Growth and yield of Retrophyllum rospigliosii pure plantations in the Colombian Andes

Abstract

Most reforestation in Colombia, especially in the Andean region, are monocultures of pines and eucalyptus with defined nursery and silvicultural packages. Planting native species would avoid the widespread controversy over reforestation with exotic species. Nevertheless, there are few studies that evaluate the growth and yield of native species and provide supported data to establish new projects. Here, we modeled the growth and yield of the native coniferous Retrophyllum rospigliosii in different areas of the Colombian Andes in terms of mean diameter (D), height (H), and volume (V) as a function of age, based on longitudinal data from 115 research sample plots from three sites that were remeasured between 4 and 9 times for 20 years. We fitted the von Bertalanffy growth model for D, H, and V through Bayesian generalized nonlinear mixed models to model tree growth. The adjustment of the models for the absolute growth of R. rospigliosii was 0.99, 0.99, and 0.97 for D, H, and V, respectively. All models fulfilled all regression assumptions. Although the growth rates of R. rospigliosii differed between planted sites, R. rospigliosii plantations generally exhibited low growth and barely reached the sizes required for commercialization. These results suggest that the extensive use of R. rospigliosii in pure plantations is unlikely and discourages the massive propagation of R. rospigliosii.