Soil characteristics in semiarid highlands of central Mexico as affected by mesquite trees (Prosopis laevigata)

In the semiarid highlands of central Mexico the mesquite tree (Prosopis lae vigata) is often removed for agricultural and forestry purposes. Clearing o f 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 t hree distinct locations: under the canopy of the mesquite tree, in the area surrounding the mesquite tree but not covered by its canopy, and in adjace nt 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 mes quite tree than in the surrounding area and in the adjacent arable soil.