Using a habitat suitability model to promote exploratory surveys of an endangered plant on California’s Channel Islands

Santa Cruz Island rockcress (Sibara filifolia) is an endangered annual wildflower in the mustard family that is endemic to California’s Channel Islands. The plant was believed to be extinct since the 1930s until it was rediscovered on San Clemente Island in 1986 and later found on Santa Catalina Island in 2001. However, Santa Cruz Island rockcress has not been documented on Santa Cruz Island in nearly 100 years. Over the last three years, Santa Barbara Botanic Garden has led a survey-based project, in coordination with the Sibara filifolia Working Group, to survey and monitor known Santa Cruz Island rockcress locations on Santa Catalina Island and also explore potentially suitable habitat as defined by a habitat suitability model. Concurrently, expanded surveys are being conducted on San Clemente Island and searches for the extirpated populations on Santa Cruz Island are ongoing. This presentation will include results of the model-based surveys and population monitoring thus far, implications of our findings, and future plans to advance Santa Cruz Island rockcress conservation and recovery.