Surface morphology and thinning grade effects on soils of a Calabrian Fine plantation in the Sila Mountain (Calabria, Italy)

Abstract

Important reafforestation programmes of the Sila mountain with the main purpose of soil conservation and hydrogeological control started in 1955. Interactions with the soil and surface morphology have been studied in a plantation of Pinus nigra var. calabrica Schneid. where a field trial was carried out to establish the optimum thinning rade from an economic point of view. The experimental area is sited near Camigliatello Silano, at 1247 m above sea level, on soils derived from granite and granitic saprolite. Soil profiles were dug and completely analysed in eight selected sites. At each plot, colour, organic matter, depth and texture of all the soil horizons, as well as slope and exposure were measured. Pedological investigation results indicate that soil varies considerably between different plots according to the degree of its evolution, thus three main types of soil have been identified. Quite a rapid development of the umbric horizon, somehow depending on slope, exposure and thinning grade, has been recognised. In this sense the negative effects of a slope gradient exceeding 25% and southern facing exposures come out clearly, whereas thinning doesn't seem to affect soil conservation, even when somewhat heavy thinning grades are utilised.