The magnitude and frequency of soil frost events might increase in northern temperate regions in response to climate warming due to reduced insulation caused by declining snow cover. In temperate deciduous forests, increased soil frost severity can hamper tree growth and increase the mortality of fine roots, soil fauna and microorganisms, thus altering carbon and nutrient cycling. From single-site studies, however, it is unclear how the sensitivities of these responses change along continental gradients from regions with low to high snowfall. We conducted a gradient design snow cover and soil temperature manipulation experiment across a range of lowland beech forest sites to assess the site-specific sensitivity of tree growth and biogeochemical cycling to soil cooling. Even mild and inconsistent soil frost affected tree increment, germination, litter decomposition and the retention of added ¹⁵N. However, the sensitivity of response (treatment effect size per degree of warming or cooling) was not related to prevailing winter climate and snow cover conditions. Our results support that it may be valid to scale these responses to simulated winter climate change up from local studies to regional scales. This upscaling, however, needs to account for the fact that cold regions with historically high snowfall may experience increasingly harsh soil frost conditions, whereas in warmer regions with historically low snowfall, soil frost may diminish. Thus, despite the uniform biotic sensitivity of response, there may be opposing directions of winter climate change effects on temperate forests along continental temperature gradients due to different trends of winter soil temperature.

由于气候变暖，由于积雪减少导致隔热层减少，北部温带地区土壤霜冻事件的数量和频率可能会增加。在温带的落叶林中，增加的土壤霜冻严重性会阻碍树木的生长并增加细根，土壤动植物和微生物的死亡率，从而改变碳和养分循环。然而，从单点研究来看，尚不清楚这些响应的敏感性如何随降雪量从高到低的区域的大陆梯度变化。我们在一系列低地山毛榉林地进行了渐变设计的积雪和土壤温度控制实验，以评估树生长和生物地球化学循环对土壤冷却的特定场所敏感性。即使是轻度和不一致的土壤霜冻也会影响树木的生长，发芽，^15N。但是，响应的敏感性（每增温或降温的治疗效果大小）与盛行的冬季气候和积雪条件无关。我们的结果支持将对模拟冬季气候变化的这些响应从本地研究扩展到区域规模可能是有效的。但是，这种升级需要考虑以下事实：具有历史高降雪量的寒冷地区可能会遇到日益严峻的土壤霜冻条件，而在具有历史低降雪量的较温暖地区，土壤霜冻可能会减少。因此，尽管生物对反应具有统一的敏感性，但由于冬季土壤温度的不同趋势，冬季气候变化对沿大陆温度梯度的温带森林的影响可能存在相反的方向。