| 引用本文: | 刘洁,郑博福,徐志文,龚磊强,余定坤,詹慧英,沈瑞昌.鄱阳湖典型洲滩湿地土壤有机碳分解速率及温度敏感性.湖泊科学,2024,36(5):1425-1435. DOI:10.18307/2024.0523 |
| Liu Jie,Zheng Bofu,Xu Zhiwen,Gong Leiqiang,Yu Dingkun,Zhan Huiying,Shen Ruichang.Decomposition rate and temperature sensitivity of soil organic carbon in a typical shoal wetland of Lake Poyang. J. Lake Sci.2024,36(5):1425-1435. DOI:10.18307/2024.0523 |
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| 鄱阳湖典型洲滩湿地土壤有机碳分解速率及温度敏感性 |
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刘洁1,2,3, 郑博福1,3, 徐志文2,4, 龚磊强2,4, 余定坤2,4, 詹慧英2,4, 沈瑞昌1,2,3
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1.南昌大学, 鄱阳湖环境与资源利用教育部重点实验室, 生命科学学院流域生态学研究所, 资源与环境学院, 南昌 330031;2.江西鄱阳湖湿地保护与恢复国家长期科研基地, 江西鄱阳湖湿地生态系统国家定位观测研究站, 南昌 330031;3.江西生态文明研究院, 江西“两山”转化与生态产品价值实现研究示范国家级专家服务基地, 南昌 330031;4.江西省鄱阳湖国家级自然保护区管理局, 南昌 330031
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| 摘要: |
| 土壤有机碳分解的温度敏感性(Q10)是预测生态系统碳循环对全球气候变化的关键参数。全球湿地水文节律正在迅速变化,然而淹水差异对湿地土壤Q10的影响还较少受到关注。在淹水差异梯度上,土壤有机碳质量对Q10的调控机制也未明确。以鄱阳湖的东湖洲滩湿地为研究对象,在淹水时长差异诱导形成的3个植被群落样带(泥滩带、苔草带和芦苇带)各采集深度为0~10、10~20和20~30 cm的土壤,在实验室内测定不同温度(10、15、20、25、30 ℃)下各植被带3个深度土壤有机碳的分解速率,运用指数方程拟合Q10,探讨淹水时长梯度上土壤有机碳分解速率和Q10的变化规律。运用傅里叶变换红外光谱技术(FTIR)测定土壤有机物的官能团结构,结合土壤有机碳、可溶性有机碳和微生物碳等有机碳组分含量,明确土壤有机碳质量对Q10的影响机制。结果表明,在10、15、20、25、30 ℃的温度下,土壤有机碳分解速率的平均值分别为19.19、31.00、51.67、77.28和109.32 μg/(d·g)。各个植被带的土壤有机碳分解速率均随着土壤深度的增加而显著降低。然而,在3条植被带之间,只有0~10 cm的土壤有机碳分解速率存在显著差异(P=0.030),表现为芦苇带＞苔草带＞泥滩带。土壤Q10的平均值为2.48,没有受到植被带和土壤深度的显著影响。FTIR数据显示,随着土壤深度和淹水时长的增加,洲滩湿地易分解的脂肪类有机物比例逐渐下降,但难分解的芳香类有机物比例逐渐升高。相关分析和结构方程模型结果表明,土壤有机碳分解速率的主要影响因素为含水量、微生物碳含量、pH和营养盐含量等。土壤有机物官能团结构、pH和总氮等因素对土壤Q10有显著影响。表层土壤Q10与脂肪类有机物含量呈正相关,与芳香类有机物含量呈负相关。 |
| 关键词: 土壤有机碳 洲滩湿地 温度敏感性 傅里叶变换红外光谱 鄱阳湖 |
| DOI：10.18307/2024.0523 |
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| 基金项目:国家自然科学基金项目(32160308, 42061022)、江西省重点研发计划“揭榜挂帅”项目(20223BBG74S01)、江西省自然科学基金面上项目(20232BAB205018)和南昌大学江西省财政科技专项“包干制”试点示范项目(ZBG20230418020)联合资助。 |
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| Decomposition rate and temperature sensitivity of soil organic carbon in a typical shoal wetland of Lake Poyang |
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Liu Jie,Zheng Bofu,Xu Zhiwen,Gong Leiqiang,Yu Dingkun,Zhan Huiying,Shen Ruichang
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1.Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, Center for Watershed Ecology, School of Life Science and School of Resources and Environment, Nanchang University, Nanchang 330031, P. R. China;2.Jiangxi Institute of Ecological Civilization, National Expert Service Base for Research and Demonstration of the "Two Mountains" Transformation and the Eco-products Value Realization in Jiangxi Province, Nanchang 330031, P. R. China;3.Administration Bureau of Poyang Lake National Nature Reserve in Jiangxi Province, Nanchang 330031, P. R. China
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| Abstract: |
| Temperature sensitivity of soil organic carbon decomposition (Q10) is a key parameter to predict the contribution of ecosystem carbon cycle to global climate change. The hydrological rhythm of global wetlands is changing rapidly. However, little attention has been paid to the effects of waterlogging differences on wetland soil Q10. The regulation mechanism of soil organic carbon mass on Q10 in the differential waterlogging gradient is also unclear. In this study, soil samples of 0-10 cm, 10-20 cm and 20-30 cm were collected from three vegetation community transect zones (mudflat zone, Carex zone and Phragmites australis zone) induced by different flooding duration in the East Lake marshland wetland of Lake Poyang. The decomposition rate of soil organic carbon (SOC) at three depths in each vegetation zone under different temperatures (10, 15, 20, 25 and 30 ℃) was measured in the laboratory. The Q10 was fitted with exponential equation to explore the changes of SOC decomposition rate and Q10 across the waterflooding duration gradient. Fourier transform infrared spectroscopy (FTIR) was used to determine the functional group structure of Soil Organic matter. We also examined the SOC effects on Q10 and its components, including SOC, dissolved organic carbon and microbial biomass carbon. Results showed that the average SOC decomposition rates were 19.19, 31.00, 51.67, 77.28 and 109.32 μg/(d·g) at 10, 15, 20, 25 and 30 ℃, respectively. SOC decomposition rates significantly decreased with the increases of soil depth in all vegetation zones. However, there was a significant difference in the SOC decomposition rate only at the depth of 0-10 cm among the three vegetation zones (P=0.030), with an order of P. austrum>Carex>mudflat. The mean value of soil Q10 was 2.48, which was not significantly affected by vegetation zone and soil depth. FTIR data showed that the proportion of easily decomsolvable fatty organic matter gradually decreased, while the proportion of refractory aromatic organic matter gradually increased with the increases of soil depth and flooding time. Results of correlation analysis and structural equation model showed that the main factors affecting SOC decomposition rate were water content, microbial carbon content, pH, and nutrient content. The functional group structure of soil organic matter, pH and total nitrogen significantly affected soil Q10. Q10 in the surface soil was positively correlated with fatty organic matter and negatively correlated with aromatic organic matter. |
| Key words: Soil organic carbon lakeshore wetland temperature sensitivity Fourier transform infrared spectroscopy Lake Poyang |
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