Does the application of silvicultural management models drive the growth and stem quality of sweet chestnut coppices towards sustainability?

Abstract

The coppice is a very flexible cultural system producing several calibers adapting to the demands of the market. Small-caliber roundwood from sweet chestnut (Castanea sativa Mill.) coppices, formerly in great demand, is now less interesting for the market. Thus, the improvement of coppices management by applying alternative silvicultural models in order to obtain benefits and sustainability is essential. For this purpose, four permanent plots (P1-P4) were established in 1994 to monitor different coppice management systems. The plots were installed in a coppice which resulted from the final clear cut of a sweet chestnut high-forest stand in 1992, at 50 years old. Three silvicultural management models were tested in order to produce roundwood of small (P1), medium (P2), and large (P4) diameters. A control plot was established without any type of silviculture which corresponds to most of the existing chestnut coppices (P3 = without intervention). Thinnings were applied in the plots according to the respective management model. Twenty-four years after the sprouting of the coppice, the silvicultural models were evaluated according to their objectives in terms of growth, yield, and quality of the sawlogs. This assessment period corresponds to the end of the rotation period for P1, and the results are in accordance with expected values. In P2 and P4 the observed growth closely matches expectations for this growth stage of the coppice. The quality of the sawlogs is clearly superior to that of the plot without intervention. Comparing the mean dendrometric values, higher values were observed in plots where the models were applied. The results also show that when roundwood is used for saw-timber, silvicultural management is essential.