Snow insulates the soil from air temperature, decreasing winter cold stress and altering energy use for organisms that overwinter in the soil. As climate change alters snowpack and air temperatures, it is critical to account for the role of snow in modulating vulnerability to winter climate change. Along elevational gradients in snowy mountains, snow cover increases but air temperature decreases, and it is unknown how these opposing gradients impact performance and fitness of organisms overwintering in the soil. We developed experimentally validated ecophysiological models of cold and energy stress over the past decade for the montane leaf beetle Chrysomela aeneicollis, along five replicated elevational transects in the Sierra Nevada mountains in California. Cold stress peaks at mid-elevations, while high elevations are buffered by persistent snow cover, even in dry years. While protective against cold, snow increases energy stress for overwintering beetles, particularly at low elevations, potentially leading to mortality or energetic trade-offs. Declining snowpack will predominantly impact mid-elevation populations by increasing cold exposure, while high elevation habitats may provide refugia as drier winters become more common.

Climate Data This is the full data set that includes all temperature measures used in cold exposure pricipal component analysis and energy use model output for each winter at each site included in study. The second tab includes metadata for each column. Physiology Data This is the data for all beetles used in the field snow manipulation experiment and all biochemichal assays performed. It includes total protein, glycerol, sorbitol, glucose, and triacylglycerides. Respirometry This is the data set containing all respirometry data used in making the energy use model.