扎龙盐沼湿地旱化特征及其对演替的影响

Effect of Drought Stress on Succession of the Zhalong Wetland

结合降水量、湿地蓄水量以及水面面积数据,研究扎龙盐沼湿地近年来的旱化特征及其对湿地演替的影响。结果表明：近年来,扎龙湿地呈现出持续干旱的状态是多种要素综合作用的结果。1970年以前,研究区的旱涝情况主要受自然环境的影响（降水量的年际变化、厄尔尼诺事件以及太阳黑子周期性变化等）;1970年以后,湿地的旱涝程度是自然环境与人为活动共同作用的。1860—1970年,扎龙湿地旱涝变化以3-6 a和20-30 a周期为主。近半个世纪以来,扎龙湿地表现出干旱缺水的状态,其原因主要与人类活动限制了乌裕尔河上游径流进入湿地有关。扎龙湿地持续干旱缺水,导致大面积沼泽消失并形成盐渍化土壤,研究区盐渍土面积已经由1979年的170 km2增加到2017年的245 km2,并且有相当一部分土壤盐渍化过程发生在湿地核心区。

In this study,the effect of drought stress on the succession of the Zhalong Wetland in northeast China in recent years was analyzed based on the data of precipitation,water storage and water area the study area. The results indicated that the persistent drought was jointly affected by various factors. The rought or looding in the wetland was influenced by the natural factors before 1970,such as the fluctuation of runoff volume,EI Nino event and change of solar spots,nevertheless,it was jointly governed by both the natural environment change and human activities after then. During the period from 1860 to 1970,there were the 3-6 a and 20-30 a main periods of drought or flooding fluctuation. However,drought was dominant in recent 50 years due to the increase of human activities.The persistent drought stress resulted in the disappearance of wetland and soil salinization in large area,that is,the area of salinized soil was enlarged from 170 km2 in 1979 to 245 km2 in 2017,and some of which occurred in the core area of the Zhalong Wetland.