Invasive plant species early detection in the San Francisco Bay Area Network: 2016 annual report

Wrubel, Eric

This report summarizes the results of the 2016 invasive plant early detection protocol surveys for the San Francisco Bay Area Network (SFAN) Inventory and Monitoring Program (I&M). Invasive plants (see Glossary) represent a high priority vital sign for SFAN because of the negative effects they have on park resources, including altering ecosystem processes (fire regime, hydrology, soil biogeochemical cycling, etc.), reducing habitat quality and scenic value, and increasing trail maintenance needs. The 2016 early detection surveys were conducted in Golden Gate National Recreation Area (GOGA), John Muir National Historic Site (JOMU), Pinnacles National Monument (PINN), and Point Reyes National Seashore (PORE). Objectives and methods for the 2016 field season were based on a peer-reviewed early detection protocol published in the NPS Natural Resource Report series (Williams et al. 2009). Including field seasons when pilot data were collected, 2016 was the eighth field season of data collection in PINN and JOMU, the ninth in PORE, and the tenth in GOGA. Volunteers played an important role in the implementation of the 2016 field surveys. At GOGA, 7 volunteers assisted staff to conduct surveys, contributing 237 hours. At PORE, 4 volunteers contributed 221 hours. At PINN, 2 volunteers contributed 52 hours performing surveys. At JOMU, 3 volunteers contributed 17 hours performing surveys.Seventy miles of trails and roadsides were surveyed within GOGA and 651 individual occurrences of target weed species were recorded. Sixty-eight miles of trails and roadsides were surveyed at PORE and 689 occurrences of target weeds were recorded. Sixteen miles of trails and roadsides were surveyed at PINN and a total of 19 priority species were detected in the 275 belt transects surveyed. Six miles of trails were surveyed at JOMU, and 68 priority weed occurrences were recorded. In 2016, six plant species were discovered during early detection surveys that were new records for the SFAN parks. Three of these new species were found at GOGA, two were found at PINN, and one was found at PORE. Four of these species were added to the 2017 park priority lists due to their potential invasiveness. Maps were created for all priority plant populations recorded at GOGA, PORE, PINN, and JOMU. Outreach was conducted through monthly newsletters and the iNaturalist Marin County Early Detection Project. Collaborative efforts with park staff, partners, and external agencies continued to facilitate communication of findings and to broaden the early detection network.

Invasive plant species early detection in the San Francisco Bay Area Network: 2016 annual report

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