Management tools for Castanea sativa coppice stands in northwestern Spain

Abstract

The importance of chestnut coppice stands in northwestern Spain, together with the almost total lack of growth and yield studies, makes the development of applicable tools to facilitate forest management necessary. In the present study two management tools were developed: variable-density yield tables and stand density management diagrams (SDMDs). For constructing the yield tables, a dominant height growth model and a stand density model were fitted. The dominant height growth model was necessary for estimating site index, i.e., for indirectly assessment of site quality. A stand density model was necessary because the silvicultural stages of the stands were very heterogeneous. Both yield tables and SDMDs require fitting models for predicting quadratic mean diameter and growing stock (total or merchantable stand volume and/or total or component stand biomass). Eight yield tables were constructed considering two stand density levels (high and low) and four site indices (8, 12, 16 and 20 m). Rotation lengths producing maximum sustainable yield ranged between 25 and 45 years depending on stand density class and site index. Average growth at these rotation lengths varied from 38.1 m³ ha^-1 year^-1 for the highest density and best quality, to 5.2 m³ ha^-1 year^-1 for the lowest density and poorest quality. Both the yield tables and the SDMDs developed allow estimation of total and merchantable stand volume, total and component stand biomass and also facilitate the design of silvicultural schedules.