EXPLOITATION AND CONSERVATION OF IRONWOOD (OLNEYA-TESOTA) IN THE SONORAN-DESERT

An increasing trend in desert ironwood (Olneya tesota) exploitation in Sonora has affected the population structure, growth, and recruitment of this species near the Gulf of California in the Sonoran desert. In a survey of protected and unprotected sites in Mexico and the United States, we determined that the damage has resulted in a significant re duction in the amount of shaded area for the plant communities. Exploi tation is highest in the Mexican stands near the international border, but high basal area percentages of damaged trees were detected in pro tected areas in both the United States and Mexico. One area of particu lar interest is the administrative boundary of the Organ Pipe Cactus N ational Monument (ORPI) with Mexico, where harvesting of ironwood in t he border creates a boundary effect with the ironwood populations that inhabit both sides of the ORPI border. Harvesting of ironwood is for firewood, charcoal, and wood carving.