Population Structure of Maguey ( Agave salmiana ssp. crassispina ) in Southeast Zacatecas, Mexico.

A study was performed from May 2001 to October 2002 to assess density and morphological characteristics of maguey, Agave salmiana ssp. crassispina, in five districts of the state of Zacatecas, Mexico. A random stratified sampling procedure was used, where each area with different maguey densities (high, moderate, low, and very low) was treated as an independent stratum. Then, 154 randomly distributed sites covering an area of 250 m 2 were evaluated obtaining the following data: number of individuals by age class (juvenile, prereproductive, reproductive, and mature), height, crown width, and basal diameter. Thematic maps as well as aerial photos and field visits were utilized to produce a base map, which was digitized, vectorized, and georeferenced using GIS tools. The total area occupied by maguey populations was 59,905 ha. Mean densities were as follows: 1,142 ha with 3,064 magueys per ha; 17,441 ha with 892 magueys per ha; 34,088 ha with 725 magueys per ha; and 7,234 ha with 653 magueys per ha. There were differences in age class, height, crown width, and basal diameter between strata as well among strata. The data suggested that different management programs must be used to ensure sustainability of this resource. [ABSTRACT FROM AUTHOR]