人工林下紫茎泽兰种子雨与种群结构特征及其关系

Seed Rain and Population Structure Characteristics of Ageratina adenophora and Their Relationship in Forest Plantations

种子雨是植物种子扩散的起始,对植物群落的维持、更新以及定植具有重要作用。种子传播是紫茎泽兰入侵传播的主要方式。以紫茎泽兰为研究对象,基于培养皿捕获种子法,在细微尺度下探讨干香柏人工林中紫茎泽兰种子雨与种群结构的特征,并分析种子雨与种群结构之间的关系。结果表明,紫茎泽兰平均种子雨密度为(750±865)粒/m^(2),最大值为7159粒/m^(2),最小值为0,种子雨密度在调查样方内空间分布格局变异较大;紫茎泽兰的种群结构特征都属于强变异水平,且空间格局变异较大,都属于聚集分布格局。经相关性分析可知,紫茎泽兰种子雨密度与植株密度、种子单位面积结实量、株高具有极显著相关性,与实生苗密度没有相关性。因此,紫茎泽兰种群结构特征对种子雨具有显著影响,为了控制紫茎泽兰的迁移定植,最重要的是要消灭种源,加强人工林的经营管理。

Seed rain is the beginning of seed dispersal and plays an important role in the maintenance,renewal and planting of plant populations.Seed dispersal is the main mode of invasion and spread of Ageratina adenophora.In this paper,A.adenophora was selected as the research object to study the characteristics and relationship between seed rain and population structure in Cupressus duclouxiana plantation based on the method of culture dish capture seeds under the microscopic scale.The results showed that the average density of seed rain of A.adenophora was(750±865)seeds/m^(2),the maximum was 7159 seeds/m^(2),and the minimum was 0.The spatial distribution pattern of seed rain density of A.adenophora varied greatly in the survey plots.The population structure characteristics of A.adenophora had strong variation,and the spatial pattern variation was large,which belonged to the aggregation distribution pattern.Correlation analysis showed that the seed rain density was significantly correlated with population density,seed yield per unit area and plant height,but not with seedling density.Therefore,the correlation of the population structure characteristics of A.adenophora and seed rain was significant.In order to control the migration and planting of A.adenophora,it was the most important to eliminate seed sources and strengthen the management of forest plantation.