地理学报 ›› 2004, Vol. 59 ›› Issue (1): 33-39.doi: 10.11821/xb200401004

• 地表通量监测 • 上一篇    下一篇

盐生荒漠地表水、热与CO2输送 的实验研究

李彦1, 王勤学2, 马健1, 渡边正孝2, 张小雷1   

  1. 1. 中国科学院新疆生态与地理研究所阜康荒漠生态站,乌鲁木齐 830011;
    2. 日本国立环境研究所,筑波305-8506
  • 收稿日期:2003-09-25 修回日期:2003-11-22 出版日期:2004-01-25 发布日期:2004-01-25
  • 作者简介:李彦 (1963- ), 男, 博士, 研究员, 中国科学院“百人计划”入选者。目前主要从事干旱区地植物学与植物水分关系研究。E-mail:liyan@ms.xjb.ac.cn
  • 基金资助:

    亚洲太平洋地区环境创新战略项目(APEIS) 环境综合监侧子课题(IEM),中国科学院知识创新工程项目 (KZCX3-SW-326)

Water, Heat and CO2 Transfer over a Salinized Desert in the Arid Area

LI Yan1, WANG Qinxue2, MA Jian1, WATANABE Masataka2, ZHANG Xiaolei1   

  1. 1. Fukang Station of Desert Ecology, Xinjiang Institute of Ecology and Geography, CAS, Urumqi 830011, China;
    2. National Institute for Environmental Studies, Tsukuba 305-8506, Japan
  • Received:2003-09-25 Revised:2003-11-22 Online:2004-01-25 Published:2004-01-25
  • Supported by:

    Integrated Environmental Monitoring Subproject, the Asia-Pacific Environmental Innovation Strategy Project; Knowledge Innovation Project of CAS, No.KZCX3-SW-326

摘要:

利用安装在准噶尔盆地南缘多汁盐柴类荒漠上的涡度相关系统与配套的微气象观测系统所得数据,分析了显热、潜热与CO2通量的日过程和季节变化特点及各通量间的相互关系。数据显示了一个明显违背植物水分关系一般规律的现象:当水汽 (潜热) 通量明确显示土壤水分亏缺时,净光合 (CO2通量) 却未受到影响。因此推测当地原生植物的根系在积盐严重的土壤上层没有发育,所以其水分状况与光合能力不受上层土壤干湿的影响,观测到的水汽通量的变化主要由土壤蒸发的变化造成的。

关键词: 荒漠;显热通量;潜热通量;净光合;潜水位;准噶尔

Abstract:

An eddy-covariance system and a micrometeorological station were installed at south periphery of Gurbantonggut Desert in April of 2002. Evaluation of the data showed that the measurements of sensible heat (H), latent heat (LE) and CO2 fluxes were reliable. However, a special phenomenon was revealed from detailed analysis on the diurnal and seasonal changes of the fluxes: when LE fluxes signified a strong water shortage and hence severe water stress should have been applied on the plants, CO2 fluxes indicated that the photosynthesis of the plant community was not affected. This was obviously against generally-accepted theory on plant-water relations. No concrete evidence available so far can explain this phenomenon, but we may speculate that local shrub plant might not benefit from the rainfall. Being a salinized desert, its upper soil layer contains high salt content. Thus shrub roots could not develop and survive at upper layer of the soil. On the contrary, roots might develop mainly at deep soil layers near the groundwater table. Therefore, whether rainfall wetted the upper soil layer or not, plant water condition was not affected, but the evapotranspiration (LE) was. The measured change of LE fluxes mainly came from evaporation of soil surface and CO2 fluxes were mainly determined by plant photosynthesis. Since the former is mainly influenced by soil water condition near soil surface and the latter determined by soil water condition near the groundwater table, it is just reasonable that the two aspects are not correlated. Thus, the phenomena reported here occurred under the combined local climatic, botanical and soil conditions and it is not really against the principle of plant-water relations in general.

Key words: desert, sensible heat, latent heat, net photosynthesis, groundwater table, Junggar