Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
Biol Lett. 2021 May;17(5):20210004. doi: 10.1098/rsbl.2021.0004. Epub 2021 May 12.
Recent experiments support the idea that upper thermal limits of aquatic insects arise, at least in part, from a lack of sufficient oxygen: rising temperatures typically stimulate metabolic demand for oxygen more than they increase rates of oxygen supply from the environment. Consequently, factors influencing oxygen supply, like water flow, should also affect thermal and hypoxia tolerance. We tested this hypothesis by measuring the effects of experimentally manipulated flows on the heat and hypoxia tolerance of aquatic nymphs of the giant salmonfly (Plecoptera: ), a common stonefly in western North America. As predicted, stoneflies in flowing water (10 cm s) tolerated water that was approximately 4°C warmer and that contained approximately 15% less oxygen than did those in standing water. Our results imply that the impacts of climate change on streamflow, such as changes in patterns of precipitation and decreased snowpack, will magnify the threats to aquatic insects from warmer water temperatures and lower oxygen levels.
最近的实验支持了这样一种观点，即水生昆虫的上限热极限至少部分是由于缺乏足够的氧气造成的：温度升高通常会比环境中氧气供应的增加更刺激对氧气的代谢需求。因此，影响氧气供应的因素，如水流，也应该影响热耐受和缺氧耐受。我们通过测量实验中对水流的控制对水生稚虫（Plecoptera：）的热和缺氧耐受的影响来验证这一假设，稚虫是北美西部常见的石蝇。正如预测的那样，在流动的水中（10 厘米/秒）的石蝇能够耐受比静止水中温度高约 4°C、氧气含量低约 15%的水。我们的结果表明，气候变化对径流量的影响，如降水模式的变化和积雪减少，将加剧对水生昆虫的威胁，使其面临更高的水温和更低的氧气水平。
