Spotting zones of dissimilatory sulfate reduction in a forested catchment:: the 34S-35S approach
Spotting zones of dissimilatory sulfate reduction in a forested catchment:: the 34S-35S approach
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DOI：
10.1016/s0269-7491(00)00137-8
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发表时间：
2001-01-01
影响因子：
8.9
通讯作者：
Novak, M
中科院分区：
文献类型：
--
作者：
Alewell, C;Novak, M
森林流域硫酸盐还原位点的定位是非常重要的，因为异化硫酸盐还原可以是沉积硫酸盐的一个相当大的汇。为了确定德国巴伐利亚州东北部森林流域的同化硫酸盐还原位点，研究了流域内3个地点（高地、间歇渗漏、沼泽）土壤硫的S-34 δ深度剖面，并用S-35放射性标记测量了潜在硫酸盐还原率。稳定的硫同位素表明，在高原地区，好氧代谢是主要的过程，土壤硫的间歇渗透（δ S-34在+ 1.6 ~ + 9.0 ppm之间）和同化还原不是显著的硫酸盐汇。然而，S-35放射性标记的结果表明，在实验室条件下，高地土壤具有潜在的高硫酸盐还原率。土壤硫在S-34 （δ S-34在-6 ~ +2.6 ppm之间）显著减少。S-34和S-35的数据都表明，在这个地点，异化硫酸盐还原是一个持续的过程。S-34和S-35是互补的。虽然使用S-35的测量可以显示同化细菌硫酸盐还原的瞬时潜力，但δ S-34数据反映了特定部位同化或异化S代谢的长期优势。2001爱思唯尔科学有限公司版权所有。
The localization of sulfate reducing sites in forested catchments is of major importance, because dissimilatory sulfate reduction can be a considerable sink for deposited sulfate. To localize dissimilatory sulfate reduction sites in a forested catchment (northeastern Bavaria, Germany), three sites within the catchment (upland site, intermittent seep, fen) were investigated for delta S-34 depth profiles of soil sulfur and potential sulfate reduction rates were measured with S-35 radiolabeling. Stable sulfur isotopes indicate that aerobic metabolism is the dominant process on the upland site and the intermittent seep (delta S-34 Of soil sulfur between + 1.6 and + 9.0 parts per thousand) and dissimilatory reduction is not a significant sink for sulfate. However, results of the S-35 radiolabeling indicated for the upland site that the soil has potentially high sulfate reduction rates under laboratory conditions. Soil sulfur of the fen was markedly depleted in S-34 (delta S-34 between -6 and +2.6 parts per thousand). Both, S-34 and S-35 data indicated that dissimilatory sulfate reduction is an ongoing process on this site. The S-34 and S-35 approaches are complementary. While measurements using S-35 can show momentary potential for dissimilatory bacterial sulfate reduction, delta S-34 data reflect long-term predominance of either assimilatory or dissimilatory S metabolism at a particular site. (C) 2001 Elsevier Science Ltd. All rights reserved.