Site quality, growth and yield, and growing space occupancy by plantations of Pinus caribaea var. hondurensis in Oaxaca, Mexico.

摘要

The data of these studies came from permanent sample plots and stem analyses in plantations of Caribbean pine in savanna areas of Oaxaca.; A set of anamorphic site index curves was developed at base age of 15 years. The algebraic difference approach and the Chapman-Richards model were used. There was actually little variation in site index in the observed population.; Another part of the investigation on site quality consisted in relating physiographic and edaphic characteristics to site index. The only physiographic feature that showed significant effect in the variation of site index was aspect. Soil properties that contributed significantly to the variation in height growth of dominant trees were silt percentage, total nitrogen, organic matter content, and moisture content at field capacity.; The growth and yield study was conducted using a diameter distribution technique. The Weibull function was used to model the diameter distribution of the sample plots. Weibull parameters were estimated based on the 24th, 50th, and 93rd sample percentiles. The parameters were related to stand characteristics, and in turn, these were projected as a function of stand age, allowing recovery of the function parameters, in order to recreate the diameter distribution at the end of each forecasting interval.; Growth and yield were projected from 10 to 40 years. An individual tree height equation, and several volume tables were developed to compute volumes by diameter class at the end of each projection period. Mean annnual increment in total merchantable volume peaked at age of 27.5 years (16.2 m3/ha/yr, approximately) in the typical sample plot used to exemplify how the growth model works.; A stocking guide using the three-dimensional relationship between crown volume and bole volume was also constructed. This guide will allow for prescribing thinning schedules, according to the growing space required to grow trees to certain size.; The effiency of volume production per unit of crown projection space occupied increased with increasingly high crown class. This efficiency did not vary with the small differences in site quality.