site.</br> The largest organic carbon content was observed for the sites not subjected to recent disturbances. The most common humus is the <i>Amphimull</i>, a humus form typical of the Mediterranean environments characterized by bimodal rainfall. The QBS-ar index showed higher values for situations in which the disturbance factors were removed in remote times, and lower values with higher human impact. The LFA highlighted the different ecological performance of the studies formations. <br>An <i>olistic</i> quality index was defined according to the <i>minimum dataset</i> and the <i>linear scoring</i> approaches, to define and compare the overall quality of the studies forest soils.</br>