Filters: Tags: Soil carbon (X)34 results (32ms)
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)...
Categories: Publication; Types: Journal Citation; Tags: Carbon dynamics, Soil carbon, Soil organic carbon
Projection of corn production and stover-harvesting impacts on soil organic carbon dynamics in the U.S. Temperate Prairies
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...
Categories: Publication; Types: Journal Citation; Tags: Carbon dynamics, Carbon flux, Carbon stock, Soil carbon, Soil organic carbon,
Evaluation of a model framework to estimate soil and soil organic carbon redistribution by water and tillage using 137Cs in two U.S. Midwest agricultural fields
Cultivated lands in the U.S. Midwest have been affected by soil erosion, causing soil organic carbon (SOC) redistribution in the landscape and other environmental and agricultural problems. The importance of SOC redistribution on soil productivity and crop yield, however, is still uncertain. In this study, we used a model framework, which includes the Unit Stream Power-based Erosion Deposition (USPED) and the Tillage Erosion Prediction (TEP) models, to understand the soil and SOC redistribution caused by water and tillage erosion in two agricultural fields in the U.S. Midwest. This model framework was evaluated for different digital elevation model (DEM) spatial resolutions (10-m, 24-m, 30-m, and 56-m) and topographic...
Categories: Publication; Types: Journal Citation; Tags: Cs-137, Deposition, Erosion, Midwest United States, Soil carbon,
? Rhizodeposition, or the addition of C from roots to soil C pools, is expected to increase if net primary production is stimulated and some excess C is allocated below-ground. We investigated the effects of 5 yrs of elevated CO2 on below-ground C dynamics in a native, C3?C4 grassland ecosystem in Colorado, USA. ? Cylinder harvests following each growing season and monolith excavation at the end of the experiment provided data on root biomass, root C : N ratios, and root and soil ?13C values. We applied an isotopic mixing model to quantify new soil C inputs on elevated and ambient CO2 treatments. ? Root biomass increased by 23% and root C : N ratios increased by 26% after 5 yrs of elevated CO2. Species-specific...
Categories: Publication; Types: Citation, Journal Citation; Tags: 13C/12C, C : N ratio, New Phytologist, elevated CO2, rhizodeposition,
Soils play a key role in the global cycling of carbon (C), storing organic C, and releasing CO2 to the atmosphere. Although a large number of studies have focused on the CO2 flux at the soilâ€“air interface, relatively few studies have examined the rates of CO2 production in individual layers of a soil profile. Deeper soil horizons often have high concentrations of CO2 in the soil air, but the sources of this CO2 and the spatiotemporal dynamics of CO2 production throughout the soil profile are poorly understood. We studied CO2 dynamics in six soil profiles arrayed across a grassland hillslope in coastal southern California. Gas probes were installed in each profile and gas samples were collected weekly or biweekly...
Categories: Publication; Types: Citation, Journal Citation; Tags: 14C, CO2 flux, Ecosystems, Springer New York, belowground processes,
Fire and hydrology can be significant drivers of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to disturbance. New methods are needed to understand the vulnerability and resilience of different landscapes to permafrost degradation. This project uses remote sensing, geophysical, and other field-based observations to reveal details of both near-surface (<1 m) and deeper (>1 m) permafrost characteristics over multiple scales. This LandCarbon project currently supports the NASA ABoVE project, 'Vulnerability of inland waters and the aquatic...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Alaska, Carbon Stock, Disturbance, Geophysics, Permafrost,
Total belowground carbon flux in subalpine forests is related to leaf area index, soil nitrogen, and tree height
In forests, total belowground carbon (C) flux (TBCF) is a large component of the C budget and represents a critical pathway for delivery of plant C to soil. Reducing uncertainty around regional estimates of forest C cycling may be aided by incorporating knowledge of controls over soil respiration and TBCF. Photosynthesis, and presumably TBCF, declines with advancing tree size and age, and photosynthesis increases yet C partitioning to TBCF decreases in response to high soil fertility. We hypothesized that these causal relationships would result in predictable patterns of TBCF, and partitioning of C to TBCF, with natural variability in leaf area index (LAI), soil nitrogen (N), and tree height in subalpine forests...
