民勤绿洲荒漠过渡带梭梭种群的数量动态及分布格局研究

Study on the Quantitative Dynamics and Distribution Patterns of Haloxylon ammodendron Population in the Transition Zone of Minqin Oasis and Desert

为了解民勤绿洲荒漠过渡带梭梭种群的数量动态特征与分布格局,采用样地调查法与数据分析法相结合的方式,于2023年5月1-15日,开展了实地调研。并用梭梭种群年龄结构与静态生命表,揭示了种群数量动态特征,用6种常用聚集度指标,判断了梭梭种群在过渡带不同区域分布格局的变化规律。结果表明:①民勤绿洲荒漠过渡带梭梭种群以中幼林为主体,属于增长型种群;②种群存活曲线属于Deevey-Ⅲ型凹曲线,说明梭梭幼树死亡率较高,但随着树龄增长,死亡率逐渐减小;③梭梭种群分布呈聚集分布态势,由绿洲边缘向沙漠边缘延伸,种群分布格局无明显变化规律。

In order to understand the dynamic characteristics and distribution patterns of the population of Haloxylon ammodendron in the transitional zone of Minqin oasis and desert,this paper conducted a field survey on May 1-31,2023,by using a combination of sample plot survey and data analysis methods.And the age structure and static life table of the shuttle population are used to reveal the dynamic characteristics of population quantity.Six commonly used aggregation indicators are used to determine the changes in the distribution patterns of the shuttle population in different regions and age classes of the transitional zone.The results indicate that:firstly,the population of Haloxylon ammodendron in the transitional zone of Minqin oasis and desert is mainly composed of young and middle-aged forests,belonging to a growth type population.Secondly,the population survival curve belongs to the Deevey-Ⅲconcave curve,indicating that the mortality rate of young Haloxylon ammodendron trees is relatively high,but gradually decreases with age.Thirdly,the distribution of the Haloxylon ammodendron population shows a clustered distribution trend,extending from the edge of the oasis to the edge of the desert.The population distribution pattern has no obvious change patterns.As the age class increases,the population distribution pattern also shifts from clustered distribution trend to uniform distribution,and there is also a small amount of random distribution during this period.