Slash and litter management effects on Eucalyptus productivity: a synthesis using a growth and yield modelling approach.

Within the context of sustainable management of forest ecosystems, a network was started by the Center for International Forestry Research in 1995 to evaluate the impacts of slash management practices on the productivity of eucalypt, acacia and pine plantations. This network has now reached one full rotation for the ten eucalypt sites in Australia, Brazil, China, Congo, India and South Africa. This paper reports an overall synthesis of tree and stand growth. Using a growth and yield modelling approach, we investigated the effects of slash management on site index defined as the asymptotic dominant height, basal area growth and stand structure. There were significant effects of slash and litter management treatments on two processes that drive tree and stand growth: site index and ability of trees to capture the site potential. These impacts were strongly site dependent. As expected, the soil organic carbon concentration could not be used alone to predict the intensity of stand response. Conversely, a ratio between nitrogen content in slash and litter prior to planting and the nitrogen concentration within the 0-10 cm soil layer, was a good predictor of the differences in stand productivity across treatments. (Resume d'auteur)