Mercury in soil, vegetation, and organisms across Niwot Ridge, Saddle Catchment, and Green Lakes Valley, 2020 - 2023.

This dataset includes soil, vegetation, water, atmospheric deposition, litterfall, incubation, and organism data from the Niwot Ridge, Saddle Catchment, and Green Lakes Valley collected during 2020 and 2021 to investigate the storage, transformation, and mobilization of mercury in the Colorado Rocky Mountains. During Summer 2020, we collected soil cores (10cm x 3cm) across vegetation plant functional groups in wet meadows, moist meadows, dry meadows, krummholz, subalpine forest, shrub areas, as well as at the inlet and outlet of the Green Lakes in Green Lakes Valley. At each of these sites, we collected leaves from forbs, graminoids, and shrubs, as well as litter (and moss if present). For organisms, we sampled pika hairs from nine different pika trapped on the West Knoll, in addition to caddisfly pupae found in wet meadows in the Saddle Catchment. We analyzed hairs from weasel specimens at the CU Boulder Natural History Museum that were trapped either on, or near, Niwot Ridge. Finally, we analyzed dust samples collected by Dr. Ruth Heindel in 2018 and 2019 on Niwot Ridge. We analyzed soil samples for organic matter; pH; water content; percent carbon, nitrogen, and sulfur; stable carbon, nitrogen, and sulfur isotopes; total mercury; and methylmercury. We analyzed vegetation samples for percent carbon, nitrogen, and sulfur; stable carbon, nitrogen, and sulfur isotopes; total mercury; and methylmercury. We analyzed organism and dust samples for total mercury and methylmercury. During Spring 2021, we collected composite snow cores from 4 sites in the Saddle region and 3 sites in the subalpine forest. We measured snow depth and density to calculate snow water equivalent and then analyzed these samples for sulfate, nitrate, chloride, dissolved organic carbon, dissolved organic nitrogen, total mercury, and methylmercury concentrations. During Summer 2021, we collected soil cores (10cm x 3cm) every other week from June through September from a solifluction lobe, alpine wet