Individual plant growth and reproduction in the black sand extended growing season experiment for East Knoll, Audubon, Lefty, and Trough sites, 2018 - 2020.

As a result of climate change, the Rocky Mountain Front Range is experiencing warmer summers and earlier snowmelt. Due to the importance of snow for regulating soil temperature, growing season length, and available moisture in alpine ecosystems, even small shifts in the snow-free period could have large impacts. The focus of the Black Sand Extended Growing Season Length Experiment is to examine how terrain-related differences in climate exposure influence the way alpine habitats respond to climate change via earlier snowmelt. To simulate how climate exposure may affect plant communities, NWT LTER researchers established 5 experimental sites, each containing a pair 10 x 40m rectangular plots. These sites include north and south facing aspects, subalpine and alpine tundra meadows and a range of hydrological conditions (e.g. dry meadows, moist meadows, wet meadows). We accelerated snowmelt in one plot at each site by adding chemically inert black sand, while keeping the second plot as an unmanipulated control; black sand was added to control plots after snow had naturally melted. We used open top warming chambers (OTCs) to increase summer temperature in three subplots within each of the 10 x 40 m plots. This dataset includes measurements of growth and reproduction for Geum plants as well as counts of buds and flowers were counted and recorded for each tagged study plant, within all snow and warming treatments at all sites except Soddie.

受气候变化影响，落基山脉前缘（Rocky Mountain Front Range）正经历夏季升温与积雪消融提前的现象。由于积雪在高寒生态系统中对调控土壤温度、生长季长度与有效水分至关重要，即便无雪期出现微小变化，也可能产生显著影响。本研究依托黑沙延长生长季实验（Black Sand Extended Growing Season Length Experiment），旨在探究气候暴露度的地形差异如何通过积雪提前消融，影响高寒生境对气候变化的响应模式。为模拟气候暴露度对植物群落的影响，NWT LTER研究人员设立了5个实验样地，每个样地包含一对10×40米的矩形样方。这些样地涵盖南北坡向生境、亚高山与高寒苔草草甸，以及一系列水文梯度条件（例如旱生草甸、中生草甸、湿生草甸）。我们通过施加化学惰性黑沙，加速每个样地中一处样方的积雪消融；另一处样方作为未施加人工干预的对照样方，待积雪自然消融后，需向所有对照样方施加黑沙。我们在每个10×40米样方内设置3个亚样方，并使用开顶式增温箱（open top warming chambers, OTCs）提升夏季气温。本数据集涵盖所有样地（除Soddie样地外）中，各积雪消融与增温处理下，每株标记研究个体的水杨梅（Geum）属植物生长与繁殖状况测量数据，以及每株标记植株的芽与花的计数记录。