Vegetation - Los Penasquitos Lagoon [ds3034]

The San Diego Coast District, Department of Natural Resources, and California State Parks created a fine-scale vegetation map of portions of the Los Penasquitos Lagoon. San Diego Coast District, Department of Natural Resources, and California State Parks conducted field reconnaissance assistance for this project, as well as accuracy assessment (AA) field data collection. CDFW’s Vegetation Classification and Mapping Program (VegCAMP) provided in-kind service to allocate and score the AA. The mapping study area consists of approximately 1204.82 acres of San Diego county. Prior to performing field work, preliminary polygons were delineated on a 2013 true color aerial image with 6 inch pixel resolution. The majority of polygons were later surveyed in the field and redrawn as needed to accurately reflect the boundaries of each vegetation type. Field data was collected from mid 2013 to early 2015. The primary purpose of the project was to further CDFW’s goal of developing fine-scale digital vegetation maps as part of the California Biodiversity Initiative Roadmap of 2018. Mapped vegetation was classified according to the Vegetation Manual for Western San Diego County (AECOM 2011) codes. Holland (sensu Oberbauer 2008) classes were derived via the crosswalk recommended in the Vegetation Manual for Western San Diego County (AECOM 2011). CNPS under separate contract and in collaboration with CDFW VegCAMP developed the floristic vegetation classification used for the project. The floristic classification follows protocols compliant with the Federal Geographic Data Committee (FGDC) and National Vegetation Classification Standards (NVCS). The vegetation map was produced applying heads-up digitizing techniques using LIDAR vegetation elevation data, false color infrared, and other aerial imagery. Map polygons are assessed for Vegetation Type, Percent Cover, Exotics, Development Disturbance, and other attributes. The minimum mapping unit (MMU) is 0.1 hectares. Mappers retained salt panne, mudflat, and water polygons that were below the MMU due to the importance of these habitats. In addition, polygons that were enclosed by these habitat types (such as islands of Salicornia pacifica surrounded by water) were allowed as exceptions to the MMU rule, as were polygons on the perimeter of the mapped area. Polygons initially mapped as salt panne, mudflat, or water that were later changed to a different category based on examination in the field were also allowed as exceptions to the MMU rule. Field reconnaissance and accuracy assessment enhanced map quality. The accuracy assessment was performed in the autumn of 2016. A total of 61 plots from 20 categories were evaluated. The final map accuracy was 56% using a traditional error matrix. There was a total of 42 mapping classes. The overall Fuzzy Accuracy Assessment rating for the final vegetation map, at the association levels, is 89% percent.