摘要
在干旱、半干旱区甚至海岸带区,水分是影响植物群落结构和功能的主要生态因子。开展海岸带植物水分利用策略研究,对阐明海岸带生态水过程和预测全球变化背景下的植物群落演替趋势是非常重要的。以黄河三角洲贝壳堤岛优势灌木——柽柳(Tamarix chinensis)为研究对象,以稳定同位素技术为主要研究手段,分析土壤水分、土壤盐分及潜在水源和柽柳木质部d18O值的变化;利用Iso Source软件,计算潜在水源对柽柳木质部水分的贡献率,探讨柽柳在不同水分条件下的水分利用策略。研究结果表明,在降水量充足的2013年7月20~22日,在柽柳吸收利用的水分中,有78.2%来自土壤水,包括30.3%的浅层(0~60 cm深度)土壤水和47.9%的深层(60~100 cm深度)土壤水,有21.8%来自浅层地下水;而在降水量偏少的2014年6月21~23日,土壤含水量显著降低,柽柳的主要水源由土壤水转变为浅层地下水,其对浅层地下水和土壤水的利用比例分别为79.1%和20.9%。生长在黄河三角洲贝壳堤岛海岸带的柽柳可以通过转换水分的主要来源,以适应水分胁迫,这种水分利用策略有利于增强柽柳在植物群落中的种间竞争力,提高植物群落水资源的利用效率,为更好的阐述植物群落内的水分调节和分配机制提供理论基础。
Water is very important ecological factor for the structure and function of plant communities in arid and semiarid regions, including coastal zones. Determination of water use patterns of plants in the coastal zones is critical to our understanding of local eco-hydrological processes and predicting the trends in the ecological succession under global climate change. To determine the water use patterns of Tamarix chinensis under different water conditions of Shell Islands in the Yellow River Delta, we analyzed the moisture and salinity in soils and d18 O values of different potential water sources and the water in the xylem of Tamarix chinensis.The Iso Source model was employed to estimate the contributions of potential water sources to the water in the xylem of Tamarix chinensis. On July 20-22, 2013, there was abundant precipitation, 78.2% of the water used by Tamarix chinensis was from the water in the soil(30.3% from the shallow soil(0-60 cm depth) and 47.9%from deep soil(60-100 cm depth). On June 21-23, 2014, there was less precipitation, the main water source of Tamarix chinensis shifted from the water in the soil to shallow groundwater as the water in the soil decreased significantly. Specifically, Tamarix chinensis obtained the water of 79.1% and 20.9% from shallow groundwater and the water in the soil, respectively, under these conditions. Tamarix chinensis in the Shell Islands in the Yellow River Delta could improve its drought resistance by shifting its main water sources, resulting in competitive and increased water use efficiency.
出处
《湿地科学》
CSCD
北大核心
2015年第6期765-771,共7页
Wetland Science
基金
国家自然科学基金项目(41201023和41401100)
山东省自然科学基金省属高校优秀青年人才联合基金项目(ZR2015JL014)资助
关键词
柽柳
水分利用策略
氧稳定同位素
贝壳堤岛
黄河三角洲
Tamarix chinensis
water use patterns
oxygen stable isotope
Shell Island
the Yellow River Delta
