Forests, climate, and silicate rock weathering

Over time periods of 10(6) years and longer, atmospheric carbon dioxide content is largely controlled by a balance between silicate rock weathering and CO2 sources (degassing from the Earth plus net organic carbon oxidation). Vegetation cover can affect silicate rock weathering rates by increasing soil CO2 content, stabilizing soil cover, and producing organic acids. Forests absorb more solar radiation than most other ecosystems; this tends to warm Earth's climate, especially outside of the tropics; this warmth would tend to increase silicate rock weathering rates. Here, we develop preliminary parameterizations of this effect that could be incorporated into carbonate-silicate cycle models, based on the results of general circulation model simulations. (c) 2005 Published by Elsevier B.V.