Categories: Publication; Types: Journal Citation; Tags: Carbon flux, Leaf area index, Soil carbon, Soil nitrogen, Subalpine forests,
The Great Dismal Swamp (GDS) project is an application of USGS LandCarbon, at the US Fish and Wildlife Service's (FWS) Great Dismal Swamp National Wildlife Refuge (NWR), and is designed to produce local-scale carbon estimates (including fluxes, ecosystem balance, and long-term sequestration rate) to include in an ecosystem service assessment in support of Department of Interior (DOI) land management activities. The project will improve the understanding of the effects of past drainage, logging, farming, and management on carbon sequestration and fire risk in peatlands. Broad Science Questions: How are ecosystem services (including carbon sequestration, wildlife viewing, water quality, and others) impacted by management...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Atlantic White Cedar, Carbon Flux, Carbon Stock, Disturbance, Ecosystem Services,
The Biologic Carbon Sequestration Assessment Program (LandCarbon) is designed to support the following goals: Assess the current and potential carbon balance (stocks and fluxes) in major terrestrial and aquatic ecosystems Evaluate the effects of both natural and anthropogenic driving forces on ecosystem carbon balance and greenhouse gas fluxes Develop carbon monitoring methods and capabilities Conduct research and provide science support for increasing carbon sequestration in land management policies and practices The LandCarbon Community serves as a content management system for the LandCarbon Data Portal. This Data Portal is an effort to catalog and provide access to data and information from a range of LandCarbon...
Soil Respiration in the Cold Desert Environment of the Colorado Plateau (USA): Abiotic Regulators and Thresholds
Abstract Decomposition is central to understanding ecosystem carbon exchange and nutrient-release processes. Unlike mesic ecosystems, which have been extensively studied, xeric landscapes have received little attention; as a result, abiotic soil-respiration regulatory processes are poorly understood in xeric environments. To provide a more complete and quantitative understanding about how abiotic factors influence soil respiration in xeric ecosystems, we conducted soil- respiration and decomposition-cloth measurements in the cold desert of southeast Utah. Our study evaluated when and to what extent soil texture, moisture, temperature, organic carbon, and nitrogen influence soil respiration and examined whether...
Categories: Publication; Types: Citation, Journal Citation; Tags: Biogeochemistry, Cold deserts, Regression tree, Soil carbon, Soil respiration
When agricultural land is no longer used for cultivation and allowed to revert to natural vegetation or replanted to perennial vegetation, soil organic carbon can accumulate. This accumulation process essentially reverses some of the effects responsible for soil organic carbon losses from when the land was converted from perennial vegetation. We discuss the essential elements of what is known about soil organic matter dynamics that may result in enhanced soil carbon sequestration with changes in land-use and soil management. We review literature that reports changes in soil organic carbon after changes in land-use that favour carbon accumulation. This data summary provides a guide to approximate rates of SOC sequestration...
Categories: Publication; Types: Citation, Journal Citation; Tags: Global Change Biology, carbon sequestration, land-use, reforestation, soil carbon
Understanding the Impacts of Permafrost Change: Providing Input into the Alaska Integrated Ecosystem Model
Ongoing climate change has the potential to negatively impact Alaska’s ecosystems and the critical services that they provide. These ecosystem services include supplying food and fiber for Alaskan communities, offering opportunities for recreational, cultural, and spiritual activities, and regulating temperature and water flow (runoff, flooding, etc.). Scientists build models to better understand processes and interactions in the natural environment and to use what we know to predict what will happen in the future, so that we can plan for it. Researchers from multiple institutions and disciplines developed an Integrated Ecosystem Model (IEM) for Alaska and Northwest Canada. The model helps forecast how climate...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 2011, Alaska, Alaska CASC, CASC, Completed,
This dataset contains measurements of chemical concentrations of soil samples representing 28 headwater drainage basins completely within the Adirondack Park of New York State (ADK Park), one basin partially in the ADK Park, and one watershed 2 kilometers from the ADK Park boundary. Seven of these watersheds have been sampled 2 or 3 times over periods of 12 to 22 years. Soil samples were collected from pit faces exposed by shoveling. Total mass of organic matter, carbon and nitrogen in the forest floor are also presented for 16 headwater drainage basins in the ADK Park. Forest floor mass data were determined from samples collected with soil corers. The presented data are organized by six projects: the Adirondack...
