EXPLORING THE SUSTAINABILITY OF CURRENT MANAGEMENT PRESCRIPTIONS FOR PINUS CARIBAEA PLANTATIONS IN CUBA: A MODELLING APPROACH

The ecosystem model FORECAST was used to evaluate the sustainability of current management practices in Pinus caribaea plantations in Pinar del Río (western Cuba). Model predictions were within the range of observed field measurements of height, diameter, stem density and volume. The model performed reasonably well in capturing general growth trends (r values for dominant height, diameter and merchantable volume were 0.91, 0.77 and 0.81 respectively). In the second part of our work, model output of merchantable volume, stem biomass, soil organic matter and available N in soil were analysed in 18 different combinations of rotation length (25 vs. 50 years), thinning intensity (0, 15 and 30% stems) and fertilisation (0, 50 and 100 kg ha-1 N) in order to study the effects of different management regimes on site fertility. Our results indicated that some of the current prescriptions could produce a considerable loss of nitrogen, and in some cases, a decrease in productivity after the third 25-year rotation. However, other prescriptions can keep productivity and soil organic matter at acceptable levels. The results of our analysis illustrated the portability and utility of FORECAST as a scenario-analysis and decision-support tool in managing pine plantations in the Caribbean region and, potentially, elsewhere.