Comparative Foliar Water Uptake and Leaf Hydrophobicity among Eight Species of California Ferns

In 2014, Southern California experienced the worst drought in the last 1,200 years. Recent tree ring analysis and climate models suggest that this event may be the front end of a “mega-drought” in the southwestern United Sates. Ferns might be particularly vulnerable. In a region where drought is severe, ecological surveys provide insight into the adaptations of organisms living on the edge of survival. In this study, the mechanisms of drought tolerance for eight species of ferns in the Santa Monica Mountains are assessed with a focus on foliar water uptake and resurrection strategies. We find that species are significantly different (P \u3c 0.001) in their ability to absorb water through leaves and correlate this to minimum seasonal water potential and hydrophobicity of leaf surface. Secondly, we irrigate Pentagramma triangularis in the field and track chloroplast recovery. We find possible evidence of embolism reversal. Taken together, this study explores the methods of survival of the most ancient family of vascular plants