Climate and Ecology Unit, Research and Museum Collection Office, MUSE-Museo delle Scienze, Corso del Lavoro e della Scienza 3, Trento, 38122, Italy.
Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Scientific Campus, Via Torino, 155, Mestre-Venice 30172, Italy.
Sci Total Environ. 2022 Sep 1;837:155759. doi: 10.1016/j.scitotenv.2022.155759. Epub 2022 May 6.
We evaluated the effect of global warming on invertebrate communities at high altitudes using data from the Careser system. We procured data on air temperature, which was obtained over 50 years at altitudes above 2600 m a.s.l., and data on water temperature, which was available for approximately 30 years. We sampled thrice in the past 20 years (2001, 2014, 2018) at three sampling sites (CR0-metakryal, CR1-hypokryal, CR2-glacio-rhithral) of the Careser glacier-fed stream and its main non-glacial tributary (CR1bis-krenal). Warmer climates were observed in the last decade compared to the 1980s, with a mean maximum summer air temperature (mTmax) increase of 1.7 °C at 2642 m a.s.l. and 1.8 °C at 2858 m a.s.l. Compared to air temperatures, the rise in water temperature was delayed by approximately 20 years; water mTmax started to increase in 2003, reaching 8.1 °C at 2642 m a.s.l. and 2.4 °C at 2858 m a.s.l in the year 2020. The invertebrate community exhibited a delayed response approximately 13 years from the water warming; there was a sequential increase in the number of taxa, Shannon diversity, and after 17 years, functional diversity. In the kryal sites, taxonomical and functional diversity changed more consistently than in the glacio-rhithral site in the same period, due to the arrival of taxa that were previously absent upstream and bearers of entirely new traits. Progressive taxonomical homogenisation was evident with decreasing glacial influence, mainly between glacio-rhithral and krenal sites. The numbers of Diamesa steinboecki, an insect that was adapted to the cold, declined in summer (water mTmax >6 °C and air mTmax >12 °C). This study highlights the mode and time of response of stream invertebrate communities to global warming in alpine streams and provides guidelines for analysing changes in the stream invertebrate communities of other glacial systems in alpine regions.
我们利用 Careser 系统的数据评估了全球变暖对高海拔无脊椎动物群落的影响。我们获取了过去 50 年海拔 2600 米以上地区的空气温度数据，以及过去 30 年的水温数据。我们在过去 20 年（2001 年、2014 年、2018 年）的三个采样点（CR0-metakryal、CR1-hypokryal、CR2-glacio-rhithral）对 Careser 冰川溪流及其主要非冰川支流（CR1bis-krenal）进行了三次采样。与 20 世纪 80 年代相比，过去十年的气候变暖，海拔 2642 米处夏季空气最高温度（mTmax）的平均增长率为 1.7°C，海拔 2858 米处的增长率为 1.8°C。与空气温度相比，水温的上升滞后了大约 20 年；水温 mTmax 于 2003 年开始上升，到 2020 年，海拔 2642 米处达到 8.1°C，海拔 2858 米处达到 2.4°C。无脊椎动物群落的反应滞后了大约 13 年，从水温变暖开始；在 17 年之后，分类和功能多样性相继增加。在 kryal 站点，由于以前不存在于上游的分类单元的到来以及具有全新特征的载体，分类学和功能多样性的变化比同一时期的 glacio-rhithral 站点更一致。随着冰川影响的减小，主要是在 glacio-rhithral 和 krenal 站点之间，逐渐出现分类学同质化。适应寒冷的昆虫 Diamesa steinboecki 的数量在夏季减少（水温 mTmax >6°C，空气 mTmax >12°C）。本研究强调了高山溪流中无脊椎动物群落对全球变暖的反应模式和时间，并为分析高山地区其他冰川系统溪流无脊椎动物群落的变化提供了指导。
