Net ecosystem production in the great lakes basin and its implications for the North American missing carbon sink: A hydrologic and stable isotope approach

详细信息	查看全文 | 推荐本文 |

• 作者：A. Karim ; J. Veizer ; J. Barth
• 关键词：stable isotopes ; water balance ; Net Ecosystem Production (NEP) ; Net Primary Production (NPP) ; Great Lakes
• 刊名：Global and Planetary Change
• 出版年：2008
• 期刊代码：35_09218181
• 类别：env
• 出版时间：March 2008
• 卷：61
• 期：1-2
• 页码：15-27
• 文件大小：597 K

摘要

This study resolves the Great Lakes Basin (GLB) hydrologic cycle into its components using stable isotopes of hydrogen and oxygen together with long term meteorological data. The results are used to calculate basinwide Net Primary Production (NPP). Stoichiometric relations of carbon and water during photosynthesis form the basis of computing NPP. Mean annual discharge from the GLB is 29%of the precipitation flux and in δD–δ¹⁸O space it has a slope of 5.6, distinctly lower than the 7.5 average slope for precipitation in the basin. Mean annual evaporation flux to the atmosphere from water bodies, soils, and wet canopies is 24%of the precipitation flux. Transpiration however, is the strongest pathway for loss of water from the basin, annually returning 342 Pg (petagram = 10¹⁵ g) or 47%of the precipitation flux to the atmosphere.