摘要
天然湿地在全球碳循环中起重要作用,研究滨海湿地碳循环过程对评估沿海地区碳收支有重要意义。为了探索江苏盐城滨海湿地碳循环过程,利用静态箱法测定了该地互花米草(Spartina alterniflora)、芦苇(Phragmites australis)、盐地碱蓬(Suaeda salsa)湿地土壤呼吸,采用去除根系法分离了土壤异养呼吸与自养呼吸。结果表明,各植被类型土壤呼吸均有明显月际变化,夏季较高,冬季较低。不同植被类型土壤呼吸差异显著,互花米草湿地年均土壤呼吸最高,盐地碱蓬湿地最低。互花米草、芦苇、盐地碱蓬湿地年均土壤呼吸依次为210.7、174.7、115.3 mg CO2·m^-2·h^-1。其中,异养呼吸的贡献率分别为38.8%、35.9%、52.0%,自养呼吸的贡献率分别为61.2%、64.1%、48.0%。不同植被类型间植物生物量、土壤可溶性有机碳(DOC)含量和微生物生物量碳(MBC)均存在显著差异。相关分析与多元逐步回归结果进一步显示,地下生物量、土壤DOC含量与MBC是引起不同植被类型土壤呼吸差异的重要原因。对湿地-大气碳平衡的估算结果表明,互花米草、芦苇、盐地碱蓬湿地均为大气的碳汇,固碳能力分别为811.1、760.0、145.9 g C·m^-2·a^-1,互花米草湿地的固碳能力最强。
Natural wetlands play an important role in global carbon cycle. Understanding the carbon cycling in coastal wetlands has great significance for estimating the carbon budget of coastal areas. To explore the carbon cycling of Yancheng coastal wetland in Jiangsu Province,we measured soil respiration in three types of wetlands respectively dominated by Spartina alterniflora,Phragmites australis,and Suaeda salsa using the static chamber technique. The root removal method was used to measure soil autotrophic and heterotrophic respiration. The results showed that soil respiration in the three wetland types exhibited significant seasonal variations,with higher values in summer and lower values in winter. Soil respiration varied significantly across vegetation types,with the highest value in the S. alterniflora wetland and the lowest value in the S. salsa wetland. The annual average soil respiration in the S. alterniflora,P. australis,and S. salsa wetlands were 210.7,174.7,and 115.3 mg CO2·m-2·h-1,respectively. The contributions of heterotrophic respiration to CO2 emissions for the three vegetation types were 38.8%,35.9%,and 52.0%,respectively. The contributions of autotrophic respiration were 61. 2%,64. 1%,and 48.0%. There were significant differences in plant biomass,soil dissolved organic carbon (DOC)content,and microbial biomass carbon (MBC) among different vegetation types. The results of correlation analysis and stepwise regression showed that belowground biomass,soil DOC content and MBC were the main factors driving the variation of soil respiration across different vegetation types. The estimation of the wetland-atmosphere carbon balance showed that S. alterniflora,P.australis,and S. salsa wetlands were all sinks of atmospheric carbon,with carbon sequestration rates of 811.1,760.0,and 145.9 g C·m-2·a-1,respectively. Among all the wetlands,the S.alterniflora wetland had the highest sequestration rate.
作者
程寅瑞
查勇
陈丽娟
韦耿
CHENG Yin-rui;ZHA Yong;CHEN Li-juan;WEI Geng(School of Geography,Nanjing Normal University,Nanjing 210023,China;Key Laboratory of Virtual Geographic Environment(Nanjing Normal University),Ministry of Education,Nanjing 210023,China;Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,Nanjing 210023,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2020年第12期4090-4097,共8页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41671428)项目。
关键词
滨海湿地
互花米草
土壤呼吸
异养呼吸
碳平衡
coastal wetland
Spartina alterniflora
soil respiration
heterotrophic respiration
carbon balance