Deep-planting methods that require minimal or no irrigation to establish riparian trees and shrubs in the Southwest

Excerpt

During the past 20 years, the Los Lunas Plant Materials Center (LLPMC), USDA Natural Resources Conservation Service, has developed deep-planting techniques that require minimal or no follow-up irrigation to establish woody vegetation on disturbed riparian sites in the arid and semiarid Southwest. The use of these techniques results in minimal maintenance and high survival rates, which will reduce ultimate revegetation costs. Invasive exotic woody species, primarily saltcedar (Tamarix sp. L.) and Russian olive (Elaeagnus angustifolia L.), have been controlled on floodplain tracts totaling more than 13,750 ha (34,000 ac) along New Mexico's major rivers during the past five years by mechanical extraction or herbicide application (New Mexico Department of Agriculture 2005). Principal motives for these efforts include conserving groundwater, reducing wildfire potential, restoring wildlife habitat, and providing grazing or other beneficial uses. The alteration of surface and groundwater hydrology by flood control structures and flow regulation has encouraged the spread of invasive woody species (Stromberg et al. 2007) and has resulted in relatively deep water tables on many sites. The lack of overbank flood events on these rivers has perturbed normal ecosystem function and prevented the natural recruitment of native species comprising the gallery forest and its understory vegetation. The …