古尔班通古特沙漠沙丘主要灌木的种群数量动态

种群数量动态的研究是认识种群的生存现状及发展动态的前提。通过对古尔班通古特沙漠固定沙丘、半固定沙丘和流动沙丘上主要固沙灌木的样地调查，分析了固沙灌木的年龄结构，建立了3种沙丘上固沙灌木的静态生命表和存活曲线。结果表明：（1）固沙灌木的存活个体数呈逐级递减的趋势，幼龄个体占有很高的比例；固定沙丘上梭梭（Haloxylon ammodendron）呈现Ⅰ型存活曲线，种群退化，白梭梭（Haloxylon persicum）呈现Ⅱ型存活曲线，种群稳定；（2）半固定沙丘上白梭梭呈Ⅱ型存活曲线，种群相对稳定；沙拐枣（Calligonum mongolicum）和油蒿（Artemisia ordosica）均呈现Ⅰ型存活曲线，种群处于退化状态；（3）流动沙丘上沙拐枣呈现Ⅲ型存活曲线，种群有较大的增长潜力，白梭梭呈现出Ⅱ型存活曲线，种群相对稳定，油蒿呈现出Ⅰ型存活曲线，种群处于不稳定的退化状态。

Population dynamics of main sand-fixing shrubs in the Gurbantunggut Desert

The study of population dynamics is a prerequisite for understanding the current situation of population survival and development dynamics. In this paper,the age structure of sand-fixing shrubs was analyzed and the static life table and survival curve were established based on our survey of the sand-fixing shrubs under three types of sand dunes(i.e. the fixed sand dunes,the semi-fixed sand dunes and the mobile sand dunes)in the Gurbantunggut Desert. We developed the following conclusions:(1)The survival number of sand-fixing shrubs showed a gradual decrease with age-class and high proportion of sand-fixing shrubs population is young individuals in three habitats.(2)On fixed sand dunes:the population survival curves of Haloxylon ammoolenelron was close to Deevey-Ⅰ type which indicated that its population was degonerating;Haloxylon persicum population was close to Deevey-Ⅱ type survival curve,the population was in a dynamic and stable state.(3)On semi-fixed sand dunes:H.persicum belong to Deevey-Ⅱ type survival curve,its population in a relatively stable state;Calligonum mongolicum and Artemesia ordosica all belong to Deevey-Ⅰ type survival curve,which shows that these populations were in a degraded state.(4)On mobile sand dunes:C. mongolicum population presented Deevey-Ⅲtype survival curve,which had great growth potential;H.persicum population presented Deevey-Ⅱ type survival curve,which shows that the population was in a relatively stable state;A.ordosica population presented Deevey-Ⅰ type survival curve,which indicates that the populations was in unstable state of degradation.