Water Runoff Affects Carbon “Locked” Into Plants

Pacific Northwest National Laboratory Scientists Found that Important Aspects of Water's Movement Over the Surface and Through the Subsurface Have Consequences for Carbon Cycle Modeling
The starting point very often changes the finish. A team led by researchers at Pacific Northwest National Laboratory modeled runoff, that is, water's movement over the land surface and through the subsurface, using two widely adopted methods. They found that the modeling choices result in differences that ultimately swing results in carbon cycle simulations—by as much as 20 percent. The differences in modeling runoff methods cause substantial differences in the soil moisture that also changes soil temperature. Their study was published in theJournal of Advances in Modeling Earth Systems.
Why It Matters: Moisture is an important element in making sure the planet provides adequate food and water is plentiful. It is also a vital ingredient for the climate system-an important component of the Earth's water cycle. By influencing the amount of water available to evaporate or be taken up by plants, soil moisture is vital for the water and energy cycles, and in turn affects carbon through interactions that occur in the soils and plants.
Methods : The impacts of soil moisture on the carbon cycle are well known from previous research. However, interactions among soil moisture, groundwater, and runoff are typically neglected or greatly oversimplified in model simulations. Researchers in this study investigated how the choice of the runoff generation design influences the carbon cycle through changes in soil moisture and other land surface and subsurface states. In the current generation of land models, the uncertainty in hydrologic representations with coupled hydrologic, ecologic, and biogeochemical processes can lead to a large range of soil moisture results and subsequently the land carbon cycle. This variable range could translate into large consequences for long-term climate projections.
Source:Pacific Northwest National Laboratory

It is the fact that that majority of the species grown can sustain the drought more effectively than the excess moisture situations; especially on uplands and semiarid/arid regions. The study will definitely be useful to tailor the management practices for developing ecologically as well as economically viable agroecosystems for a particular various regions differing in climate.

Commented on September 2, 2014 05:14 by Govind Bharad, Retired from Agriculture University (May 1999) after serving as Asstt. Professor to Vice Chancellor, for period of 35 years. - Consultancy