Seasonal dynamics of carbon stable isotope ratios of particulate organic matter and benthic diatoms in strongly acidic Lake Katanuma
Seasonal dynamics of carbon stable isotope ratios of particulate organic matter and benthic diatoms in strongly acidic Lake Katanuma
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DOI：
10.3354/ame033087
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发表时间：
2003-08-21
影响因子：
1.4
通讯作者：
Shikano, S
中科院分区：
文献类型：
--
作者：
Doi, H;Kikuchi, E;Shikano, S
片沼湖是一个强酸性的火山湖（平均PH值2.2），位于日本东北部，仅发现2种藻类：虽然浮游植物的δ（13）C在湖泊生态系统中通常随季节变化，但片沼湖颗粒有机物的平均δ（13）C（POM，主要是浮游植物）被限制在千分之-26.4到-23.7的狭窄范围内。其主要原因是C.产于湖底的嗜酸菌。片沼湖中P. acidojaponica的δ（13）C随季节变化，与1 m和4 m深度的P. dcidojaponica丰度呈正相关。这表明，较高的P. acidojaponica生物量在1和4米产生的C-13-富集在高密度藻垫，因为有限的溶解CO2气体。片沼湖底栖硅藻的平均δ（13）C高于浮游植物，尽管硅藻似乎同化了湖水中相同的碳源（CO2气体）。
Lake Katanuma is a strongly acidic volcanic lake (average PH 2.2) located in NE Japan in which only 2 algal species are found: Pinnularia acidojaponica, a benthic diatom, and Chlamydomonas acidophila, a phytoplankton species, Although the delta(13)C of phytoplankton generally varies seasonally in lake ecosystems, in Lake Katanuma the mean delta(13)C of particulate organic matter (POM, mainly phytoplankton) is constrained to a narrow range from -26.4 to -23.7 parts per thousand. A major reason for this is the continuous supply of dissolved CO2 gas available to C. acidophila from fumaroles at the lake bottom. The delta(13)C of P. acidojaponica in Lake Katanuma varied seasonally and was positively correlated with P. dcidojaponica abundance at 1 and 4 m depths. This suggests that the higher P. acidojaponica biomass at 1 and 4 m produced the C-13-enrichment in the high-density algal mats because of the limited dissolved CO2 gas. The mean delta(13)C of benthic diatoms was higher than that of phytoplankton in Lake Katanuma, although the diatoms seemed to assimilate the same carbon source (CO2 gas) in the lake water.