Department of Integrative Biology, University of California, Berkeley, California, USA.
Department of Biology, Sonoma State University, Rohnert Park, California, USA.
Glob Chang Biol. 2021 Dec;27(23):6103-6116. doi: 10.1111/gcb.15912. Epub 2021 Oct 11.
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 tradeoffs. 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.
雪使土壤与空气温度隔离，减少冬季寒冷压力，并改变在土壤中越冬的生物的能量利用。随着气候变化改变积雪和空气温度，必须考虑到雪在调节对冬季气候变化脆弱性方面的作用。在多雪山区的海拔梯度上，雪盖增加，但空气温度下降，目前尚不清楚这些相反的梯度如何影响在土壤中越冬的生物的性能和适应性。在过去十年中，我们为加利福尼亚州内华达山脉的五个重复海拔梯度的山地叶甲 Chrysomela aeneicollis 开发了经过实验验证的冷应激和能量应激生态生理学模型。在海拔较高的地区，由于持续的积雪覆盖，即使在干旱年份，冷应激也会达到峰值。虽然雪对越冬甲虫有防寒作用，但它会增加能量应激，特别是在低海拔地区，这可能导致死亡或能量权衡。随着干燥冬季变得更加普遍，积雪减少将主要通过增加寒冷暴露来影响中海拔地区的种群，而高海拔生境可能提供避难所。
