Year: 2025
Type: article
Abstract: Ice thaw and enhanced bedrock weathering are increasing sulfate export in alpine streams, which may change sulfur (S) and other biogeochemical cycles in adjacent wetlands. We compared S and carbon (C) concentrations and sulfate reduction rates (SRRs) across three wetland types in the Colorado Rocky Mountains, USA: snowmelt‐fed wetlands (SFWs), periglacial solifluction lobes (PSLs), and subalpine wetlands (SAWs). We found that each wetland type had unique biogeochemical characteristics. Subalpine wetlands had the highest soil C (37.2 ± 8.7%C) and SRRs (29.3 ± 21 nmol mL−1 soil day −1) compared with SFWs and PSLs, which had lower %C and moderate to low SRRs, respectively. Subalpine wetlands accumulated little sulfate, whereas PSLs had high concentrations (0.04 ± 0.04 vs. 0.6 ± 1.4 mg S g−1 dry soil respectively); SFWs had low sulfate concentrations (0.02 ± 0.01 mg S g−1 dry soil). Sulfate‐S stable isotope data suggest different sources of S in the SFWs and PSLs: atmospheric and geologic, respectively. The data indicate that high C supports high SRRs in SAWs, whereas SRRs may be C‐limited and co‐limited by C and S in PSLs and SFWs, respectively. With climate warming, SAWs have the greatest potential to release more C to the atmosphere, SFWs will likely decrease in size and experience changes in plant community composition, and PSLs may be sources of acid rock drainage. These data demonstrate different biogeochemical fates of S and C in three wetland types present across alpine landscapes, and notable consequences for biogeochemical cycling as warming continues.
DOI: 10.1029/2024jg008616
Authors: Laura T. Rea, Molly E. Huber, Hannah R. Miller, Clifford Adamchak, Eve‐Lyn S. Hinckley
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
Awards: CAREER: Acid Rain to Agriculture: An Integrated Research and Education Platform to Understand Human Manipulation of the Sulfur Cycle, LTER: Long-term research on the dynamics of high-elevation ecosystems -- a framework for understanding ecological responsiveness to climate change, G6671297155
OpenAlex ID: W4409327787