Biogeochemistry: Stable Isotope Applications Active
Biogeochemical cycling is a cornerstone of ecosystem function and structure. Much has been learned about element cycles in a variety of systems using standard geochemical techniques.
Isotope geochemistry can offer unique and additional insights into sources, processes, and mechanisms. Further, many light stable isotope techniques are amenable to studying element cycling, but logically can be extended to consumer organisms and therefore integrate food webs, offering a more complete assessment of ecosystems. Light isotopes commonly used in this context include hydrogen, carbon, nitrogen, oxygen, and sulfur. Further, such techniques can complement studies of related biogeochemical cycles that have proven challenging to study directly with isotopic techniques.
The Stable Isotope Laboratory maintained by the Crustal Geophysics and Geochemistry (CGG) and Fort Collins (FORT)Science Centers is a state-of-the-art facility with modern instrumentation capable of analyzing the isotopic composition of nearly any conceivable sample matrix. Laboratory staff and PI's have significant expertise in isotope systematics of the geosphere, biosphere, and hydrosphere. The Laboratory has demonstrated innovative approaches to challenging questions and as such, has significant latitude to address emerging issues in ecosystem science. In addition, the Laboratory is highly competent in standard mass spectrometric methods and maintains a library of standard operating procedures. The full resources of the Laboratory are available to this Task and relevant research projects.
The objectives of this project are to: employ isotope techniques in tandem with standard geochemistry to better resolve critical biogeochemical processes; to continue to develop sulfur isotope techniques to refine this element cycle, particularly relationships with non-essential metals such as Hg and to couple biogeochemical cycles to food webs through intensive and interdisciplinary place-based studies.
Below are publications associated with this project.
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production
Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error
Benthic macroinvertebrate and fish communities in Lake Huron are linked to submerged groundwater vents
Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008
- Overview
Biogeochemical cycling is a cornerstone of ecosystem function and structure. Much has been learned about element cycles in a variety of systems using standard geochemical techniques.
Sources/Usage: Some content may have restrictions. View Media DetailsIsotope geochemistry can offer unique and additional insights into sources, processes, and mechanisms. Further, many light stable isotope techniques are amenable to studying element cycling, but logically can be extended to consumer organisms and therefore integrate food webs, offering a more complete assessment of ecosystems. Light isotopes commonly used in this context include hydrogen, carbon, nitrogen, oxygen, and sulfur. Further, such techniques can complement studies of related biogeochemical cycles that have proven challenging to study directly with isotopic techniques.
The Stable Isotope Laboratory maintained by the Crustal Geophysics and Geochemistry (CGG) and Fort Collins (FORT)Science Centers is a state-of-the-art facility with modern instrumentation capable of analyzing the isotopic composition of nearly any conceivable sample matrix. Laboratory staff and PI's have significant expertise in isotope systematics of the geosphere, biosphere, and hydrosphere. The Laboratory has demonstrated innovative approaches to challenging questions and as such, has significant latitude to address emerging issues in ecosystem science. In addition, the Laboratory is highly competent in standard mass spectrometric methods and maintains a library of standard operating procedures. The full resources of the Laboratory are available to this Task and relevant research projects.
The objectives of this project are to: employ isotope techniques in tandem with standard geochemistry to better resolve critical biogeochemical processes; to continue to develop sulfur isotope techniques to refine this element cycle, particularly relationships with non-essential metals such as Hg and to couple biogeochemical cycles to food webs through intensive and interdisciplinary place-based studies.
- Publications
Below are publications associated with this project.
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual, integrated asseAuthorsLisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Mark C. Marvin-DiPasquale, Craig A. Stricker, Wesley A. Heim, Philip A.M. Bachand, Collin A. Eagles-Smith, Gary Gill, Mark Stephenson, Charles N. AlpersHolocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Aeolian dust is rarely considered an important source for nutrients in large peatlands, which generally develop in moist regions far from the major centers of dust production. As a result, past studies assumed that the Everglades provides a classic example of an originally oligotrophic, P-limited wetland that was subsequently degraded by anthropogenic activities. However, a multiproxy sedimentaryAuthorsPaul H. Glaser, Barbara C. S. Hansen, Joseph J. Donovan, Thomas J. Givnish, Craig A. Stricker, John C. VolinMercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production
The role of live vegetation in sediment methylmercury (MeHg) production and associated biogeochemistry was examined in three types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields) and adjacent managed natural wetlands (cattail- and bulrush or tule-dominated) in the Yolo Bypass region of California's Central Valley, USA. During the active growing season for each wAuthorsLisamarie Windham-Myers, Mark Marvin-DiPasquale, Craig A. Stricker, Jennifer L. Agee, Le H. Kieu, Evangelos KakourosCarbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error
Tropical and sub-tropical wetlands are considered to be globally important sources for greenhouse gases but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are often difficAuthorsPaul H. Glaser, John C. Volin, Thomas J. Givnish, Barbara C. S. Hansen, Craig A. StrickerBenthic macroinvertebrate and fish communities in Lake Huron are linked to submerged groundwater vents
Groundwater can be an important source of nutrients and energy to aquatic ecosystems, but quantifying the inputs and biogeochemical importance remains challenging. A series of submerged groundwater vents in northern Lake Huron were examined to determine the linkage between groundwater nutrients and aquatic food webs. We collected samples of key food-web components from groundwater vent and referenAuthorsSanders T. Garrison, B.A. Biddanda, Craig A. Stricker, S.C. NoldIsotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008
Principal functions of the Mineral Resources Program are providing information to decision-makers related to mineral deposits on federal lands and predicting the environmental consequences of the mining or natural weathering of those deposits. Performing these functions requires that predictions be made of the likelihood of undiscovered deposits. The predictions are based on geologic and geoenviroAuthorsR. O. Rye, C.A. Johnson, G. P. Landis, A. H. Hofstra, P. Emsbo, C. A. Stricker, A.G. Hunt, B.G. Rusk