The influence of silvicultural practices on resin production: stand density, tree diameter, and use of controlled fire
Some aspects contribute to the increase of resin tapping costs and, hence, to the reduction of resin yield, namely: the limitation on the diameter of the trees to be tapped imposed by the Portuguese legislation; low stand densities; the necessary control of understory vegetation. Hence, it is essential to evaluate if and how some pine forest management parameters affect the total production of pine resin so it can be increased through silvicultural practices and, thus, compensate for the rise in some costs associated with the resin activity.
- Evaluate the influence of tree size, stand characteristics, debarking coefficients and climatic variables on cork thickness and its evolution between consecutive cork extraction operations, i.e. between successive cork growth periods (cgp). Cork growth is assessed using the cgi, defined as the radial width of the first eight complete years of cork growth after stripping.
- Assess the impact of the increase in debarking intensity on cork growth. Debarking intensity is quantified by the cork debarking coefficient – the ratio of the vertical debarking height to the perimeter at breast height, measured over cork.