Ecological Relationships between Pinyon-Juniper and True Mountain Mahogany Stands in the Uintah Basin, Utah

Abstract

Ecological relationships between true mountain mahogany and pinyon-juniper stands in the Uintah Basin, Utah, were measured to detect differences between the two community types. The mountain mahogany community is dominated by grasses and shrubs, while the pinyon-juniper vegetation consists primarily of trees and annual plants. Soil depth is greatest in the pinyon-juniper areas. Slickrock often covers as much as 80% of the mountain mahogany stands. Soil was sampled from beneath and between the mahogany shrubs and the pinyon and juniper trees. The pH of soil from beneath mahogany shrubs was significantly (P < 0.001) more alkaline than that from beneath pinyon and juniper trees. Soluble salt concentration was significantly (P < 0.05) less in soil from beneath mountain mahogany shrubs than in soil from between shrubs. A reverse situation occurred in the pinyon-juniper stands.