With funding from the US Marine Corps, Jim Malusa and Andrew Sanders created a fine-scale vegetation map of the Chocolate Mountain Aerial Gunnery Range. Jim Malusa and Andrew Sanders conducted field surveys (transects\rapid assessments)for this project, accuracy assessments (AA) were performed by Joe Black from the National Park Service.

The mapping study area, consists of approximately 458,000 acres, of Riverside and Imperial counties. Work was performed on the project between 2015 and 2021. The primary purpose of the project was to allow effective management of the vegetation communities on the CMAGR and provide a baseline for ecosystem management. The vegetation survey and flora are part the Integrated Natural Resources Management Plan (INRMP) prepared by MCAS Yuma under the Sikes Act Improvement Amendments of 1997.

All mapped vegetation units (vegetation types) were named following the conventions of the National Vegetation Classification (NVC) and the Manual of California Vegetation (MCV). So far as possible, they are based on existing classifications created by the DRECP (Reyes et. al., 2020; Menke et al, 2013), the Vegetation Survey and Classification for the Northern and Eastern Colorado Desert Coordinated Management Plan (NECO) (Evens and Hartman, 2007), the Dos Palmas Conservation Area 2013 and 2018 Vegetation Map Report (Sweet et. al., 2019), the Mecca Hills and Orocopia Mountains Vegetation Map Report (Sweet et. al., 2015), and the Vegetation Association Descriptions for Lake Mead National Recreation Area, Death Valley National Park, Mojave National Preserve, and Castle Mountains National Monument (Evens et. al., 2020).

The vegetation map was digitized by Jim Malusa using 2015 color imagery produced for the Marine Corp by Valley Air as the base with Google earth imagery to assist with visual analysis. Map polygons are assessed for Vegetation Type, Percent Cover, Exotics, Development Disturbance, and other attributes. The minimum mapping unit (MMU) is 2.5 acres. Because watercourses are important avenues of animal movements, the watercourse MMU was reduced to 0.1 hectare (0.25 acres).

Field reconnaissance and accuracy assessment enhanced map quality. There was a total of 34 mapping classes. The overall Fuzzy Accuracy Assessment rating for the final vegetation map,at the Alliance and Group levels, is 79.5 percent. More information can be found in the project report, which is bundled with the vegetation map published for BIOs here: https://filelib.wildlife.ca.gov/Public/BDB/GIS/BIOS/Public_Datasets/3100_3199/ds3124.zip