黄河中游湿地优势植物水分利用的同位素研究  

Stable isotopes research on water sources of dominant plants in a river wetland at the middle reaches of the Yellow River

作　　者：许秀丽 李云良[3] 郭强 XU Xiu-li;LI Yun-liang;GUO Qiang(School of Geography,Jiangsu Second Normal University,Nanjing 210013,China;College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]江苏第二师范学院地理科学学院,江苏南京210008 [2]太原理工大学水利科学与工程学院,山西太原030024 [3]中国科学院南京地理与湖泊研究所,江苏南京210008

出　　处：《中国环境科学》2023年第11期6079-6089,共11页China Environmental Science

基　　金：江苏第二师范学院引进人才科研启动项目(928201/030);中国科学院青年创新促进会项目(Y9CJH01001);山西省应用基础研究项目(201801D221052)。

摘　　要：在黄河流域生态保护和高质量发展战略背景下,探究沿黄湿地植物水分利用来源是揭示黄河湿地生态系统演替机制的重要基础.本文以汾河入黄典型河口湿地为研究区,分析旱季(5月)和雨季(9月)不同水源(降水、土壤水、地下水和河水)和优势植物的氢氧同位素特征,辨析湿地水分的补给来源和植物水分利用比例,探讨植物干湿季水分利用策略.结果发现,湿地地下水δ^(18)O、δD值同当地降水和汾河水相比明显贫化,地下水接受当地降水的有效补给仅在雨季,地下水主要来自黄河水侧渗并向汾河排泄.浅层土壤水(0~20cm)主要受降水补给,深层土壤水(20~80cm)则来自毛细地下水和汾河水补给.旱季,不同植物出现了水分利用的生态位分离现象,小型草本小香蒲(Typha minima,(46%±7%))和假苇拂子茅(Calamagrostis pseudophragmites,(95%±1%))对浅层土壤水利用率最高,大型草本水莎草(Juncellus serotinus)主要利用深层土壤水和地下水(89%±23%),而芦苇(Phragmites australis)主要利用河水、地下水和深层土壤水(86%±19%);雨季草本植物均主要利用深层土壤水、地下水和河水,表现出水分利用的生态位重叠.灌木柽柳(Tamarix chinensis)的水源存在季节转换,旱季均衡利用多种水源,雨季主要利用浅层土壤水(68%±5%).在未来暖干气候背景下,柽柳灵活的水分利用模式具有更大的生存优势,而草本植物间的水分竞争可能加剧.研究结果可加强对黄河中游湿地生态系统演变机制的认识,为湿地生态环境建设提供科学依据.Plant water source along the Yellow River is considered to be a foundation to reveal mechanisms of regional wetland evolution,due to the national strategy of ecological protection and high quality development of the Yellow River basin.This study investigated the characteristics of hydrogen and oxygen isotopes of rainfall,river water,groundwater,soil water and the xylem water for five dominant plants in the typical dry and rainy seasons during 2019,taking the Fen River estuary wetland as an example.The replenishment water sources of the Fen River wetland were explored using the relationship ofδ^(18)O andδD.The proportions of water uptake by different plants were further quantified using a direct inference method and the IsoSource mixing model.Results show that the isotope values of the wetland groundwater were much lower than those of rainfall and the Fen River.Wetland groundwater was rarely replenished by the local rainfall and mainly supplied by the Yellow River water.The shallow soil water at 0~20cm depth was mainly supplied by rainfall,while the deep soil water at 20~80cm depth was recharged by upward fluxes of groundwater and Fen River water.The proportions of plant water source were different among species.In the dry season,herbaceous plants showed niche separation of water use.The Typha minima and Calamagrostis pseudophragmites mainly used shallow soil water,while the Juncellus serotinus mainly used deep soil water and groundwater(89%±23%).The Phragmites australis mainly used the Fen River water,groundwater and deep soil water(86%±19%).However,all of the three herbaceous plants used deep soil water,groundwater and river water in the rainy season,demonstrating a niche overlap of the plant water use.Additionally,water sources of Tamarix chinensis exhibited a seasonal shift,characterizing by multiple sources in the dry season and shallow soil water(68%±5%)in the rainy season.Under future warm and dry climate conditions,T.chinensis is likely to exhibit distinctly survive advantages because of the strong pl

关 键 词：黄河中游 植物水分利用 水源补给 氢氧同位素 河口湿地 

分 类 号：X173[环境科学与工程—环境科学]