红砂植物种群空间分布与沙子粒级及地貌起伏之间的关系

The Relationship between the Spatial Distribution of the Reaumuria soongorica and Sand Grain Size and Topography

红砂(Reaumuria soongorica)植物种群是草原化荒漠和典型荒漠区重要建群种或优势种之一,是防风固沙的重要物种。为探讨巴丹吉林沙漠东缘红砂种群空间分布特征及其与沙子粒级及地貌起伏的关系,掌握红砂种群自然分布状态及其影响因素,为防风固沙以及荒漠区植被保护提供理论指导。依托阿拉善右旗塔木素苏木地区“塔木素野生肉苁蓉及梭梭产籽基地”展开研究,采用大样地(192 hm2)机械取样法,结合地统计分析和典型相关分析等研究方法,得到初步结论如下,(1)红砂植物种群的密度、高度和冠幅空间异质性处于中等强度(结构比在25%-75%),斑块尺度依次增大,分别为931、1554、2213 m。(2)中沙斑块尺度较小,仅为121 m;粗沙斑块尺度是细沙的6倍多,分别为1499 m和246 m,二者空间异质程度高于中沙。(3)红砂植物种群密度空间分布与细沙空间分布紧密相关(P<0.050),且高密度分布区与高比例细沙分布区重合;受红砂植物学特征和生物学特性影响,红砂在定植前后对环境的要求不同。(4)该研究区域风向作用形成现有地貌起伏特征,地貌起伏特征与风向共同作用决定沙子粒级空间分布特点,进而与红砂植物种群生物学特征相互作用形成其空间分布现状。

Reaumuria soongorica is one of the important constructive or dominant species in steppe deserts and typical desert areas,and an important species for windproof and sand fixation.To explore the spatial distribution characteristics of R.soongorica population on eastern margin of the Badain Jaran Desert and its relationship with sand fraction and terrain fluctuations,to grasp the natural distribution status of R.soongorica population and its influencing factors,and to provide theoretical guidance for windproof,sand fixation and desert vegetation protection,the research was carried out based on the“Tamusu Wild Cistanche and Haloxylon Seed Production Base”in the Tamusu Sumu area of Alxa Right Banner,using a large sample plot(192 hm2)mechanical sampling method,combined with research methods such as geostatistical analysis and canonical correlation analysis.We found that,(1)The density,height and canopy spatial heterogeneity of R.soongorica were at medium intensity(the structure ratio was 25%‒75%),and the patch size increased successively to 931 m,1554 m and 2213 m,respectively.(2)The patch size of the middle sand was small,only 121 m;the patch size of the coarse sand was more than 6 times that of the fine sand,1499 m and 246 m,respectively.They spatial heterogeneity was higher than that of the middle sand.(3)The spatial distribution of R.soongorica’density was closely related to the fine sand spatial distribution(P<0.050),and the high-density distribution area overlaped with the high-proportion fine sand distribution area;R.soongorica had different requirements for the environment before and after planting due to the botanical and biological characteristics.And(4)the wind direction in the study area formed the current landform fluctuation characteristics.The combination of the landform fluctuation characteristics and the wind direction determines the spatial distribution characteristics of sand size,and then interacted with the biological characteristics of R.soongorica to form its spatial distribution status.