Application of a Process-Based Model for Predicting Aboveground Biomass of Eucalyptus Globulus Bioenergy Plantations in Southern Chile
An alternative to reduce the impact of climate change is to reduce emissions of greenhouse gases through the use of alternative renewable and low cost energy as those based on biomass transformation, specifically dendroenergy Plantations. Operational crops from this kind are still scarce due to the lack of relevant information in terms of expected returns and silvicultural activities under different management schemes and weather conditions Ecophysiological process-based models for predicting productivity of forest plantations from the efficient use of solar radiation, determined by specific parameters for each species and weather information. The 3-PG model (Physiological Principles Predicting Growth) has proven accurate estimates on plantations of genus Eucalyptus, however, are scarce experiences of using this model in dendroenergetic plantations of high density, its parameterization could allow to estimate more certainty productivity in this type of site-specific plantations under different management schemes level. The general objective of this study was to evaluate the efficiency of 3-PG model in aboveground biomass prediction of E. globulus of a dentroenergetic plantation undergoing intensive silviculture in order to identify the full potential of biomass production. Two contrasting sites were examined from south central Chile (soils of volcanic sands and recent volcanic ash) and three levels of density were evaluated (5000, 10000 y15000 trees ha-1) The 3PG model was successfully parameterized and contrasted with field observations, a high level of efficiency (97% average) for the variables evaluated (total, stem and foliar biomass,) was observed. It was identified that the highest cumulative aboveground biomass occurred in establishment density of 10000 and 15000 trees ha-1, independent of the year in which decides culminate the rotation. In both densities, it is observed that sandy soils achieve a maximum monthly mean increase in aboveground biomass before two years (3-5 Mg ha-1 month-1), in contrast to volcanic ash soils achieve maximum mean monthly aboveground biomass increment at 4 years (1.5-2.5 Mg ha-1 month-1). Finally, the maximum accumulation in aboveground biomass for a 4-year rotation occurs in soils of sandy type with an initial density of establishment of 10,000 trees ha-1 for a rotation of 5 or 6 years the maximum accumulation takes place in volcanic ash soils established at densities of 15,000 trees ha-1.