Mediating water temperature increases due to livestock and global change in high elevation meadow streams of the Golden Trout Wilderness

Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two “resting” meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ram...

气候变化引发的气温上升正不断逼近诸多物种的热耐受极限，但目前学界对气候变暖与土地利用等其他人为干扰因素之间的交互作用仍知之甚少。为探明气候变暖与家畜放牧对美国加利福尼亚州金鳟荒野（Golden Trout Wilderness）内三处高海拔草甸溪流水温的联合影响，我们于2008年至2013年间对三处草甸溪流的河岸植被开展了测量，并对其水温进行了监测。其中两处为"休牧"草甸，另一处草甸则处于部分放牧状态。自19世纪以来，这三处草甸均长期遭受牛、羊的放牧活动，其溪流中栖息着濒危物种加利福尼亚金鳟（California golden trout，*Oncorhynchus mykiss aguabonita*）。1991年，研究人员在其中一处草甸（马尔基草甸，Mulkey）中设立了禁牧围栏（livestock exclosure），使得该区域内的一段溪流免受放牧干扰，以尽可能降低牛群带来的负面影响。2001年，另外两处草甸（大惠特尼草甸与拉姆草甸，Big Whitney and Ram...）已完全移除了牛群放牧活动。