Velvet mesquite thinning to improve riparian forests

Abstract

Velvet mesquite (Prosopis velutina) in riparian settings is known for developing bosques, stands of mature trees with an open understory that supports other native plants and wildlife. Many historic mesquite bosques in the Madrean Archipelago have been cleared to allow farming on river floodplains. In some cases, cultivation of those farm fields was later abandoned, leading to a rapid recolonization by mesquite. The result has been dense stands of small mesquites, all competing for limited soil moisture and groundwater supply. We looked at the possibility of advancing one of those stands toward the structure of a mature community by an experimental thinning program. A treatment plot was thinned from 2,683 to 542 trees ha-1 (1086 to 219 trees ac-1). During the first two years, stem diameters increased 67% faster in the thinned area than an adjacent control plot. After 19 years, the thinned plot still showed a more open stand structure and had a taller canopy than the control plot. However, resprouting of some cut trees affected results in basal area and area at breast height, so success of the effort would likely have been greater with some follow-up treatment. Based on these results, it appears that thinning dense sapling stands can produce significantly higher growth rates in the remaining trees, accelerating the transition to open stands of large trees that might provide better habitat for other species.

Parent Publication

• Collaboration Now for the Future: IV Conference on the Biodiversity and Management of the Madrean Archipelago

Citation

Turner, Dale S.; Gori, David F. 2022. Velvet mesquite thinning to improve riparian forests. In: Neary, D. G.; Gottfried, G. J., eds. Collaboration Now for the Future: IV Conference on the Biodiversity and Management of the Madrean Archipelago. Proceedings RMRS-P-79. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 131-135.