The Intergovernmental Panel on Climate Change (IPCC) Technical Paper Climate Change and Water draws together and evaluates the information in IPCC Assessment and Special Reports concerning the impacts of climate change on hydrological processes and regimes, and on freshwater resources – their availability, quality, use and management. It takes into account current and projected regional key vulnerabilities, prospects for adaptation, and the relationships between climate change mitigation and water. Its objectives are:

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Climate change and water.

The Environmental Protection Agency (EPA) provides access to information on a variety of topics related to the environment and strives to inform citizens of health risks. The EPA also has an extensive library network that consists of 26 libraries throughout the United States, which provide access to a plethora of information to EPA employees, scientists, and researchers. The EPA implemented a reorganization project to digitize their materials so they would be more accessible to a wider range of users, but this plan was drastically accelerated when the EPA was threatened with a budget cut. It chose to close and reduce the hours and services of some of their libraries. As a result, the agency was accused of denying users the “right to know” by making information unavailable, not providing an adequate strategic plan, and discarding vital materials. This case study explores the background of the digitization project, the practices implemented, and the critiques of the project.

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The Environmental Protection Agency

https://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf_files/0_Task1_Cover/Cover_TOC.pdf

Good Practice Guidance for Land Use, Land-Use Change and Forestry

Agricultural lands occupy 37% of the earth's land surface. Agriculture accounts for 52 and 84% of global anthropogenic methane and nitrous oxide emissions. Agricultural soils may also act as a sink or source for CO2, but the net flux is small. Many agricultural practices can potentially mitigate greenhouse gas (GHG) emissions, the most prominent of which are improved cropland and grazing land management and restoration of degraded lands and cultivated organic soils. Lower, but still significant mitigation potential is provided by water and rice management, set-aside, land use change and agroforestry, livestock management and manure management. The global technical mitigation potential from agriculture (excluding fossil fuel offsets from biomass) by 2030, considering all gases, is estimated to be approximately 5500–6000 Mt CO2-eq. yr−1, with economic potentials of approximately 1500–1600, 2500–2700 and 4000–4300 Mt CO2-eq. yr−1 at carbon prices of up to 20, up to 50 and up to 100 US$ t CO2-eq.−1, respectively. In addition, GHG emissions could be reduced by substitution of fossil fuels for energy production by agricultural feedstocks (e.g. crop residues, dung and dedicated energy crops). The economic mitigation potential of biomass energy from agriculture is estimated to be 640, 2240 and 16 000 Mt CO2-eq. yr−1 at 0–20, 0–50 and 0–100 US$ t CO2-eq.−1, respectively.

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Greenhouse gas mitigation in agriculture

Vesicular-arbuscular mycorrhizal fungi can affect the water balance of both amply watered and droughted host plants. This review summarizes these effects and possible causal mechanisms. Also discussed are host drought resistance and the influence of soil drying on the fungi.

Water relations, drought and vesicular-arbuscular mycorrhizal symbiosis

This essay summarizes deliberation by the Soil Science Society of America (SSSA) Ad Hoc Committee on Soil Quality (S-581) and was written to spur discussion among SSSA members Varying perceptions of soil quality have emerged since the concept was suggested in the early 1990s, and dialogue among members is important because, unlike air and water quality, legislative standards for soil quality have not been and perhaps should not be defined In simplest terms, soil quality is “the capacity (of soil) to function” This definition, based on function, reflects the living and dynamic nature of soil Soil quality can be conceptualized as a three-legged stool, the function and balance of which requires an integration of three major components — sustained biological productivity, environmental quality, and plant and animal health The concept attempts to balance multiple soil uses (eg, for agricultural production, remediation of wastes, urban development, forest, range, or recreation) with goals for environmental quality Assessing soil quality will require collaboration among all disciplines of science to examine and interpret their results in the context of land management strategies, interactions, and trade-offs Society is demanding solutions from science Simply measuring and reporting the response of an individual soil parameter to a given perturbation or management practice is no longer sufficient The soil resource must be recognized as a dynamic living system that emerges through a unique balance and interaction of its biological, chemical, and physical components We encourage SSSA members to consider the concept of soil quality (perhaps as a marketing tool) and to debate how it might enable us to more effectively meet the diverse natural resource needs and concerns of our rural, urban, and suburban clientele of today and tomorrow

https://www.rowan.k12.ky.us/userfiles/959/Classes/10689/Soil%20Quality.pdf

Soil Quality: A Concept, Definition, and Framework for Evaluation (A Guest Editorial)