Categories: Data, Data Release - Revised; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Adirondack Park, Adirondack Park, New York, Ambient Monitoring, B horizon, B horizon,
Management intensity – not biodiversity – the driver of ecosystem services in a long-term row crop experiment
A positive role for biodiversity is assumed for managed ecosystems. We conducted a 12-year study of this sustainability principle, through separate manipulation of management intensity and crop diversity. The site was located in southwest Michigan, representative of rain-fed production, with high climate variability and well-drained soils. Provisioning services of grain and protein yield were monitored, simultaneous with supporting services of soil fertility, C and N, and regulating services associated with water quality (N-use efficiency and nitrate-N leached in gravimetric lysimeters). Surprisingly, a strong role for management was shown, and almost nil for crop diversity. Organic management (ORG) sustained soil...
Categories: Publication; Types: Citation; Tags: Crop diversity, Data Visualization & Tools, Landscapes, Nitrogen cycle, Northeast CASC,
What lies below? Improving quantification and prediction of soil carbon storage, stability, and susceptibility to disturbance.
Soils are a vast reservoir of organic carbon (C), rendering the fate of soil C an important control on the global climate system. Widespread changes in soil C storage capacity present a potentially strong feedback to global change. Yet, a comprehensive understanding of how soil C will respond to climate and/or land use disturbance remains illusive, resulting in major uncertainties in global climate models. Our working group will synthesize information on the processes controlling soil C storage across different spatial scales and develop new procedures to translate local measurements to the regional and global scale datasets used by models. These activities will improve our ability to map the vulnerability of soil...
Categories: Project; Tags: Active, All Working Groups, Carbon, Carbon storage, Ecosystems,
The MC2 model projects an overall increase in carbon capture in conterminous United States during the 21st century while also simulating a rise in fire causing much carbon loss. Carbon sequestration in soils is critical to prevent carbon losses from future disturbances, and we show that natural ecosystems store more carbon belowground than managed systems do. Natural and human-caused disturbances affect soil processes that shape ecosystem recovery and competitive interactions between native, exotics, and climate refugees. Tomorrow's carbon budgets will depend on how land use, natural disturbances, and climate variability will interact and affect the balance between carbon capture and release.
Categories: Publication; Types: Journal Citation; Tags: Climate change, Climate console, Climate projections, Dynamic global vegetation model, Fire,
A conceptual framework for estimating the climate impacts of land-use change due to energy crop programs
In this paper I discuss general conceptual issues in the estimation of the impacts of CO2 emissions from soils and biomass, over time, as a result of land-use change (LUC) due to increased demand for energy crops. The effect of LUC on climate depends generally on the magnitude and timing of changes in soil and plant carbon, and in particular on the timing and extent of the reversion of land to original ecosystems at the end of the bioenergy program. Depending on whether one counts the climate impacts of any reversion of land uses, and how one values future climate-change impacts relative to present impacts, one can estimate anywhere from zero to very large climate impacts due to land-use change (LUC). I argue that...
Categories: Publication; Types: Citation; Tags: Biofuels, Climate change, Land-use change, Lifecycle analysis, Net present value,
In regions subject to strong winds, considerable amounts of soil are transported off land and deposited to nearby fields and surface water. This study investigated the nutrient supply from deposition of erodible-sized soil to surrounding soil and surface water in a controlled laboratory setting. Wind-erodible fraction (WEF) aggregates were collected from a field with no manure or fertilizer application (Treatment WEF0) and a field that had received 180 Mg ha-1 year-1 of cattle manure (WEF180) for 30 years. The WEF aggregates were applied to a loamy sand soil and to distilled water at rates equivalent to 0, 10, 50, 100, and 150 Mg ha-1 and incubated for 2 years. Deposition of carbon and nutrient-enriched WEF aggregates...
Categories: Publication; Types: Citation, Journal Citation; Tags: Nitrogen, Soil Science, phosphorus, soil available N, soil carbon,
Linear and nonlinear effects of temperature and precipitation on ecosystem properties in tidal saline wetlands
Integrated climate and land use change scenarios for California rangeland ecosystem services: wildlife habitat, soil carbon, and water supply
We quantified baseline and projected change in wildlife habitat, soil organic carbon (SOC), and water supply (recharge and runoff). For six case study watersheds we quantified the interactions of future development and changing climate on recharge, runoff and streamflow, and precipitation thresholds where dominant watershed hydrological processes shift through analysis of covariance.
Categories: Publication; Types: Journal Citation; Tags: California, Climate change adaption, Downscaled global climate models, Ecosystem services, Grassland,