Location: Exotic and Invasive Weeds Research
Project Number: 2030-22000-028-02-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Jan 1, 2011
End Date: Dec 31, 2015
1)Assess the population size and marsh-wide distribution and abundance of persistent Lepidium latifolium infestations following annual weed management control actions (herbicide applications) initiated in 2010. 2) Assess the efficacy of alternative weed control measures in areas where herbicide treatment are prohibited for protection of threatened populations of black rails. 3)Assess native community response to L. latifolium reduction, including the impact of post-herbicide applications on native plant abundance. If warranted, design and conduct pilot scale experiments to test augmentative restoration approaches for native plant community recovery and prevention of secondary weed invasion following weed management actions.
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.