Sulfate reductions rates in alpine wetlands, 2021.

Alpine ecosystems serve as crucial water resources for many areas of the world, and biogeochemical cycling in these regions can influence the chemistry of water flowing into downslope watersheds. Alpine and subalpine wetlands are understudied systems of particular interest since lowland wetlands are known to have high rates of biogeochemical activity that can disproportionally affect carbon (C) and nutrient uptake, sequestration, and transformations within the landscape. Wetland processes play a central role in sulfur (S) transformations and have conditions that can support sulfate reduction. Sulfate reduction determines the sequestration of S in wetlands and interacts closely with a multitude of other element cycles, including iron, carbon, nitrogen, and mercury. As alpine systems warm due to climate change, it is important to characterize the biogeochemical processes at these sites to predict how they may shift in response. Sulfate reduction rates were measured in three wetlands at the Niwot Ridge Long Term Ecological Research site. A new radioactive tracer method was adapted and streamlined to suit alpine soils. This work trials and assesses various methodological approaches, as well as documents sulfate reduction rates from these sites, the first time this process has been measured at Niwot Ridge. Reduction rates at one site were measured three times, to track changes across the Summer 2021 field season.