Fast mineralization of land-born C in inland waters: first experimental evidences of aquatic priming effect
Fast mineralization of land-born C in inland waters: first experimental evidences of aquatic priming effect
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DOI：
10.1007/s10750-013-1635-1
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发表时间：
2014-01-01
期刊：
影响因子：
2.6
通讯作者：
Lacroix, Gerard
中科院分区：
文献类型：
--
作者：
Guenet, Bertrand;Danger, Michael;Lacroix, Gerard
在全球变化的背景下，侵蚀的土壤碳命运及其对水生生态系统二氧化碳排放的影响引起了激烈的争论。特别是，土壤碳矿化可以通过其与本土碳的相互作用来增强，这一过程称为启动效应，但该过程的实验证据很少。我们在模拟弱中营养和富营养水生条件的微观实验中测量了不同生态系统中采样的土壤有机质 (SOM) 的矿化速度与土壤层内的矿化速度相比。对于这两种营养负荷，将 C-13-葡萄糖添加到一半的微观世界中，以模拟浮游植物分泌的不稳定有机物 (LOM)。 LOM 对土壤矿化的影响是利用 SOM 和葡萄糖之间的 delta C-13 差异来估计的。孵化 45 天后，水生环境中的平均 SOM 矿化增加了 63%，这是孵化第一天出现的最重要的二氧化碳通量。营养素对 SOM 矿化没有显着影响，添加葡萄糖使 SOM 矿化平均增加 12%，证明了启动效应的发生。
In the context of global change, eroded soil carbon fate and its impact on aquatic ecosystems CO2 emissions are subject to intense debates. In particular, soil carbon mineralization could be enhanced by its interaction with autochthonous carbon, a process called priming effect, but experimental evidences of this process are scarce. We measured in a microcosm experiment simulating oligo-mesotrophic and eutrophic aquatic conditions how quickly soil organic matter (SOM) sampled in diverse ecosystems was mineralized as compared to mineralization within soil horizons. For both nutrient loads, C-13-glucose was added to half of the microcosms to simulate exudation of labile organic matter (LOM) by phytoplankton. Effects of LOM on soil mineralization were estimated using the difference in delta C-13 between the SOM and the glucose. After 45 days of incubation, the mean SOM mineralization was 63% greater in the aquatic context, the most important CO2 fluxes arising during the first days of incubation. Nutrients had no significant effect on SOM mineralization and glucose addition increased by 12% the mean SOM mineralization, evidencing the occurrence of a priming effect.