论文部分内容阅读
以黄河三角洲海岸带贝壳堤湿地灌木群落主要建群种柽柳为对象,利用稳定同位素技术测定柽柳木质部和潜在水源δ~(18)O值的时空变化,采用IsoSource模型计算潜在水源对柽柳的贡献比例,研究海岸带不同生境中柽柳对不同水分条件的适应机制.结果表明:在降水较少的干旱年份,相对于不稳定的降水,柽柳倾向于利用稳定的土壤水和浅层地下水,但是在不同微地形生境下柽柳的水分利用策略有所差异.滩脊的柽柳72.6%~95.4%水分来源于浅层地下水和含水量相对较高的深层土壤水(40~100 cm);高潮线附近的柽柳有40.7%~97.3%的水分来源于上层土壤水(0~40 cm),以避免海水和浅层地下水的盐分胁迫.柽柳对外界水盐条件变化具有较强的适应性,在海岸带可利用水资源缺乏的恶劣生境中具有更强的种间竞争优势,从而导致柽柳单优灌木群落的形成.
Taking the Tamarix asparagus, the main shrub community of shrubbery in the coastal wetlands of the Yellow River Delta, the δ 18 O values of the xylem and potential water sources of Tamarix spp. Were determined by using stable isotope techniques. The contribution of potential water sources to tamarix was calculated using the IsoSource model , And studied the adaptation mechanism of Tamarix elongata to different water conditions in different habitats of the coast.The results showed that Tamarix tended to make use of stable soil water and shallow groundwater in arid years with less precipitation, The water use strategies of Tamarix chinensis under micro-topography varied slightly from 72.6% to 95.4% of the tidal flat in the ridge of the tundra from shallow groundwater and deep soil water (40-100 cm) with relatively high water content. Tamarisk 40.7% -97.3% of the water comes from the upper soil water (0-40 cm) to avoid the salt stress of seawater and shallow groundwater.The tamarisk has strong adaptability to the change of water and salt conditions in the outside world and is available in the coastal zone Harsh water scarcity has a stronger interspecific competitive advantage in Habitat, resulting in the formation of the single dominant shrub community in Tamarix.