Lake Mead National Recreation Area Vegetation Monitoring and Analysis: Quarterly Progress Report, Period Ending March 31, 2007

Executive Summary Weed Sentry staff surveyed for exotic species on 208 miles of roads on NPS land and on 61 miles of BLM land. Due to sparse precipitation this winter, exotic species are much less abundant this year compared to last year at this time. Other exotic species projects initiated this quarter included an assessment of invasion patterns below native shrubs for early detection of potential invasion “hotspots,” and a community invasibility experiment established near the NPS nursery with substantial involvement from NPS ATR Ms. Alice Newton. A manuscript detailing several experiments with the invasive species Sahara mustard was submitted for peer review to the journal Western North American Naturalist. Two synergistic projects undertaken this quarter at the request of NPS ATRs included a barrel cactus reassessment and a monitoring study of vegetation manipulations at two springs. Another synergistic project entailed several plant salvages in the Las Vegas Valley to generate plant material for experiments at Lake Mead and on BLM land. This project was partly coordinated by, and had substantial involvement, from NPS ATR Ms. Newton. An internet publication on transplant survival of globe mallow was published on the Native Plant Network