TABLAS DE PRODUCCIÓN PARA EL INVENTARIO DE CORTADILLO (Nolina cespitifera Trel.) EN EL SURESTE DE COAHUILA

Abstract

Cortadillo (Nolina cespitifera) is a non-timber forest resource of the arid and semiarid zones of Northeastern Mexico, speci cally of South Coahuila and Nuevo Leon states and the Northern part of the state of Zacatecas. Fiber obtained from the leaves of this plant is used, combined with tassels of sorghum, to manufacture brooms. The objective of this work was to validate an existing production tariff and to develop tables for cortadillo leaf production by type of vegetation: rosetophyllous desert scrub, grassland-yucca transition, pine-oak forest and oak forest. 600 plants was sampled along all vegetation types and the following statistical analyses were performed: homogeneity of variances, homogeneity of means and a comparison of the slope of the previously existing model versus the one generated with our data from the sampled plants, as well as with the slope of models generated for the plants of each vegetation type. Preliminary results showed that the model required to be adjusted and that tables of production needed to be developed for each vegetation community. These tables were generated by means of regression analyses and correlation, with fresh weight of leaves as the dependent variable, and height of plant, mean basal diameter, basal area, and volume as independent variables. Models were selected based on analysis of variance, maximum determination coef cient, minimum mean square of error and minimum variation coef cient. Resulting models were: Y = 0.18487(Vol)0.6552 (rosetophyllous desert scrub), Y = 0.05573(Vol)0.7 51 (grassland-yucca transition), Y = 0.00958(Vol)0.90 1 (pine-oak forest) and Y = 0.1016(Vol)0.7506 (oak forest).