%0 Journal Article
%T Modeling Growth and Yield of Schizolobium amazonicum under Different Spacings
%A Gilson Fernandes da Silva
%A Salvador Alejandro Gezan
%A Carlos Pedro Boechat Soares
%A Luciano Zumerle Zaneti
%J International Journal of Forestry Research
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/675137
%X This study aimed to present an approach to model the growth and yield of the species Schizolobium amazonicum (Paric¨¢) based on a study of different spacings located in Par¨¢, Brazil. Whole-stand models were employed, and two modeling strategies (Strategies A and B) were tested. Moreover, the following three scenarios were evaluated to assess the accuracy of the model in estimating total and commercial volumes at five years of age: complete absence of data (S1); available information about the variables basal area, site index, dominant height, and number of trees at two years of age (S2); and this information available at five years of age (S3). The results indicated that the 3 ¡Á 2 spacing has a higher mortality rate than normal, and, in general, greater spacing corresponds to larger diameter and average height and smaller basal area and volume per hectare. In estimating the total and commercial volumes for the three scenarios tested, Strategy B seems to be the most appropriate method to estimate the growth and yield of Paric¨¢ plantations in the study region, particularly because Strategy A showed a significant bias in its estimates. 1. Introduction In the past, logging of high-grade trees in Brazilian natural forests occurred in an unplanned and predatory way. At present, the trend is toward increasingly rigorous environmental legislation to prevent illegal harvesting of natural forests. In Brazil, most wood still comes from native forests. Companies that produce pulpwood and fuelwood constitute a minor part of the total timber production and often fill their needs with their own supply. In contrast, companies that produce sawtimber and plywood correspond to a large proportion of the total production and usually require wood from native forests. The increasing difficulty removing wood from native forests due to legislation or supply has resulted in some companies beginning to produce high economic value species through commercial plantations. However, little is often known about the silviculture of some of these native species, and it is typically difficult to find improved genetic material for high yields and more homogeneous forests. One attractive native species that has been planted in recent years due to its favorable characteristics is Schizolobium amazonicum Huber ex Ducke, known in Brazil as Paric¨¢. This species has rapid growth, a straight bole, natural pruning, and highly valued wood in domestic and foreign markets [1, 2]. Paric¨¢ has been widely cultivated by timber companies in the northern and northeastern regions of Brazil, mainly in the
%U http://www.hindawi.com/journals/ijfr/2013/675137/