五大连池火山熔岩台地植物多样性与土壤养分的关系

Species diversity and soil nutrients in lava platforms of Wudalianchi Volcanoes, China

采用空间序列代替时间序列的方法对五大连池不同年代火山熔岩台地进行样方调查,在得到物种组成和土壤养分的基础上,运用相关性分析探讨不同火山熔岩台地植物多样性及其与土壤养分之间的关系。结果表明:植物物种的科、属、种数量在新期火山中最低,随着火山形成年代的增加,老期火山植物物种的科、属、种数量最高;群落乔木层、灌木层的多样性指数、均匀度指数和丰富度指数在17万a火山具有最大值(P<0.05),群落草本层的多样性指数、均匀度指数和丰富度指数在28万a火山具有最大值(P<0.05)。随着火山形成年代的增加,这4项指数均呈现先增加后减小的趋势,支持了森林生态系统中间阶段具有较高物种多样性的"中度干扰假说";土壤pH值、全磷、全钾、速效钾质量分数在新期火山最高(290 a),显著高于老期火山(P<0.05),随着火山形成年代的增加呈现先减小后增加的趋势;土壤有机质、全氮、铵态氮、硝态氮、速效磷质量分数在40～50万a火山具有最大值,显著高于其他时期火山熔岩台地(P<0.05),随着火山形成年代的增加呈现先增加后减小的趋势。乔、灌、草不同层次多样性指数与土壤的pH值、全氮、全钾有明显的相关性。

To determine species composition and soil nutrients in different lava platforms as well as the relationship between plant diversity and soil nutrients,volcanic lava platforms of different ages in Wudalianchi were used as research samples using a spatial sequence approach instead of a temporal sequence and correlation analysis.Richness,Shannon-Wiener,Simpson,and Pielou indexes were also used.Results showed that as the age of the volcanoes increased,the number of genera and species of plants was lowest in new volcanic lava platforms and was highest in old volcanic lava platforms.Richness,Shannon-Wiener,Simpson,and Pielou indexes of tree and shrub were highest in volcanic lava platforms erupted at 170000 years than others (P<0.05),howere,Richness,Shannon-Wiener,Simpson,and Pielou indexes of herb layers were highest in volcanic lava platforms erupted at 280000 years than others (P<0.05),which all initially increased and then decreased in support of the "intermediate disturbance hypothesis" in the forest ecosystem.Total P,total K,available N,and pH in the soil was highest in new volcanic lava platforms(290 years) than others (P<0.05),which initially decreased and then increased.However,soil organic carbon,total N,ammonium N,nitrate N,and available P was highest in volcanic lava platforms erupted at 400000-500000 years than others(P<0.05),which initially increased and then decreased.Moreover,richness,Shannon-Wiener,Simpson,and Pielou indexes of different layers were positively correlated with pH,total N,and total K in the soil(P<0.05).[Ch,4 fig.3 tab.26 ref.].