摘要
有机碳是陆地水生生态系统碳循环重要组成部分,湿地在维持岩溶碳汇稳定性方面具有十分重要的作用,揭示岩溶湿地水体中的有机碳时空分布特征及来源有助于明晰岩溶流域碳循环过程。本文以贵州威宁草海岩溶湿地为研究对象,对其丰、枯水期湿地水中溶解有机碳(DOC)、颗粒有机碳(POC)含量以及颗粒有机质(POM)碳、氮同位素等指标的测定,分析草海湿地水中POC、DOC浓度时空分布特征,探讨了水体中有机碳的来源。结果表明:草海湿地水体有机碳总体上以DOC为主,丰水期DOC变化范围为4.25~12.58 mg/L,平均值为8.19±1.49 mg/L,枯水期变化范围为4.79~15.93 mg/L,平均值为8.78±3.01 mg/L,丰水期略低于枯水期,DOC来源较为复杂,不同水文期受到外源和内源不同程度的影响;DOC在空间上丰水期呈现西部偏低,东及东南部偏高的分布特征,枯水期呈现南及西南部偏低,北及东北部偏高的分布特征。草海湿地水体丰水期POC变化范围为0.35~3.39 mg/L,平均值为1.13±0.78 mg/L,枯水期变化范围为0.32~1.84 mg/L,平均值为0.79±0.35 mg/L,丰水期高于枯水期;POC在空间上两期都呈现出中西低、中东高的分布特征。丰水期颗粒有机质的δ^(13)C、δ^(15)N值变化范围分别为-30.13‰~-14.80‰和-9.69‰~4.72‰,平均值分别为(-22.54±2.78)‰和(-2.88±2.89)‰,该时期POC以陆源有机质贡献为主;枯水期颗粒有机质的δ^(13)C、δ^(15)N值变化范围分别为-29.13‰~-21.91‰和-0.14‰~9.15‰,平均值分别为(-25.12±2.04)‰和(3.23±1.78)‰,该时期POC主要来源于沉积物。
Organic carbon is an important component in the carbon cycle of terrestrial aquatic ecosystems,and wetlands play a very important role in maintaining the stability of karst carbon sinks.Revealing the spatial and temporal distribution characteristics and sources of organic carbon in karst wetland water can help to clarify the carbon cycling process in karst watersheds.In this paper,the dissolved organic carbon(DOC)and particulate organic carbon(POC)contents,as well as particulate organic matter(POM)carbon and nitrogen isotopes were measured in the wetland water of Caohai wetland during the wet and dry periods,and the spatial and temporal distribution characteristics of POC and DOC concentrations in the water of Caohai wetland were analyzed to explore the sources of organic carbon in the water.The results showed that the organic carbon in the water column of Caohai wetland was mainly of DOC,and the range of DOC was from 4.25 to 12.58 mg/L with the mean value of 8.19±1.49 mg/L in the wet period and 4.79-15.93 mg/L with the mean value of 8.78±3.01 mg/L in the dry period,which was slightly lower than that in the dry period.The source of DOC is complex,and it is affected by exogenous and endogenous in different hydrological periods;spatially,the distribution of DOC is low in the west and high in the east and southeast in the wet period,and low in the south and southwest and high in the north and northeast in the dry period.The range of POC in Caohai wetland was 0.35-3.39 mg/L with a mean value of 1.13±0.78 mg/L during the wet period and 0.32-1.84 mg/L with a mean value of 0.79±0.35 mg/L during the dry period,which was higher than that in the dry period.Theδ^(13)C andδ^(15)N values of particulate organic matter in the abundant water period varied from-30.13‰to-14.80‰and-9.69‰to 4.72‰,with mean values of(-22.54±2.78)‰and(-2.88±2.89)‰,respectively,and the POC in this period was mainly contributed by terrestrial organic matter.Theδ^(13)C andδ^(15)N values of particulate organic matter in the dry perio
作者
李凯
曹星星
吴攀
杨诗笛
刘闪
廖家豪
LI Kai;CAO Xingxing;WU Pan;YANG Shidi;LIU Shan;LIAO Jiahao(School of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Karst Geological Resources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2022年第2期171-183,共13页
Earth and Environment
基金
国家自然科学基金项目(41807376)
贵州大学人才引进项目(贵大人基合字(2019)24号)
贵州省人才基地项目(RCJD2018-21)
贵州省科技计划项目(黔科合平台人才[2018]5781号)
喀斯特地质资源与环境教育部重点实验室开放课题(KST2017K06)。
关键词
DOC
POC
POM碳、氮同位素
时空分布
DOC
POC
POM carbon and nitrogen isotopes
temporal and spatial distribution
