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

Abstract

In the past centuries a notable reduction of lowland forests in Italy was detected as a result of the spreading of intensive agriculture and deforestation activities. According to the national forest inventory (INFC 2005) the English oak (Quercus robur L.) is mainly a scattered species and is distributed across 146,000 hectares of mixed forests. However this species has often been used in many national programs to recreate new woodlands in the lowlands as well as tree farming plantations. In the '80s, during the restoration program of the Santa Barbara mining area in the Municipality of Cavriglia (Valdarno, Tuscany), about 172 hectares of tree farming plantations 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 trees was measured using the Heyer formula and a volume 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 m3 corresponding to a relative RMSE of 10%.

Keywords

• volume equation, tree farming plantation, English oak, Valdarno