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不同生境条件下沙冬青种群分布格局与特征的初步研究
引用本文:尉秋实,王继和,李昌龙,庄光辉,陈善科.不同生境条件下沙冬青种群分布格局与特征的初步研究[J].植物生态学报,2005,29(4):591-598.
作者姓名:尉秋实  王继和  李昌龙  庄光辉  陈善科
作者单位:1 甘肃省治沙研究所,武威 733000
2 内蒙古阿拉善盟草原站,左旗 750300
摘    要:对阿拉善荒漠区不同生境出现的3种沙冬青(Ammopiptanthus mongolicus)种群的生态格局、密度特征、形态格局和动态特征进行了对比研究。结果表明:1)沙冬青种群因生境异质性而形成了各自的生态格局。在流动和半固定风沙地上,种群呈均匀分布,在半固定及砾质沙地、冲积洪积坡地和古河床上,种群呈集群分布。2)单株生长状况因种群密度和区域环境特点而形成了不同的形态格局。种群密度按流动沙地→半固定沙地和砾质沙地交错带→冲积洪积砾质坡地的次序依次减小,不同生境条件下种群密度与个体高度、幅度间、个体高度与幅度间的相关性不同。3)种群年龄结构因生境异质性形成了各自的年龄格局。在流动沙地上,种群内中、老龄个体数分布较均匀,但缺少幼龄个体,种群走向老龄化。半固定和砾质沙地交错带的种群内不但幼龄个体极少,而且种群内不同龄级个体数的分布不均匀,种群趋于衰退。砾质坡地上的种群内不同高度级和幅度级的个体数分布极不均匀,种群严重退化。4)3种生境中以沙冬青为优势种组成单优群落,种群内均出现严重断代现象,表现为老龄个体多,幼龄、中龄个体极少,种群缺乏后备资源的势态。

关 键 词:种群生态  沙冬青  分布格局  濒危植物  
收稿时间:2004-05-08
修稿时间:2004年5月8日

A PRELIMINARY STUDY ON THE DISTRIBUTION PATTERNS AND CHARACERISTICS OF AMMOPIPTANTHUS MONGOLICUS POPULATIONS IN DIFFERENT DESERT ENVIRONMENTS
YU Oiu-Shi,WANG Ji-he,LI Chang-long,ZHUANG Guang-hui,CHEN Shan-ke.A PRELIMINARY STUDY ON THE DISTRIBUTION PATTERNS AND CHARACERISTICS OF AMMOPIPTANTHUS MONGOLICUS POPULATIONS IN DIFFERENT DESERT ENVIRONMENTS[J].Acta Phytoecologica Sinica,2005,29(4):591-598.
Authors:YU Oiu-Shi  WANG Ji-he  LI Chang-long  ZHUANG Guang-hui  CHEN Shan-ke
Institution:1 Gansu Desert Control Research Institute, Wuwei, Gansu 733000, China
2 Alashan Grassland Station of Inner Mongolia, Alashan Zuoqi, Inner Mongolia 750300, China
Abstract:Ammopiptanthus mongolicus, which is an endemic and endangered species in China listed in the Red Data book, is a type of evergreen broad-leaved shrub in dry deserts of Asia. A. mongolicus is distributed mainly in the Alashan region of Inner Mongolia, but, for unknown reasons, the range of the population has been declining. We studied the distribution patterns and characteristics of A. mongolicus as a preliminary step in understanding the dynamic changes of the population and community and the factors causing the population decline. In Alashan Zuoqi, 36 quadrats (20 m×20 m) and 150 grids (5 m×5 m) were set up at 3 sites (Dongqingliang, Sumutu and Luanjingtan). There were at least 12 quadrats and 50 grids in every plot. The distribution patterns, stand density characteristics, morphological characteristics, and dynamic changes of the A. mongolicus populations at the 3 sites were compared. The results showed that A. mongolicus populations formed different distribution patterns under environmental conditions. The population was distributed evenly on flowing-sand or semi-fixed windy sand but was distributed contagiously on ancient riverbeds or stone slopes caused by seasonal floods. Individuals of A. mongolicus had different morphologies based on the population density and environment characteristics. On flowing-sand, individuals had shorter heights and smaller diameters but the relationship between height and width was not significant (R1=0.096). There was a negative relationship between population density and the height and diameter of individuals in the population on flowing-sand (R2=-0.214, R3=-0.339). Individuals growing on semi-fixed windy sand and stone slopes had significantly greater heights and diameters, but there was no significant relationship between population density, and the diameter and the height. On stone slopes, the relationships between individual diameters and the heights were not significant (R1 = 0.886), and there were no significant relationships between population density and height and width (R2 = 0.089, R3= 0.055). The densities of A. mongolicus populations were the highest at the flowing-sand site and the lowest at the stone slope population where seasonal floods occurred. Populations of A. mongolicus had different age structures at the different sites. At the flowing-sand site, there were even numbers of mid- to old-aged individuals but few young individuals, indicating that the population was senescing. At the semi-fixed windy sand and stone slope sites, there were also very few young individuals, and the number of individuals in the different age classes was distributed very unevenly. All three populations had limited the regeneration questioning the long-term viability of these populations.
Keywords:Population  Ammopiptanthus mongolicus  Environmental heterogeneity  Distribution pattern  Endangered species
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