Special soils with extreme properties form insular habitats often supporting endemic species and unique communities. An uncertainty is how these communities may change through time, such as during periods of climatic changes including droughts. On unique, gypsum-associated soils in the Mojave Desert, USA, we examined multi-decade change in plant communities, including conservation-priority, special-status species. Within our 18-year study period, different community features and components varied in their degree of stability or change among three measurement years (2008, 2020 and 2025). Community species composition, total plant cover, cover of gypsophiles associated with gypsum, and shrub density changed little, while turnover in most perennial forbs was high. Two conservation-priority perennial forbs, Anulocaulis leiosolenus and Arctomecon californica, declined in density by 86–100% between 2008 and 2025, though the species may persist in soil seed banks and have naturally cyclic population fluctuations. Despite our study encompassing an overall multi-decade dry period and a severe 2020–2022 drought, turnover in shrubs was minimal. Although dieback occurred, multiple metrics (e.g., species rank-abundance curves) of perennial community structure were stable. Results portray these gypsum-associated communities as exhibiting high temporal turnover in perennial forbs overall, concomitant with stable shrub components and community structure.