Echinocereus viridiflorus var viridiflorus mortality in shortgrass plains of texas: Observations following wildfire and drought

A wildfire of unknown origin ignited in October 2005 at Buffalo Lake National Wildlife Refuge in Randall County, Texas, burning approximately 300 ha of shortgrass plains typified by blue grama (Bouteloua gracilis) and buffalograss (Buchloe dactyloides). Above-average rainfall in the year preceding the fire resulted in abundant herbaceous vegetation and, therefore, fine fuel production. Precipitation following the fire was below normal. We compared density, condition (dead or alive), basal diameters, and heights of Echinocereus viridiflorus var viridiflorus (nylon hedgehog cactus) in a population that was burned by the wildfire and a population in a nearby non-burned area. By May 2006, total density of cacti was similar in the burned and non-burned areas. However, percent mortality was significantly higher, and living plants were both shorter and narrower, in the burned population. Although mortality was high (91%), the wildfire did not kill all of the burned population. It is possible that more cacti would have survived with normal rainfall in the months following the wildfire.