Vegetation - Coachella Valley Floor [ds2898]

This unit was mapped using the California Department of Fish and Wildlife (CDFW) and California Natural Plant Society Combined (CNPS) Vegetation Classification and Mapping Program protocol (CNPS 2014). The primary purpose was to develop a dynamic and accurate vegetation map for the Coachella Valley Floor Reserve Management Unit, so that it may be applied to further conservation efforts and assist with management of the 27 species and 27 natural communities listed within the plan.

Map polygons were assessed for vegetation type, percent cover, presence of exotics, anthropogenic disturbance, and roadedness. This map is an updated map for the year 2018 for the area within the 95,000 acres that fall within the 18 CVMSHCP Management Units on the Coachella “Valley Floor.” Within the study areas, rapid assessment protocol vegetation plots, basic vegetation assessment plots and supplemental reconnaissance observations were obtained within the study at pre-determined points in order to document the plant community, disturbances, and invasive species across space and types.

Heads-up photo-interpretation of 2013 local flight true-color imagery and field information were combined to produce delineations of vegetation alliances and associations according to the California Department of Fish and Wildlife classification system, outlined in the Manual of California Vegetation (MCV) Second Edition (Sawyer et al. 2009). Additional field data was collected in 2018 and incorporated into the 2018 map update.

The 2018 map delineation was done by photo-interpretation of updated imagery, with a focus on stand changes, mortality, cover and land use changes, and other anthropogenic changes. To better focus on conservation of particular habitats, there are several alliances where the minimum mapping unit (MMU) is less than an acre; including Prosopis glandulosa Woodland Alliance (MMU .5 acres), and Washingtonia fillifera Shrubland Alliance (MMU .34 acres), as well as wetlands and certain wash types which displayed complexity that would necessitate delineation.

In order to better delineate habitat for the aeolian suite of species covered under the Plan, the following provisional alliances were used: Dicoria canescens--Oenothera deltoides Sparsely Vegetated Active Dune Provisional Alliance; Larrea tridentata / Abronia villosa Stabilized Sand Fields Provisional Alliance; and Psorothamnus arboresens / Dicoria canescens Ephemeral Sand Fields Provisional Alliance .