This study presents a comprehensive vegetation mapping inventory project undertaken in Mojave National Preserve (MOJA) and Castle Mountains National Monument (CAMO), two areas within the National Park Service’s Mojave Desert Network (MOJN). Covering a combined area of over 1.6 million acres along the California-Nevada border, these sites encompass diverse desert ecosystems, including valleys, washes, sand dunes, volcanic formations, and Joshua tree forests. The project, initiated in 2010 by the National Park Service’s Vegetation Mapping Inventory (VMI), aimed to document and classify the plant communities in these areas.

The project unfolded over six phases between 2011 and 2021, starting with a review of existing vegetation data and the development of a comprehensive work plan. In collaboration with the California Native Plant Society (CNPS) and the University of Nevada, Las Vegas (UNLV), field data were collected from 630 plots and observation points, supplemented by 588 samples from previous studies. The data were used to classify 67 plant alliances and two landform types, ultimately identifying 136 plant associations within MOJA and CAMO.

The vegetation map for the project, covering the entire 1.6-million-acre area, was created using a hybrid mapping approach that combined manual and automated techniques. The map was based on 2018 National Agriculture Imagery Program (NAIP) basemap data and was validated through ground-based verification efforts. The accuracy of the final vegetation map was assessed at 91%, with a Kappa value of 92%, indicating a high level of reliability. The minimum mapping unit is 1.2 acres (0.5 hectares).

The final products of this project include a spatial geodatabase, digital field photos, metadata, a classification report, and a field key to the vegetation alliances. These resources provide a valuable tool for ongoing research and conservation efforts in these ecologically significant areas.

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/ds3128.zip