Early detection and trend detection of invasive non-native plant species comprise two of the Sonoran Desert Network Inventory and Monitoring Program's vital signs. Baseline information on the presence, location, and abundance of invasive non-native plant species is necessary to accomplish two goals: (1) to identify which invasive non-native species are not yet present in the park (early detection monitoring); and (2) to map the spatial location, distribution, and abundance of those species that already occur in the park as the basis for future trend assessment.