PARENT SESSION
Tuesday, August 8, 5:00-6:30 pm
Poster Session 9 - Restoration and conservation ecology and ecosystem management
Exhibit Hall, Ballroom Level, Cook Convention Center

Modeling revegetation success after tamarisk (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) removal in the southwestern, US.

Bay, Robin¹, Meehan, Margaret^*,1, Sher, Anna^{1, 2}, ¹ University of Denver, Denver, CO² Denver Botanic Gardens, Denver, CO

ABSTRACT- Invasion of watersheds by non-native woody species including tamarisk (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) has made habitat restoration projects necessary to maintain the ecological integrity of many riparian communities in the Southwest. These restoration projects may include removal, manipulation of hydrographs, and active revegetation with natives. There is no single strategy for achieving success in these projects; rather success will vary by site based on specific site characteristics and methods used. In a study initiated in summer 2005, plant species diversity and vegetative cover were evaluated at over 28 sites in New Mexico, Arizona, and Nevada where active revegetation occurred after invasive removal. These data were incorporated into regression tree models with years since removal, and multiple management, climate, soils, and hydrologic variables to look at success of native plant communities, control efforts, and revegetation success. Results suggest that increased soil drainage and decreased salinity as well as close distance to water and moderate maximum temperatures are important factors for increased native plant community diversity and cover. Additionally, tamarisk and other noxious weeds are most persistent in dry, basic soils where competition from native species is limited. These quantitative models are intended to assist researchers and land mangers in the future to design more effective riparian restoration efforts in this critical arid lands ecosystem.

Key words: restoration, invasion, riparian