| 引用本文: | 许秀丽,李云良,谭志强,张奇.鄱阳湖湿地典型植被群落地下水—土壤—植被—大气系统界面水分通量及水源组成.湖泊科学,2018,30(5):1351-1367. DOI:10.18307/2018.0517 |
| XU Xiuli,LI Yunliang,TAN Zhiqiang,ZHANG Qi.Water fluxes in the groundwater-soil-plant-atmosphere continuum and water sources of typical wetland vegetation communities in Poyang Lake. J. Lake Sci.2018,30(5):1351-1367. DOI:10.18307/2018.0517 |
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| 摘要: |
| 地下水-土壤-植被-大气系统（GSPAC）界面水分传输是湿地生态水文过程研究的关键.本文选取鄱阳湖湿地高位滩地的2种典型植被群落：茵陈蒿（Artemisia capillaris）和芦苇（Phragmites australis）群落为研究对象，运用HYDRUS-1D垂向一维数值模拟，量化了湿地GSPAC系统界面水分通量，阐明了典型丰水年（2012年）和枯水年（2013年）鄱阳湖湿地植被群落的蒸腾用水规律和水源组成.结果表明：（1）茵陈蒿和芦苇群落土壤大气界面的年降水入渗量为1570~1600 mm，主要集中在雨季4-6月，占年总量的60%；植物大气界面的年蒸腾总量分别为346~470 mm和926~1057 mm，其中7-8月植被生长旺季最大，占年总量的40%~46%；地下水根区土壤界面的向上补给水量受不同水文年水位变化的影响显著，地下水年补给量分别为15~513 mm和277~616 mm，主要发生在蒸散发作用强烈和地下水埋深较浅的时段.（2）植被蒸腾用水分为生长初期（4-6月）和生长旺季（7-10月）2个阶段，丰水年植被的整个生长期蒸腾用水充足，枯水年植被生长旺季的蒸腾用水受到严重水分胁迫，实际蒸腾量仅为潜在蒸腾量的一半左右.（3）不同水文年湿地植被生长旺季的水源贡献不同：丰水年茵陈蒿群落以地下水补给为主，芦苇群落以湖水和地下水补给为主；枯水年茵陈蒿群落以降水和前期土壤水储量为主，芦苇群落以地下水补给为主.本研究结果有助于揭示湿地植被的水分利用策略，为阐明湖泊水情变化与植被演替的作用机理提供参考依据. |
| 关键词: 水分通量 水源组成 植被水分胁迫 鄱阳湖湿地 HYDRUS-1D模型 茵陈蒿 芦苇 |
| DOI：10.18307/2018.0517 |
| 分类号: |
| 基金项目:国家自然科学基金项目（41601031，41771037，41401031）和江苏省自然科学基金项目（BK20141061）联合资助. |
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| Water fluxes in the groundwater-soil-plant-atmosphere continuum and water sources of typical wetland vegetation communities in Poyang Lake |
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XU Xiuli1, LI Yunliang2, TAN Zhiqiang2, ZHANG Qi2
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1.College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China;2.Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
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| Abstract: |
| Water movement within the groundwater-soil-plant-atmosphere continuum (GSPAC) is the key to wetland eco-hydrological process research. In this paper, two typical wetland vegetation communities, the Artemisia capillaris and Phragmites australis communities were selected as study objects in Poyang Lake wetland. The HYDRUS-1D model was used to explore the GSPAC water fluxes in the two wetland vegetation communities. Besides, the vegetation transpiration and water sources of the two typical vegetation communities were clarified and compared for high (2012) and low (2013) water table years. The results showed that:(1) The annual rainfall infiltration flux at soil-atmosphere interface amounted to 1570-1600 mm, with 60% falling in the rainy season from April to June. The annual transpiration at plant-atmosphere interface totalled 346-470 mm and 926-1057 mm, respectively, for the A. capillaris and P. australis communities, with the highest values from July to August taking up 40%-46% of the annual amounts. The groundwater upward fluxes to rootzone were significantly influenced by the water table variation in different hydrological years. The annual amounts of groundwater recharge were 15-513 mm and 277-616 mm, respectively for the two vegetation communities, which concentrated in the periods with high water table and evapotranspiration rate. (2) The process of vegetation transpiration were divided into two different stages:the initial (April-June) and the main (July-October) growth stage. In the high water table year, vegetation transpiration water used in the whole growth stage can be satisfied. In the low water table year, vegetation suffered severe water stress in the main growth stage, and the actual transpiration decreased to approximately half of the potential ones. (3) The supplying water sources of vegetation communities in main growth stage were different between the high and low water table years. In the high water table year, groundwater recharge was the major water source of the A. capillaris community, while groundwater and lake water were the major water sources of P. australis community. However, in the low water table year, rainfall infiltration and antecedent soil water storage become the major water sources of the A. capillaris community, and groundwater was the major water source of P. australis community. These results help to reveal the vegetation water utilization strategy and better understand the interaction mechanism of vegetation succession to hydrological changes in wetland. |
| Key words: Water fluxes supplying water sources vegetation water stress Poyang Lake wetland HYDRUS-1D model Artemisia capillaris Phragmites australis |
