ABSTRACT A scarce natural snow cover forces an increasing use of artificial snow on ski slopes and returns a small amount of snowmelt water available to plants outside the pistes at the beginning of the growing season. We tested if the use of artificial snow on the ski slopes and the decreased natural snow cover outside the ski slopes lead to changes in the leaf ecophysiology of dominant species in a ski area located in Northern Italy. Using carbon (13C/12C) and oxygen (18O/16O) stable isotope ratios in plant leaves, we estimated the intrinsic water use efficiency (iWUE) and we speculated about changes in photosynthesis and stomatal conductance. Furthermore, carbon and nitrogen concentration, pigments and dry matter content, and the specific area of leaves were measured. We found a higher iWUE of the plants on the ski slopes than outside, probably because the plants on the ski piste are exposed to a condition close to waterlogging that can lead them to regulate their stomata differently than the plants outside the pistes. This behaviour was observed particularly in Ranunculus acris and in Tussilago farfara, for these species the water surplus on the piste may have affected the plants’ gas exchanges.

中文翻译：

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通过同位素组成评估山地草原群落对滑雪坡管理的生态生理反应

摘要 稀缺的天然积雪迫使越来越多的人造雪在滑雪场上使用，并在生长季节开始时向滑雪道外的植物返回少量可用的融雪水。我们测试了在滑雪坡上使用人造雪和滑雪坡外自然积雪的减少是否会导致意大利北部滑雪区优势物种的叶子生态生理发生变化。使用植物叶片中的碳 (13C/12C) 和氧 (18O/16O) 稳定同位素比率，我们估计了内在水分利用效率 (iWUE)，并推测了光合作用和气孔导度的变化。此外，还测量了碳和氮浓度、色素和干物质含量以及叶子的比表面积。我们发现滑雪坡上植物的 iWUE 比外面高，可能是因为滑雪道上的植物暴露在接近积水的条件下，这会导致它们调节气孔的方式与滑雪道外的植物不同。这种行为特别在毛茛属（Ranunculus acris）和杜西拉戈法拉（Tussilago farfara）中观察到，对于这些物种，滑雪道上的水过剩可能影响了植物的气体交换。