Riparian Mesquite Forests: A Review of Their Ecology, Threats, and Recovery Potential

Stromberg, J.

Mesquite (Prosopis spp.) forests, or bosques, historically represented one of the most abundant riparian communities in the southwest, but are reduced to remnant status. They occur on high floodplains elevated 2 to 15m above the water table, within riparian ecosystemsthat historically spanned widths of several kilometers and stretched for hundreds of kilometers along the lower reaches of southwestern rivers such as the Gila and Colorado. Bosques today are much reduced in size and and are composed of dense stands of trees that are younger and smaller than their potential size of 18 m in height and 1.5 m in stem diameter. The canopy layer of bosques is dominated by mesquite soecies, but the understories can support a diverse assemblage of shrubs, vines, and herbaceous plants. The mequite trees have high productivity because of the combination of a deep root system that extends nearly to the riparian water table and of symbiotic associations with nitrogen-fixing bacteria. This productivity is expressed, in part, in the production of abundant flowers and fruit. This, in turn, allows for diverse and abundant animal life, and is one of the reasons why mesquite bosques support one of the highest densities of breeding birds of nay southwestern habitat. Bosques today continue to be threatened by many human activities including groundwater pumping and surface water diversion; land clearing and wood cutting; and land uses such as livestock grazing. Attempts have been made to restore mesquite bosques but the limited success of most of these projects highlights the need to protect remaining bosques.

Riparian Mesquite Forests: A Review of Their Ecology, Threats, and Recovery Potential

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