| 水库浮游细菌生产和呼吸过程代谢内外源有机碳研究 |
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| 引用本文： | 韩一萱,李彪,荀凡,高培鑫,毛振镀,陶晔,邢鹏.水库浮游细菌生产和呼吸过程代谢内外源有机碳研究[J].湖泊科学,2022,34(1):162-173. |
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| 作者姓名： | 韩一萱 李彪 荀凡 高培鑫 毛振镀 陶晔 邢鹏 |
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| 作者单位： | 中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008;中国科学院大学,北京100049,中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 |
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| 基金项目： | 国家自然科学基金项目（31670505，31722008）和中国科学院青年创新促进会项目（2014273）联合资助. |
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| 摘 要： | 全球气候变化和人类活动的加剧影响水生生态系统中溶解性有机碳(DOC)的种类和浓度.浮游细菌生产和呼吸过程对碳源变化的响应,可能影响水体乃至区域的碳循环特征.本研究选取了南京市11座中小型水库,利用碳稳定同位素技术和双端元混合模型定量分析浮游细菌在生产和呼吸代谢过程中对内外碳源的利用.依据DOC中内外碳源的比例,将11座水库划分为内源型水库(内源碳占比>50%)和外源型水库(外源碳占比>50%).内源型水库DOC浓度、叶绿素a浓度以及营养指数均显著高于外源型水库.分析发现,水体初级生产力提高显著促进了浮游细菌对内源DOC的代谢速率,内源型水库中浮游细菌生产利用内源碳速率提高,而外源型水库中浮游细菌呼吸分解内源碳速率提高.不仅如此,水体初级生产力提高促进外源型水库浮游细菌对DOC的总代谢速率.水体溶解性无机氮和磷与浮游细菌的呼吸作用存在显著的相关关系,内源型水库中随着营养盐浓度升高细菌呼吸作用减弱,而外源型水库中细菌呼吸作用增强.上述研究结果提示,以外源输入为主的水体,随着营养水平提高浮游细菌呼吸过程显著增加,可能引起温室气体释放通量增加.
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| 关 键 词： | 水体营养状态 溶解性有机碳 生产速率 异养呼吸速率 稳定同位素示踪 |
| 收稿时间： | 2021/4/14 0:00:00 |
| 修稿时间： | 2021/5/11 0:00:00 |
Metabolism of exogenous and endogenous dissolved organic carbon for bacterioplankton production and respiration in reservoirs |
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| Han Yixuan,Li Biao,Xun Fan,Gao Peixin,Mao Zhendu,Tao Ye,Xing Peng.Metabolism of exogenous and endogenous dissolved organic carbon for bacterioplankton production and respiration in reservoirs[J].Journal of Lake Science,2022,34(1):162-173. |
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| Authors: | Han Yixuan Li Biao Xun Fan Gao Peixin Mao Zhendu Tao Ye Xing Peng |
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| Institution: | State Key Laboratory of Lake and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;University of Chinese Academy of Sciences, Beijing 100049, P. R. China |
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| Abstract: | Global climate change and intensive anthropogenic activities are affecting the variety and contents of dissolved organic carbons (DOC) in the aquatic systems. The potential response of planktonic bacteria to the changing carbon sources could influence the characteristics of carbon cycling in local waterbodies and even regional areas. In this study, eleven small and medium reservoirs were selected to quantificationally analyze the utilization of exogenous and endogenous organic carbon during the bacterial production and respiration using the stable carbon isotope analysis and a two-source mixing model. The eleven reservoirs were subsequently classified into exogenous (exogenous DOC/DOC>50%) and endogenous (endogenous DOC/DOC>50%) reservoirs according to the ratio of the two kinds of DOC sources. Results indicated that the concentrations of DOC and chlorophyll-a (Chl.a) and trophic level index were significantly higher in the endogenous reservoirs than in the exogenous reservoirs. It was observed that the bacterial metabolic rates of endogenous DOC could be significantly elevated with increasing primary productivity in the reservoirs. Specifically, the metabolic rates of endogenous DOC were improved for bacterial production in the endogenous reservoirs and bacterial respiration in the exogenous reservoirs, respectively. Moreover, the overall bacterial metabolic rates of DOC were promoted in the exogenous reservoirs with increasing primary productivity. In addition, a significant relationship was observed between dissolved inorganic nitrogen/phosphorus and bacterial respiration, indicating that the bacterial respiration could be suppressed with increasing nutrition concentration in the endogenous reservoirs but be strengthened with increasing nutrition concentration in the exogenous reservoirs. These results suggested that the release flux of greenhouse gas can be increased owing to the improvement of bacterial respiration with the elevating eutrophication levels in the exogenous reservoirs. |
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| Keywords: | Aquatic trophic level dissolved organic carbon production rate heterotrophic respiration rate stable isotopic signature |
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