Location: Exotic and Invasive Weeds Research
Project Number: 2030-22000-026-11
Start Date: Jan 01, 2011
End Date: May 31, 2015
We will obtain geospatial data with GPS units to determine the distribution and occupied area of perennial pepperweed in tidal marshlands of Southampton Bay Natural Preserve, Benicia State Recreation Area, San Francisco Estuary. Cover classes of weed-occupied patches will be record along with data on habitat conditions to tract marshwide efficacy of herbicide applications. We will establish stratified random control and treatment plots, and will measure changes in live L. latifolium stem density, biomass and plant community succession to evaluate efficacy of alternative management actions in endangered species protection zones, and the potential need for adaptive change in approach. In 24 randomized 10m x 4m plots stratified by marsh zone and microhabitat type, we will evaluate pre-treatment influence of pepperweed on the marsh community with MANOVA analysis. We will measure the abundance of all native and exotic plant species in each plot following weed treatment actions, and we will use ANVOCA for repeated measures analysis to evaluate recovery of the plant community following weed management actions. If warranted, we will design and conduct pilot tests of augmentative restoration approaches, potentially evaluating thatch removal and experimental plantings of native plants to improve restoration success. Results will be directly applicable to weed control strategies, conservation management, ecological restoration and endangered plant recovery.