期刊
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
卷 114, 期 -, 页码 -出版社
AMER GEOPHYSICAL UNION
DOI: 10.1029/2008JG000863
关键词
-
资金
- CIRC postdoctoral fellowship
Permafrost degradation can result in the loss of significant amounts of carbon, through release to the atmosphere in the form of carbon dioxide and/or methane and through export downstream to lakes and rivers. The fate of this carbon in lake ecosystems is poorly understood. We investigated the capacity of lake bacteria to utilize carbon from different soils from an adjacent mire. Dark bioassays were undertaken to measure the dynamics of the bioavailability and chemical character of dissolved organic carbon (DOC). The soils ranged from already degraded minerotrophic fens to ombrotrophic active layer and soils from the permafrost layer. Our study shows that soil DOC was rapidly consumed by bacteria collected from lake water, particularly within the first 48 h (about 85% of the total consumed DOC). The mean DOC consumption by lake bacteria was 0.087 mg L-1 d(-1) when supplied with lake water DOC and varied between 0.382 mg L-1 d(-1) (permafrost soil) and 0.491 mg L-1 d(-1) (degraded fen soil) when supplied with terrestrial DOC. Thus, the data suggest that export of DOC from degrading permafrost mires at any stage of degradation can potentially increase rates of respiration by fourfold to sevenfold and can have pronounced effects both on receiving lake ecosystems and on the land-atmosphere carbon balance. In this study we also propose simple predictive models, incorporating weight-averaged molecular weight and specific UV absorption in combination with other simple qualitative parameters for the estimation of potential bioavailability of soil DOC in aquatic ecosystems.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据