水位和草丘微地貌对巴音布鲁克高寒沼泽植物群落物种多样性的影响

Influence of Water Level and Hommock Microtopography on Species Diversity of Plant Communities in Bayanbulak Alpine Marshes

高寒沼泽是气候变化和人类活动的敏感区和预警区,了解高寒沼泽植物群落物种多样性与环境因子的关系,对于揭示其物种多样性的维持机制以及高寒沼泽的保护和管理具有重要意义。以巴音布鲁克高寒沼泽为研究对象,采用野外样线与样方调查相结合的方法,研究水位和草丘微地貌对巴音布鲁克沼泽植物群落物种多样性的影响。研究结果表明,出现在样地内的湿地植物共39种,隶属于19科22属;地表水水位直接影响沼泽植物群落的物种组成和多样性。随着地表积水的增加,沼泽植物物种丰富度明显降低,二者显著负相关(n=11,R2=0.77,p<0.001);随着水位的变化,常年积水区、季节性积水区、无积水区的植物物种丰富度依次增加。水位与草丘盖度显著负相关(n=11,R2=0.63,p<0.001),随着水位的升高,草丘盖度逐渐减小;草丘物种丰富度显著高于丘间(p<0.001),与丘间相比,草丘增加了45%的物种数,物种丰富度与草丘盖度显著正相关(n=11,R2=0.79,p<0.001),草丘盖度越高,沼泽物种越丰富。草丘微地貌主要通过增加表面积和生境异质性来促进沼泽的植物物种多样性。

Alpine wetlands are sensitive and alert to climate change and human activity. Exploring the relationships between the plant diversity and environmental factors are important to understand the biodiversity maintenance mechanism, and for the protection and management of alpine wetlands. In this study, the methods of line transect survey and plot survey were combined to study the influence of water level and hommock microtopography on species diversity of plant communities in Bayanbulak alpine marshes. A total of 39 plant species belonging to 19 families and 22 genera were identified in Bayanbulak alpine marshes. Species composition and richness were significantly affected by the surface water level. Species richness decreased significantly as the surface water level increased（n=11, R2=0.77, p〈0.001）. The plant species richness in seasonal water-logged zone was higher than that in perennial water-logged zone, but lower than that in no water-logged zone. The hummock coverage was negatively related to the surface water level（n=11, R2=0.63, p〈0.001）, and positively related with species richness（n=11, R2=0.79, p〈0.001）. The species richness of the hummock was significantly higher than that of the hollow, and the hummock increased the species richness by 45%. The results indicated that the hommock microtopography could foster high diversity by increasing surface area and by creating multiple micro-habitats.