干旱区生态环境知识资源中心(Arid): 基于deltaD和delta~(18)O的青海湖流域芨芨草水分利用来源变化研究

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	基于deltaD和delta~(18)O的青海湖流域芨芨草水分利用来源变化研究
其他题名	Variations in water use for Achnatherum splendens in Lake Qinghai watershed, based on deltaD and delta~(18)O
	吴华武; 李小雁; 蒋志云; 李静; 郑肖然; 赵殿智
来源期刊	生态学报
ISSN	1000-0933
出版年	2015
卷号	35 期号:24 页码:8174-8183
中文摘要	水分条件是限制干旱半干旱地区植物生长重要的生态因子,为了揭示青海湖流域典型生态系统下芨芨草植物的水分利用来源及其如何响应水分条件的变化,选择了自然和干旱控制条件下芨芨草植物,通过测定芨芨草植物茎水和各潜在水源(土壤水、地下水及降水)中deltaD、delta~(18)O组成,并利用直接比较分析法和多源混合模型计算芨芨草植物对土壤水的利用比例。研究结果表明:表层土壤水分和土壤水中deltaD、delta~(18)O值表征出较大波动范围,其直接受降水和蒸发作用影响,土壤蒸发线的斜率和截距明显小于大气水线斜率和截距,表明土壤水中同位素组成经历了强烈的蒸发分馏过程,而芨芨草茎水中deltaD、delta~(18)O值都集中分布土壤水蒸发线附近,说明芨芨草根系主要利用不同深度的土壤水。自然条件下芨芨草在生长季初期(6月)利用表层土壤水(010cm,45.1%),8-9月份大降水事件影响土壤含水量和同位素组成,降水入渗深度较深且芨芨草根系对土壤水分吸收的比例相差不大,表明根系在土壤含水量较高时均能吸水不同深度土壤水。在干旱控制条件下芨芨草在7月初主要利用表层土壤水(0-30cm),随着表层土壤水分的减少,根系吸收深度转向较深土壤层,而灌溉后表层土壤水分明显增加,其吸收深度又转向表层,表明芨芨草根系吸收深度能敏感地响应土壤水分的变化。另外还发现芨芨草在生长季内并未直接利用地下水。
英文摘要	Water availability is a key ecological factor for plant growth in arid and semi-arid regions. We identified the characteristics of water-uptake patterns by Achnatherum splendens and how it responds to changes in water conditions in typical steppe ecosystem (Lake Qinghai watershed). We analyzed stable isotopes of plant stem water and potential water sources including soil water, groundwater, and precipitation via direct comparison with differences among potential water sources and a multi-source mixing model calculating the plant-use proportions from diverse soil depths under natural and drought treatment areas. The results showed that there were large fluctuations in the soil moisture and the isotopic contents(deltaD) of soil water in the surface soil layers, directly influenced by precipitation and evaporation. The slope and intercept of the evaporative soil water line were evidently smaller than those of the meteoric water line, indicating that the isotopic contents from soil water experienced stronger evaporation fractionation processes. The isotopic contents (deltaD and delta~(18)O) of the stem were scattered along the soil evaporative water line indicating that the possible water sources were extracted from diverse soil water depths. A. splendens absorbed mainly surface soil water (the proportion from 0-10cm was 45.1% in June) at the early growth stage. Large precipitation events significantly affected the soil water content and isotopic contents and infiltrated into deep soil layers. Differences in plant water use proportions were minimal during August and September, which revealed that the roots of A. splendens extracted water from various depths when soil water availability was high. Under the drought treatment conditions,A. splendens used mostly surface soil water (0-30 cm) in early July. The absorption water depth shifted to deep soil layers when the surface soil water became drier. However,the absorption depth again shifted from deep to surface soil layers when surface soil moisture sharply increased after irrigation. Groundwater was not a main water source for A. splendens during the entire growing season.
中文关键词	氢氧稳定同位素 ; 降水 ; 土壤水 ; 芨芨草 ; 水分利用来源 ; 青海湖流域
英文关键词	stable isotopes precipitation soil water Achnatherum splendens water-use sources Lake Qinghai watershed
类型	Article
语种	中文
国家	中国
收录类别	CSCD
WOS类目	Life Sciences & Biomedicine - Other Topics
WOS研究方向	Life Sciences & Biomedicine - Other Topics
CSCD记录号	CSCD:5591418
来源机构	中国科学院地理科学与资源研究所 ; 北京师范大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/233219
作者单位	吴华武, 北京师范大学资源学院, 北京 100875, 中国.; 李小雁, 北京师范大学资源学院, 北京 100875, 中国.; 蒋志云, 北京师范大学资源学院, 北京 100875, 中国.; 郑肖然, 北京师范大学资源学院, 北京 100875, 中国.; 李静, 中国科学院地理科学与资源研究所, 北京 100101, 中国.; 赵殿智, 青海省三角城种羊场, 刚察, 812300.
推荐引用方式 GB/T 7714	吴华武,李小雁,蒋志云,等. 基于deltaD和delta~(18)O的青海湖流域芨芨草水分利用来源变化研究[J]. 中国科学院地理科学与资源研究所, 北京师范大学,2015,35(24):8174-8183.
APA	吴华武,李小雁,蒋志云,李静,郑肖然,&赵殿智.(2015).基于deltaD和delta~(18)O的青海湖流域芨芨草水分利用来源变化研究.生态学报,35(24),8174-8183.
MLA	吴华武,et al."基于deltaD和delta~(18)O的青海湖流域芨芨草水分利用来源变化研究".生态学报 35.24(2015):8174-8183.