Our classic view of soil organic matter is that it is a penecontemporaneous mixture in which an aged, diagenetically altered component (humic material) is derived from previous inputs of photosynthetically-derived material. In reality, particulate organic carbon (POC) in surficial environments (both soils and sediments) is a mixture that can be fundamentally resolved into three general categories: contemporary (recently fixed C), aged (century to millennial time scale) and ancient (millions of years old).
The future availability and security of our managed water, energy, and land resources is of paramount importance. There is increasing concern that human-induced changes will alter and exceed the background variability caused by the contemporary environment. A climacteric challenge is to identify where and when these resources become substantially limited in the coming decades and what are the primary drivers.
Currently, because of changing climate conditions; changing use demands; new use technologies; emphasis on habitat conservation, public use, solitude, and cultural site preservation; and a plethora of other demands, the Bureau of Land Management (BLM) has challenges beyond cumulative effects. One major challenge is how these many demands inform objectives in our Land Use Plans that are measurable, meaningful, and realistic.
South America’s soils contain 10.3% of the carbon stock of the world soils. South America is home to 5.67% of the world population, and it accounts for 8.64% of the world food production and 21% of the meat production. Low-carbon agriculture can offset anthropogenic emissions and increase annual food production in South America by about 10%.
Water is critical, not only to meet personal water needs but to generate the energy to drive a healthy economy and to meet the challenges of food for an ever-growing world population. Increased climate variability and conflicting demands for water require us to fundamentally rethink how we should manage our limited groundwater and surface water resources so that energy production and economic vitality does not come at the cost of potable water availability, food security and environmental quality.
Contact and imaging spectroscopy show great promise for measurement of the physiology of ecosystems related both to environmental drivers and genetics. Over the last decade, researchers have demonstrated the use of reflectance spectroscopy to rapidly and accurately characterize features of ecosystems that previously entailed considerable monetary expense and effort, and/or were not thought to be mappable.
The Arctic has experienced much greater warming than the global average in recent decades. Current climate models project that this Arctic warming trend will continue in this century. At present, one quarter of its land is underlain with permafrost and contains a large amount of vulnerable carbon.
Extensive seasonal biomass burning over southern Africa results in the transport of massive amounts of smoke aerosols over the adjacent Atlantic Ocean. These aerosols are of increasing interest due to their strong absorption of incoming solar radiation and the associated impact on the regional energy budget and the atmosphere thermodynamical structure. Interactions between the overlying smoke aerosols and low-level cloud microphysics and the subsequent albedo perturbation are, however, generally ignored in biomass burning radiative assessments.
Accurate prediction of high resolution (1-10 km) regional convection and rainfall is vital for a wide variety of meteorological applications. To improve the understanding and the model simulation of the regional convection and precipitation, a three-pronged strategy was undertaken. This include studying the impacts of heterogeneous land surface, (ii) land-atmosphere surface coupling strength, and (iii) an improvement to the Kain-Fritsch (KF) convective parameterization scheme (CPS), on short-term precipitation forecasting using the Weather Research and Forecasting (WRF) model.
As our values evolve and the world changes, we sometimes face problems of increasing complexity where status quo solutions are no longer acceptable or applicable. Computational and geospatial models provide an opportunity to investigate new ideas amidst an uncertain future, and to help us more fully understand potential effects and explore alternative solutions.
The spatial heterogeneity of land surface affects energy, moisture, and greenhouse gas exchanges with the atmosphere. However, representing heterogeneity of terrestrial hydrological and biogeochemical processes in earth system models remains a critical scientific challenge.