【作者】 贾亚敏；

【导师】 刘彤；

【作者基本信息】 石河子大学 ， 植物学， 2007， 硕士

【摘要】 种群空间分布格局是种群生物学特性对环境条件长期适应和选择的结果,对于了解种群特征、种内和种间关系以及种群与环境关系有特殊意义。莫索湾南缘沙漠是古尔班通古特沙漠南向延伸的支脉,该沙漠的植被稳定对于周边县市的生态环境有重要影响。为此我们对研究区的植被分布及优势灌木的分布格局研究作了研究,旨在揭示物种之间,物种与环境之间相互作用的生态过程,对于荒漠区植被的保护和恢复提供理论依据,在此基础上开发利用优质牧草心叶驼绒藜。所得结论如下:(1)采用半方差分析法对该区重要值较大的4种灌木进行格局分析:心叶驼绒藜、梭梭、琵琶柴种群在3个样地均为不同程度的聚集分布,这与植物本身固有的生长特性、繁殖和扩散的空间范围受到恶劣环境的限制有关,种群的扩散总是以母体为中心展开的聚集分布;白皮沙拐枣种群为零星的随机分布。(2)采用点格局Ripley’s K(d)函数分析发现:3个样地的心叶驼绒藜格局变化复杂,并在不同尺度发生格局类型的变化;梭梭、琵琶柴和白皮沙拐枣种群以聚集分布为主。种间关联分析发现,心叶驼绒藜和梭梭种群基本没有种间关联,只在第3样地,即沙漠腹地的样地,在0~50m范围有较弱的种间负关联;心叶驼绒藜和琵琶柴有共同的生境,所以种间关联关系复杂,既有正关联关系,也有负关联关系,表明种间关系更多地受到环境的影响。梭梭和琵琶柴种群基本没有种间关联关系。(3)对心叶驼绒藜种群分布格局的环境依赖研究发现:心叶驼绒藜种群主要分布于沙丘底的草原化荒漠和沙丘坡,该处有较高的土壤含水量和有机质含量,但pH值和电导率也较高,梭梭主要分布在沙丘顶部,琵琶柴种群主要分布在沙丘的低洼区,该区土壤有极高的pH值和电导率。得出坡形、坡位等导致的水等环境差异是影响物种分布的关键因素,而物种间相互作用关系较弱。(4)对心叶驼绒藜种群更新格局研究发现:3个样地心叶驼绒藜大小株的分布格局类似,以集群分布为主,与物种本身的种子散布机制有关。从绿洲荒漠过渡带到沙漠腹地,更新苗数量增加,反映了心叶驼绒藜种群的增长趋势和对沙漠环境的适应性。基于本研究发现的聚集分布格局以及对沙丘底和沙丘坡的依赖,建议在恢复和保护绿洲荒漠植被时,可将心叶驼绒藜与梭梭种群合理配置用于沙丘坡和沙丘顶的植被恢复,与琵琶柴种群合理配置用于沙丘底和沙丘坡植被恢复,各自集群分布后搭配建植,充分发挥植被的生态防护功能,进而合理开发利用这一牧草资源。更多还原

【Abstract】 Population spatial distribution pattern is the result of long adaptation and selection between the biological characteristics and environment, it can be used to analyze the relationships on the trait of population, interspecific and intraspecific connection, and population and environment. The southern edge of Mosuowan desert is a southern branch of Guerbantonggute desert. The vegetation stabilization of the district affect the ecological environment of neighbouring cities. So we studied the vegetation distribution and distribution pattern of dominance shrub, we aimed to discover the interaction of species and environment, and provided the theoretics base to the protection and recovery, then we can explore and develop the grazing-Ceratoides ewersmanniana. The results as following:(1)Appling the semi-variance analysis and choosing 4 kinds of shrubs of higher important values, the results of pattern indicated: Ceratoides ewersmanniana, Haloxylon ammodendron, Reaumuria soongorica belonged to cluster distribution pattern in different degree in three plots, these might have something with the growth characteristics, propagation and diffusion of the plant itself, and meanwhile, these properties might limited by the severe environment, so the seed diffusion relied on the matrix, and in the center of matrix; Colligonum leucocladwn(Schrenk Bge) belonged to random distribution in scatter.(2)Appling the Ripley’s K(d) function of point pattern, the result showed: the patterns of Ceratoides ewersmanniana had varied in different scale, and the variation were different in the three plots; Haloxylon ammodendron, Reaumuria soongorica, Colligonum leucocladwn were mainly cluster distribution in three plots. The result of interspecies association analysis found: there were no interspecies association between Ceratoides ewersmanniana and Haloxylon ammodendron in 1and 2 plot, only in 3 plot, which is in the sand hinterland, there were weak association from 0 to 50 meter. There were complex relationship between Ceratoides ewersmanniana and Reaumuria soongorica for the reason of their same habitat, showing positive and minus association in three plots.(3)According to the analysis of distribution and environment about Ceratoides ewersmanniana, it mainly distributed on the desert steppe of sand bottom and sand dune, which had higher water content and organic matter, and higher pH and conduction ratio; Haloxylon ammodendron distributed on the sand top; Reaumuria soongorica mainly distributed on the low-lying of sand bottom, which had the highest pH and conduction ratio. We found the key factors affected species distribution were the shape and position of slope, the weak interaction of species was secondary in all factors.(4)We found the similar pattern of big and young plants of Ceratoides ewersmanniana in three plots, which belonged to cluster pattern, and had connection with the mechanism of seed diffusion. From the transitional oasis zone to the hinterland in the sand, there were increased numbers of regeneration seedlings, which might reflect the increased trend and well adaptation to the sand habitat.Based on the result of relationships between pattern and environment, we proposed some measure to protect the desert vegetation, we can match Ceratoides ewersmanniana and Haloxylon ammodendron in the sand dune and top, match Ceratoides ewersmanniana and Reaumuria soongorica in the sand bottom and dune, on the base of cluster pattern of one’s own, then we can make use of the ecological function of vegetation, and develop the good grazing further and scientifically.更多还原