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种群的点格局特征是植物群落生态学关系与过程在空间格局上的表现形式,是种群和群落结构动态与稳定性的标志。在祁连山北坡西北针茅草原,采用Ripley的K(r)函数,定量分析了狼毒(Stellera chamaejasme)和西北针茅(Stipa krylovii)种群点格局特征。结果表明:随退化草地狼毒种群规模扩大,狼毒与西北针茅的种群密度和高度表现出规律性的变化趋势;狼毒种群在未退化和轻度退化草地中聚集分布格局显著,均匀分布和随机分布是中度和重度退化草地的主要分布类型;西北针茅种群在四个梯度中以随机分布最为显著,仅在轻度退化草地中在0-38cm尺度上表现为均匀分布。狼毒和西北针茅种群的点格局的不对称性变化,以及由此引起的植物种内、种间竞争和协同策略的改变,是草原植物应对干扰的种群更新途径选择。
The characteristics of the point pattern of the population are the forms of plant community ecology and the spatial pattern of the process, which are the hallmarks of the dynamics and the stability of population and community structure. The Stipa krylovii population characteristics of Stellera chamaejasme and Stipa krylovii populations were quantitatively analyzed using K (r) function of Ripley on the northwestern Stipa steppe of the Qilian Mountains. The results showed that the population density and height of Stellera chamaejasme and N. davidii tended to change regularly with the enlargement of the degraded Steppe venom population. The distribution pattern of Stellera chamaejasme population in the degraded and mildly degraded turfgrass was significant and uniform And stochastic distribution are the main distribution types of moderate and severely degraded grassland. The population of Stipa krylovii is the most stochastically distributed among the four gradients, and is uniformly distributed on 0-38cm scale only in mildly degraded grassland. Asymmetric changes in the spot pattern of S. lividans and N. davidiana populations, and the consequent changes in intraspecies, interspecific competition and synergistic strategies, are among the new ways of population-renewal options for grassland plants to intervene.