湖泊科学2024，Vol.36Issue(5)：1425-1435,11.DOI:10.18307/2024.0523
鄱阳湖典型洲滩湿地土壤有机碳分解速率及温度敏感性
Decomposition rate and temperature sensitivity of soil organic carbon in a typical shoal wetland of Lake Poyang
摘要
Abstract
Temperature sensitivity of soil organic carbon decomposition(Q10)is a key parameter to predict the contribution of eco-system carbon cycle to global climate change.The hydrological rhythm of global wetlands is changing rapidly.However,little atten-tion has been paid to the effects of waterlogging differences on wetland soil Qt0.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)in-duced by different flooding duration in the East Lake marshland wetland of Lake Poyang.The decomposition rate of soil organic car-bon(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 water-flooding 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 mi-crobial 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 a-mong 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 in-creases of soil depth and flooding time.Results of correlation analysis and structural equation model showed that the main factors af-fecting 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.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Key words
Soil organic carbon/lakeshore wetland/temperature sensitivity/Fourier transform infrared spectroscopy/Lake Poyang引用本文复制引用
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[J].湖泊科学,2024,36(5):1425-1435,11.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. （32160308,42061022）
