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近年来,鄱阳湖水位持续走低,极端干旱事件频繁发生,湿地生态系统结构与功能遭受破坏。为此,于2014年鄱阳湖湿地保护区两个断面分层采集0~100 cm土壤,并采集优势种植物和河湖水以及地下水数据,运用稳定同位素技术,分析了土壤-植物-河湖水-地下水稳定同位素变化特征,并探寻它们之间的补给关系。结果表明,两断面土壤水氧同位素变化范围分别为–10.48‰~–5.23‰和–12.39‰~–6.55‰,算术平均值分别为–8.36‰和–8.63‰。断面一表层(0~30 cm)土壤水氧重同位素较富集,且随深度增加而减小;断面二表层(0~40 cm)土壤水中氧同位素组成基本无变化。断面一的地下水主要是受降水补给,断面二可能是受降水和河湖水共同补给。鄱阳湖湿地两断面优势种植物虉草叶片水的氧同位素值最大,为–0.9‰,其次是灰化苔草和芦苇,分别为–4.23‰和–5.25‰。
In recent years, Poyang Lake water level continues to decline, extreme drought events occur frequently, wetland ecosystem structure and function suffered damage. Therefore, 0-100 cm soil layers were collected in two sections of Poyang Lake Wetland Reserve in 2014, and the dominant species, river, lake and groundwater data were collected and the stable isotope techniques were used to analyze the effects of soil-plant-lake-groundwater Stable isotope variation characteristics, and explore the supply relationship between them. The results showed that the ranges of water and oxygen isotope variation in the two sections were -10.48 ‰ -5.23 ‰ and -12.39 ‰ -6.55 ‰ respectively, and the arithmetic mean values were -8.36 ‰ and -8.63 ‰, respectively. Oxygen and heavy isotopes of water in the surface (0 ~ 30 cm) section of the section are enriched, and decrease with depth; the oxygen isotope composition of soil water in section 0 (0 ~ 40 cm) does not change. Groundwater in section 1 is mainly recharged by precipitation. Section 2 may be recharged by precipitation and rivers and lakes. Poyang Lake wetland dominant species Xerophytia leaves water oxygen isotope value of the largest, -0.9 ‰, followed by ashes Carex and reed, respectively -4.23 ‰ and -5.25 ‰.