Conservation of succulents in desert grasslands managed by fire

Abstract

Many species of succulents, including cacti, live in desert grasslands which are being increasingly managed by fire. Plants may survive by (1) being missed by fire in refugia or (2) tolerating fire by vegetative recovery. Glasshouse experiments showed that all growth forms tested were physically capable of post-fire growth given optimal conditions. In a field survey in Arizona the mortality of 14 species of cacti and three leaf succulents was normally <25% within 14 months after burning. Of surviving plants, 87% tolerated burning and 13% were unburned (primarily in areas accidentally missed by the fire), accounting for 57 and 9% of the pre-fire succulent communities, respectively. Fewer plants survived more intense or repeated fires. Since the majority of plants alive after a fire had survived being burned it is evident that long-term conservation of succulents is dependent on the fire regime imposed.