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Terrestrial carbon sequestration potential is widely considered as a realistic option for mitigating greenhouse gas emissions. However, this potential may be threatened by global changes including climate, land use, and management changes such as increased corn stover harvesting for rising production of cellulosic biofuel. Therefore, it is critical to investigate the dynamics of soil organic carbon (SOC) at regional or global scale. This study simulated the corn production and spatiotemporal changes of SOC in the U.S. Temperate Prairies, which covers over one-third of the U.S. corn acreage, using a biogeochemical model with multiple climate and land-use change projections. The corn production (either grain yield...
Soil organic carbon (SOC) storage plays a major role in the global carbon cycle and is affected by many factors including land use/management changes (e.g., biofuel production-oriented changes). However, the contributions of various factors to SOC changes are not well understood and quantified. This study was designed to investigate the impacts of changing farming practices, initial SOC levels, and biological enhancement of grain production on SOC dynamics and to attribute the relative contributions of major driving forces (CO2 enrichment and farming practices) using a fractional factorial modeling design. The case study at a crop site in Iowa in the United States demonstrated that the traditional corn-soybean (CS)...
* • Relative abundances of carbon and nitrogen isotopes in fungal sporocarps are useful in assessing mycorrhizal or saprotrophic status, and might provide insights into the evolutionary history of these traits. * • Sporocarps of known mycorrhizal or saprotrophic genera were collected at Woods Creek, OR, USA, and isotopically compared with foliage, litter, soils and wood collected from the same site. Possible trophic strategies were then isotopically assessed in archived specimens of the Pezizales of known molecular phylogeny from the western United States. * • At Woods Creek, mycorrhizal fungi were 3.5‰ ± 0.6‰ depleted in δ13C and 5.7‰ ± 0.4‰ enriched in δ15N compared with saprotrophic fungi. By...
A simple dynamic model (CBUDGET) was developed to quantify long-term carbon (C) dynamics in croplands. By using independent datasets (on continuous wheat) from the Waite Permanent Rotation Trial (Australia) and from Northwest Ohio, the tests of its performance resulted in R2 values of 0.85 and 0.80, respectively, between observed and simulated values. Our model suggests that the rate of residual C addition into the soil is the primary factor that controls soil organic carbon (SOC) storage for Ohio croplands under continuous corn, wheat and oats for the period 1866–1996 and continuous soybean for the period of 1924–1996. The interaction of CO2-fertilization and a temperature increase of 0.5°C decreased mean SOC levels...
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Inland wetlands produce, biogeochemically process and sequester carbon. Wetlands that are hydrologically connected to stream and river networks are commonly considered to be major sources of carbon that may be biologically or photochemically processed in-stream, or exported to coastal regions. However, very little is known about the potential or actual lateral carbon fluxes from different major wetland types, or the downstream fate of that carbon (rapid decomposition vs. sequestration vs. export). Major questions: What is the variability in potential carbon sources (as dissolved organic C, dissolved inorganic C, CO2 and CH4) from major inland wetland types to inland waters? What metrics and/or markers (chemical,...
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Our research focuses on assessing the components of the Net Ecoystem Carbon Balance using the eddy covariance approach to measure atmospheric fluxes of heat, energy, carbon dioxide and methane and testing equipment and techniques to measure the tidal exchange of dissolved organic (DOC) and inorganic carbon (DIC). The atmospheric flux tower is located south of Solano Land Trust's Rush Ranch, a working ranch encompassing 2,070 acres of marsh and rolling grasslands that provides both recreational and educational experiences for the public (http://www.solanolandtrust.org/RushRanch.aspx). Lateral fluxes are being collected at the San Francisco Bay National Estuarine Research Reserve First Mallard water quality station...
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The disturbance team contributes to the goals of the LandCarbon project and conducts research focusing on 3 main components: (1) monitoring disturbance patterns and their impacts on carbon cycling, (2) understanding drivers creating the patterns and impacts, and (3) using scenarios of change to project future potential disturbance patterns, their interactions with other disturbances, and subsequent impacts on carbon cycling. Key research questions driving our work include: (1) Monitoring: How can remotely sensed, field-based, and other data best be used individually and synergistically to track changes in fire occurrence in ecosystem types with long fire-return intervals and the impacts on carbon? How do disturbances...
Forest carbon stocks and fluxes vary with forest age, and relationships with forest age are often used to estimate fluxes for regional or national carbon inventories. Two methods are commonly used to estimate forest age: observed tree age or time since a known disturbance. To clarify the relationships between tree age, time since disturbance and forest carbon storage and cycling, we examined stands of known disturbance history in three landscapes of the southern Rocky Mountains. Our objectives were to assess the similarity between carbon stocks and fluxes for these three landscapes that differed in climate and disturbance history, characterize the relationship between observed tree age and time since disturbance...


    map background search result map search result map Ecosystem disturbances monitoring an modeling Inland wetlands Suisun Marsh, CA:  Net Ecosystem Carbon Balance Suisun Marsh, CA:  Net Ecosystem Carbon Balance Inland wetlands Ecosystem disturbances monitoring an modeling