Patterns in stream greenhouse gas dynamics from mountains to plains in northcentral Wyoming
| Autor: | Henry B. Glick, C. Kuhn, Lindsi Seegmiller, Peter A. Raymond, C. Bettigole, Chadwick Dearing Oliver |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Hydrology Atmospheric Science geography geography.geographical_feature_category Baseflow Watershed 010504 meteorology & atmospheric sciences Ecology 010604 marine biology & hydrobiology Drainage basin Paleontology Soil Science Forestry STREAMS Aquatic Science 01 natural sciences Carbon cycle Ecoregion Greenhouse gas Snowmelt Environmental science 0105 earth and related environmental sciences Water Science and Technology |
| Zdroj: | Journal of Geophysical Research: Biogeosciences. 122:2173-2190 |
| ISSN: | 2169-8953 |
| Popis: | Quantification of stream contributions to global carbon cycling is key to understanding how freshwater streams transmit and transform carbon between terrestrial and atmospheric pools. To date, greenhouse gas emissions of carbon dioxide and methane from freshwaters, particularly in mountainous regions, remains poorly characterized due to a lack of direct field observations. Using a unique longitudinal approach, we conducted field surveys across two ecoregions (Middle Rockies and Great Plains) in the Clear Creek watershed, a sub-watershed of Wyoming's Powder River Basin. We took direct measurements of stream gases using headspace sampling at thirty sites (8 June - 23 October). We observed the lowest and most variable concentrations in headwaters, which flow through a federally designated alpine wilderness area. By contrast, the Great Plains exhibited 1.45 and 4 times higher pCO2 and pCH4 concentrations and the relative contributions of methane increased downstream. Fluxes during snowmelt were 45% and 58% higher for CO2 and CH4 than during baseflow but overall were lower than estimates for other systems. Variability for pCO2 was highest during late summer and in the uppermost sections of the headwaters. The high heterogeneity and common undersaturation observed through space and time, especially in the mountains, suggests downscaled regional estimates may fail to capture variability in fluxes observed at these smaller scales. Based on these results, we strongly recommend higher resolution time series studies and increased scrutiny of systems at near equilibrium, inclusive of winter storage and ice-off events, to improve our understanding of the effects of seasonal dynamics on these processes. |
| Databáze: | OpenAIRE |
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