Carbon Dioxide

CO2 emissions to the atmosphere from soils with natural plant vegetation approximately balance the atmospheric CO2 uptake by green terrestrial plants (no net increase of atmospheric CO2). In recent years, anthropogenic (e.g., agricultural) land-use has resulted in a significant net increase of land-to-atmosphere C flux by 1.5 gigatons of C annually. A rapidly growing world population combined with dwindling fossil fuel resources are significantly increasing pressure to use land for agricultural production (i.e., food, feed and biomass for bioenergy generation), and thus, further accelerate the net increase of C flux from soils to the atmosphere. Although significant progress has been made toward identifying CO2 sources and sinks, the Earth ecosystem is highly complex and cycling of organic C is tightly interconnected with the cycling of other elements, including nitrogen (N).

The incomplete knowledge of the biological processes that drive the global carbon (C) cycle, combined with the lack of understanding on how climate change (e.g., elevated CO2 concentrations, higher temperatures) affects these processes, limits our ability to forecast the effects and consequences of human activities. Therefore, it is pertinent to develop comprehensive understanding of the pathways and mechanisms involved in C turnover in soils and terrestrial ecosystems and to determine how these biological systems respond to climate change.  Presently, it is unclear how above-ground plants and below-ground microbial communities adapt and respond to climate change. Clearly, such knowledge is crucial for generating predictive flux models and applying soil management regimes to possibly reduce emissions of CO2 and other greenhouse gases.

Dr. Kostas KonstantinidisCEE Assistant Professor Kostas Konstantinidis, with support from the U.S. Department of Energy (DOE) and in collaboration with researchers at the University of Oklahoma, Michigan State University and University of Florida, is investigating the role of below-ground microbial communities for the decomposition of soil organic C. In particular, the DOE-funded project aims at performing system-level genomic analyses of microbial communities from Alaskan soils and soils of temperate regions to investigate how microorganisms adapt to increased atmospheric CO2 and temperature, especially with respect to release or sequestration of organic carbon. By studying soils from contrasting sites, Dr. Konstantinidis and the research team hope to synthesize all experimental data in climate change models to be applicable on a global scale.

Dr. Kostas Konstantinidis joined CEE in 2007 and established the Environmental Microbial Genomics Laboratory (Enve-omics Lab). The Enve-omics lab focuses on the smallest organisms on the planet, bacteria and archaea. These organisms represent the largest reservoir of biodiversity on Earth, drive the life-sustaining biogeochemical cycles, and cause or control diseases in humans, animals, and plants. His scientific interests are at the interface of microbial ecology with engineering and computational biology. The long-term goal of his research team is to broaden understanding of the genetic and metabolic diversity of microorganisms and to explore this biodiversity for biotechnological applications using both computational and wet-laboratory approaches such as bioinformatics, metagenomics, proteomics, genetics, and others. Dr. Konstantinidis and his team study both natural (e.g., freshwater, marine and soil) as well as engineered (e.g., bioremediation-related) microbial communities.

For additional information about this initiative, please visit: http://enveomics. gatech.edu/