Spatial and temporal variation in thermal conditions are important dimensions of aquatic landscapes, yet we do not understand how this heterogeneity will respond to climate change. Snowpack in many regions is declining but impacts on aquatic thermal regimes remain poorly understood. Our analyses of summer stream temperatures across a complex river basin in southwest Alaska show that loss of snowpack has disproportionate effects on water temperatures in streams that are cold under typical conditions, thereby homogenizing stream temperatures across the landscape during low snow conditions. Streams draining steep watersheds warmed from a summer average of 4–8°C between high and low snow years and became more responsive to variation in regional air temperature (as proxy for solar radiation), while streams draining flat watersheds changed negligibly. Our results suggest that conservation strategies for aquatic landscapes that focus on snow‐dominated cold‐water refugia may not be robust to future climate warming and changes in snowpack.

中文翻译：

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低积雪减少了景观中溪流之间的热响应多样性

热条件的时空变化是水生景观的重要方面，但我们不了解这种异质性将如何应对气候变化。许多地区的积雪正在减少，但对水热状况的影响知之甚少。我们对阿拉斯加西南部复杂河流域的夏季溪流温度的分析表明，积雪的损失对典型条件下寒冷的溪流中的水温有不成比例的影响，从而在低雪情况下使整个景观中的溪流温度均匀化。从陡峭的集水区排水的河流从高雪年和低雪年之间的夏季平均4-8°C开始变暖，并且对区域气温的变化更加敏感（作为太阳辐射的替代物），而从平坦的集水区排水的河流的变化可以忽略不计。