Hydraulic trait diversity explains differential sensitivity of grassland communities to extreme drought

Climate change is expected to cause droughts reminiscent of the dust bowl. Extreme droughts such as these have differential impacts on grassland communities around the world, with some more sensitive than others; however, a mechanistic understanding of this variable sensitivity is lacking. We measured leaf hydraulic traits indicative of drought tolerance across six central US grasslands following an extreme natural drought. We expected the least sensitive grasslands to be dominated by the most drought tolerant species; however, our results indicate that hydraulic trait diversity may be more important than mean trait values for explaining differential drought sensitivity of grasslands.