Rangeland grazing management strategies have been developed in an effort to sustain efficient use of forage resources by livestock. However, the effects of grazing on the redistribution and cycling of carbon (C) and nitrogen (N) within the plant–soil system are not well understood. We examined the plant–soil C and N balances of a mixed-grass rangeland under three livestock stocking rates using an area that had not been grazed by domestic livestock for more than 40 years. We established nongrazed exclosures and pastures subjected to continuous season-long grazing at either a light stocking rate (20 steer-days/ha) or a heavy stocking rate (59 steer-days/ha, ∼50% utilization of annual production). Twelve years of grazing under these stocking rates did not change the total masses of C and N in the plant–soil (0–60 cm) system but did change the distribution of C and N among the system components, primarily via a significant increase in the masses of C and N in the root zone (0–30 cm) of the soil profile. The m...

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Impact of grazing management on the carbon and nitrogen balance of a mixed-grass rangeland

Concern over human impact on the global environment has generated increased interest in quantifying agricultural contributions to greenhouse gas fluxes. As part of a research effort called GRACEnet (Greenhouse Gas Reduction through Agricultural Carbon Enhancement Network), this paper summarizes available information concerning management effects on soil organic carbon (SOC) and carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) fluxes in cropland and rangeland in northwestern USA and western Canada, a region characterized by its inherently productive soils and highly variable climate. Continuous cropping under no-tillage in the region increased SOC by 0.27 0.19 Mg C ha 1 yr 1 , which is similar to the Intergovernmental Panel on Climate Change (IPCC) estimate for net annual change in C stocks from improved cropland management. Soil organic C sequestration potential for rangelands was highly variable due to the diversity of plant communities, soils, and landscapes, underscoring the need for additional long-term C cycling research on rangeland. Despite high variability, grazing increased SOC by 0.16 0.12 Mg C ha 1 yr 1 and converting cropland or reclaimed mineland to grass increased SOC by 0.94 0.86 Mg C ha 1 yr 1 . Although there was generally poor geographical coverage throughout the region with respect to estimates of N2O and CH4 flux, emission of N2O was greatest in irrigated cropland, followed by non-irrigated cropland, and rangeland. Rangeland and non-irrigated cropland appeared to be a sink for atmospheric CH4, but the size of this sink was difficult

Greenhouse gas contributions and mitigation potential of agricultural practices in northwestern USA and western Canada

https://jornada.nmsu.edu/bibliography/06-032.pdf

Monitoring ecological processes for restoration projects

We investigated the influence of long-term (56 years) grazing on organic and inorganic carbon (C) and nitrogen (N) contents of the plant–soil system (to 90 cm depth) in shortgrass steppe of northeastern Colorado. Grazing treatments included continuous season-long (May–October) grazing by yearling heifers at heavy (60–75% utilization) and light (20–35% utilization) stocking rates, and nongrazed exclosures. The heavy stocking rate resulted in a plant community that was dominated (75% of biomass production) by the C4 grass blue grama (Bouteloua gracilis), whereas excluding livestock grazing increased the production of C3 grasses and prickly pear cactus (Opuntia polycantha). Soil organic C (SOC) and organic N were not significantly different between the light grazing and nongrazed treatments, whereas the heavy grazing treatment was 7.5 Mg ha−1 higher in SOC than the nongrazed treatment. Lower ratios of net mineralized N to total organic N in both grazed compared to nongrazed treatments suggest that long-term grazing decreased the readily mineralizable fraction of soil organic matter. Heavy grazing affected soil inorganic C (SIC) more than the SOC. The heavy grazing treatment was 23.8 Mg ha−1 higher in total soil C (0–90 cm) than the nongrazed treatment, with 68% (16.3 Mg ha−1) attributable to higher SIC, and 32% (7.5 Mg ha−1) to higher SOC. These results emphasize the importance in semiarid and arid ecosystems of including inorganic C in assessments of the mass and distribution of plant–soil C and in evaluations of the impacts of grazing management on C sequestration.

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Gerald E. Schuman

Papers

Soil Quality: A Concept, Definition, and Framework for Evaluation (A Guest Editorial)

Impact of grazing management on the carbon and nitrogen balance of a mixed-grass rangeland

Greenhouse gas contributions and mitigation potential of agricultural practices in northwestern USA and western Canada

Monitoring ecological processes for restoration projects

Response of organic and inorganic carbon and nitrogen to long-term grazing of the shortgrass steppe.