Lake Mead National Recreation Area Vegetation Monitoring and Management: Year-End Progress Report, October 1, 2007 to September 30, 2008

摘要

Executive Summary The Weed Sentry program surveyed over 335 miles and 2,610 acres of transportation corridors on federal land in Clark County for incipient populations of exotic plants. 18 manuscripts attained in-press or published status and one manuscript was submitted for review this year. Among published manuscripts, are one documenting Sahara mustard germination patterns (Western North American Naturalist), one assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), and another is a synthesis of burro effects on Mojave Desert vegetation (Environmental Management), and one assessing vegetation in grassy remnants of the Las Vegas Valley (Desert Plants) Staff delivered 19 presentations this year at conferences, university lectures or agency meetings. The Weed Sentry program concluded data collection on a major assessment of the condition of 12 remote springs, with particular reference to the presence of exotic species, on the Fish and Wildlife Service’s Desert National Wildlife Refuge. Four presentations were delivered by Research Assistant Cayenne Engel and Dr. Scott Abella at the widely attended 9th Biennial Conference of Research on the Colorado Plateau. These presentations included three invited presentations for a special revegetation session. Two of the presentations were co-delivered with NPS ATR Alice Newton. A total of 13 permanent sites were established and sampled as part of a microhabitat and distance-from-road invasibility study. Jill Craig initiated a community invasibility study to try and determine factors regulating exotic species invasion following disturbance. Alex Suazo initiated a series of experiments on Brassica tournefortii seed ecology including the role of rodent seed distribution and the effect of disturbance and water additions on insitu seed germination. UNLV M.S. candidate Chris Roberts conducted a major resampling effort of the 1979 Holland Plots in the Newberry Mountains. A total of 106 plots were resampled, and data analysis is in progress.