Thursday, August 9, 2007

PS 68-199: Environmental factors assessment of the Station of Ecologic Restoration in Barrancas del Río Tembembe, central Mexico

Juana García-Flores1, Jorge López-Blanco1, María del C. Bonfil- Sanders2, and Rosa I. Trejo-Vázquez1. (1) Instituto de Geografía, UNAM, (2) Facultad de Ciencias, UNAM

An environmental evaluation that integrated relief, vegetation and soil factors was conducted to obtain knowledge of biophysical interactions in the Station of Ecologic Restoration (SER) Barrancas del Río Tembembe, in Central Mexico. Natural units were delineated to determine restoration-conservation strategies in the study area which is located in the NW area of the State of Morelos at elevations from 1,500 to 1,700 masl. It extents 97 ha where induced grasslands prevail and only remnants of tropical dry and oak, forests persist. Geomorphologic and Land Cover Units Maps were constructed at a detailed scale (1:20,000). Systematic samplings in five transects transverse to the main river channel trajectory were surveyed every 400 m at the North to South bearing in order to; (1) To identify geomorphologic processes and morphological characteristics of the relief, and (2) To collect soil samples in order to obtain physical-chemical properties. As a result, eighty-four geomorphologic units and ninety-eight Land Cover units were delimited. The soil properties throughout the study area were analyzed by spatial distribution using standard interpolation techniques. The environmental factors were overlaid on the Geomorphologic Units Map in order to obtain the natural or biophysical, units at the SER. The cluster analysis of the natural units revealed that the Relief position is the most important variable, and the principal component analysis indicated a relationship between the Relief position, Land Cover types and Soil characteristics. The medium and lower parts of volcanic-ravine backslope, and the volcanic-ravine footslope are considered of high-priority areas for conservation due to their specific characteristics and because they maintain natural vegetation, while the summit, shoulder and the upper backslope of the volcanic-ravine should be considered as restoration areas focusing to increase the vegetation cover to reduce erosion processes.