干旱区生态环境知识资源中心

In the semiarid highlands of central Mexico the mesquite tree (Prosopis laevigata) is often removed for agricultural and forestry purposes. Clearing of land for agricultural purposes has a significant impact on soil processes and nutrient dynamics and, ultimately, on crop production. We have studied the effect of the mesquite tree on soil respiration, amounts of bacteria, fungi, and actinomycetes, and soil characteristics. Soil was sampled from three distinct locations: under the canopy of the mesquite tree, in the area surrounding the mesquite tree but not covered by its canopy, and in adjacent cultivated land. It was found that the mesquite tree plays an important role in nutrient cycling in arid and semiarid regions. Soil microorganisms and nutrients (N, P, and Fe) were more abundant under the canopy of the mesquite tree than in the surrounding area and in the adjacent arable soil.