长白山月亮湾亚高山湿地生态系统碳氮储量沿水分梯度空间分异规律及机制  

Spatial differentiation and mechanism of carbon and nitrogen storage along water gradient in subalpine wetland ecosystem of Yueliangwan in Changbai Mountain

作　　者：崔雅如 牟长城[1] 姬文慧 郝鑫海 CUI Yaru;MU Changcheng;JI Wenhui;HAO Xinhai(Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education,Northeast Forestry University,Harbin 150040,China)

机构地区：[1]东北林业大学森林生态系统可持续经营教育部重点实验室,哈尔滨150040

出　　处：《生态学报》2024年第18期7977-7990,共14页Acta Ecologica Sinica

基　　金：国家自然科学基金重点项目(42230703);东北林业大学碳中和科学基金项目(HZX220100003)。

摘　　要：湿地在全球碳氮循环中具有重要作用,揭示高海拔湿地碳、氮储量空间分异规律有助于减少其碳氮储量估算的不确定性。采用相对生长方程法与碳/氮分析仪测定法,同步测定长白山月亮湾亚高山湿地沿水分梯度(生长季水位由23 cm降低至-20 cm)依次分布的6种天然沼泽类型(下半段湖泊水分梯度的草丛沼泽-C、芦苇沼泽-L、灌丛沼泽-G和上半段阶地水分梯度的下部-LNx、中部-LNz和上部-LNs生境的落叶松泥炭藓沼泽)的生态系统碳储量、氮储量(植被和土壤)及其相关环境因子(水位、土壤有机质、全氮和全磷等),揭示高海拔湿地生态系统碳、氮储存能力沿水分梯度的空间分异规律及其形成机制,并探寻碳氮在植被、土壤和生态系统尺度上的耦合关系。结果表明:(1)其植被碳储量(2.95—59.94 t/hm^(2))和氮储量(0.044—0.733 t/hm^(2))沿水分梯度均呈下半段恒定及上半段递增的规律性,故其植被碳氮在水平空间上存在强耦合性;(2)土壤碳储量(252.05—436.86 t/hm^(2))和氮储量(10.96—18.06 t/hm^(2))沿水分梯度呈双递减型或草丛沼泽和3类生境上的落叶松泥炭藓沼泽显著高于芦苇沼泽和灌丛沼泽的变化规律性,故其土壤碳氮在水平空间上耦合性较弱,但其土壤碳、氮储量在垂直空间上的耦合性相对较强且根据其碳、氮储量的垂直变化趋势是否完全一致可分为2种类型(完全耦合型(G和LNz土壤碳氮垂直变化趋势完全一致)和基本耦合型(C、L、LNx、LNs土壤碳氮垂直变化趋势仅在表层明显不同));(3)生态系统碳储量(258.35—464.89 t/hm^(2))和氮储量(11.05—18.21 t/hm^(2))沿水分梯度呈下半段递减和上半段恒定或草丛沼泽和3类生境上的落叶松泥炭藓沼泽显著高于芦苇沼泽和灌丛沼泽的变化规律性,故其生态系统碳氮存在较强的耦合性(上半段完全耦合及下半段耦合性减弱),且其生态系统碳、氮储量均以土壤占Wetlands play an important role in global carbon and nitrogen cycle.Revealing the spatial differentiation of carbon and nitrogen storage in high-altitude wetlands is helpful to reduce the uncertainty of carbon and nitrogen storage estimation.Relative growth equation method and carbon/nitrogen analyze method were used.The ecosystem carbon and nitrogen stocks(vegetation and soil)and their related environmental factors(water level,soil organic matter,total nitrogen,and total phosphorus,etc.)were measured synchronously in six natural swamp types(tussock swamp-C,reed swamp-L,shrub swamp-G in the lower part of the lake water gradient and larch sphagnum bogs in lower-LNx,middle-LNz and upper-LNs habitats of upper half terrace water gradient)distributed along the water gradient(the water level decreased from 23 cm to-20 cm in the growing season)in Yuelangwan subalpine wetland of Changbai Mountain.It aimed to reveal the spatial differentiation of carbon and nitrogen storage capacity along water gradient and its formation mechanism in high-altitude wetland ecosystems,and explore the coupling relationship of carbon and nitrogen at vegetation,soil and ecosystem scales.The results showed that:(1)vegetation carbon storage(2.95—59.94 t/hm^(2))and nitrogen storage(0.044—0.733 t/hm^(2))were constant in the lower part and increased in the upper part along the water gradient,so vegetation carbon and nitrogen were strongly coupled in the horizontal space.(2)Soil carbon storage(252.05—436.86 t/hm^(2))and nitrogen storage(10.96—18.06 t/hm^(2))showed a double decreasing pattern or tussock swamp and larch sphagnum bogs in 3 habitats were significantly higher than reed swamp and shrub swamp along the water gradient,so the coupling of soil carbon and nitrogen was weak in horizontal space.However,the coupling of soil carbon and nitrogen storage was relatively strong in vertical space,and there were two types according to whether the vertical change trends of carbon and nitrogen storage were completely consistent(fully coupled type(

关 键 词：高海拔 沼泽湿地 生态系统碳氮储量 空间分异规律 主控因子 

分 类 号：X171.1[环境科学与工程—环境科学]