COMPARISON OF WOOD VOLUME ESTIMATORS IN MEDIUM HEIGHT TROPICAL FORESTS OF MEXICO

Abstract

In Mexico, the project National Forest and Soil Inventory (Inventario Nacional Forestal y de Suelos-NFyS) uses ratio estimators that are easily applicable for statistical analysis of dasometric data. However, under diverse circumstances, it may be impossible to obtain data that fully comply with their theoretical assumptions. In this study, the results of the INFyS ratio estimator are compared with results using alternative estimators. With 2010 data from the sampling grid obtained in the medium height sub-evergreen and subdeciduous forests of Quintana Roo and Campeche, Mexico, the ratio of means estimator, mean of ratios estimator and the Forest Inventory and Analysis (FIA-USDA) were compared statistically. The relative bias of the ratio estimator (bias, relative to the standard error) in all cases was below 10% and, therefore, considered insignificant. Under the conditions of this study, the results indicate that the three estimators are not statistically different. However, the mean of ratios estimator has the advantage of directly providing estimations per hectare. Moreover, its theoretical approach permits its analysis from a perspective of the Horvitz-Thompson estimator.