Vegetative Changes on Protected Versus Grazed Desert Grassland Ranges in Arizona

Abstract

Comparison of vegetative changes between a protected and closely grazed desert grassland range in southeastern Arizona showed that velvet mesquite was rapidly invading both ranges at almost equal rates. Arizona cottontop, sideoats grama, and wright buckwheat were dominant in the understory on the protected range while rothrock grama, poverty threeawns, burroweed, and annuals dominated the understory on the grazed range. The grazed range was classed in a low stage of range condition, the protected range in an intermediate stage. Without a change in treatment and management, it is postulated that mesquite will continue to increase on both ranges.