Volume function for the tree farming English oak plantations of the Valdarno (Tuscany, Italy)

Abstract

In the past centuries a notable reduction of lowland forest s in Italy was detected as a result of the spreading of intensive agriculture and deforestation activities . According to the national forest inventory (IN F C 2005 ) the English oak ( Quercus robur L.) is mainly a scattered species and is distributed across 146,000 hectares of mixed forests. However th is species has often been used in many national programs to recreate new woodland s in the lowland s as well as tree farming plantations. In the '80s, d uring the restoration program of the Santa Barbara mining area in the Municipality of Cavriglia ( Valdarno, Tuscany), about 172 hectares of tree farming plantation s were created with English oak . Due to the lack of a specific volume equation for Italian plantations a sampling campaign was carried out. The volume of 299 sample tree s was measured using the Heyer formula and a v olume equation was studied as a polynomial function of DBH and total height of trees . The final equation demonstrated to be quite robust with a RMSE of 0.0176 m 3 corresponding to a relative RMSE of 10%.