Vegetation - Suisun Marsh - 2018 [ds2963]

This is part of an ongoing monitoring project that the Biogeographic Data Branch (BDB) of the California Department of Fish and Wildlife (CDFW), in collaboration with the Department of Water Resources (DWR) and the CDFW Bay Delta Region (BDR), started in 1999 to track changes in the Suisun Marsh vegetation over time. This is the seventh update using the current mapping standards since the original map was made in 1999. Previous vegetation maps can be viewed and downloaded using the online CDFW Biogeographic Information and Observation System (BIOS) and the links to the associated reports included in the metadata. The reports can also be downloaded from the CDFW website (http://www.dfg.ca.gov/biogeodata/vegcamp/veg_classification_reports_maps.asp). The report associated with this map is available for download at: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=218048.

The mapped project area in 2018 was 91,486 acres. The Suisun Bay made up 24.2% of this area, tidal sloughs made up 3.6%, and areas mapped as vegetation or land use (such as roads or development) made up 72.2%. Of the vegetation and land use area, 15.9% was tidally influenced and the rest was leveed. The current map consists of 39,566 polygons, while the 2015 map had 29,034 polygons. Part of this increase can be attributed to new non-native species occurrences, which do not have a minimum mapping unit. Better imagery and additional field data may have also contributed to the increase in polygons. The total mapped acreage of vegetation changes slightly with each map update due to the tide level at the time the imagery was acquired and channel erosion or accretion since the area was last mapped.