Studio della componente organica del suolo di faggete trentine in relazione al trattamento selvicolturale

Investigation on soil organic component and its relationships with silvicultural regime in beechwoods (Tren­ tino, Italy). Since the last 50 years, areas where beech coppices remain unmanaged are increasing in Italy. In more recent years some of these coppices underwent conversion to high-forest. Little information exists on the consequences of this management choice for ecosystem properties, such as soil organic matter and soil humic substances. This study consists in a quantitative and qualitative characterization of soil organic matter as a function of different management and pedoclimatic conditions in beech coppices in Trentino, Northern Italy. The study was conducted in four beech coppices, two calcicolous mesic typical beech forests and two calcicolous xeric beech forests. For each forest type we selected one unmanaged coppice (over the last 40 years) and one coppice stand converted to high forest by releasing a limited number of standards. The quali­ tative features of humic substances were examined through gel-filtration and Diffuse Reflectance Infra Red Spectroscopy. Results show that the two types of forest respond in a different way to the conversion treat­ ment. In mesic beech forest, humification parameters appear to slow down after silvicultural treatment; in xeric beech forest, a stronger polycondensation of humic compounds was observed after the silvicultural treatment.