吉林蛟河不同演替阶段针阔混交林乔木幼苗数量组成及其时间动态  

Composition and temporal dynamics of tree seedlings at different successional stages of conifer and broad-leaved mixed forests in Jiaohe, Jilin Province, China

作　　者：闫琰[1] 张新娜[1] 姚杰[1] 张春雨[1] 赵秀海[1] 

机构地区：[1]北京林业大学森林资源与生态系统过程北京市重点实验室,北京100083

出　　处：《植物生态学报》2016年第2期127-139,共13页Chinese Journal of Plant Ecology

基　　金：国家"十二五"科技支撑计划项目(2012-BAD22B0203)

摘　　要：为了解蛟河地区木本植物幼苗的数量特征及其年际动态,以及影响幼苗数量的生态学过程,该文以不同演替阶段针阔混交林监测样地为基础,在样地内共设置了451个种子雨-幼苗观测样站。通过2012–2014年连续3年的幼苗监测调查,对木本植物幼苗物种组成、数量特征、高度级结构及其年际动态进行了分析,并用多元回归的方法分析了幼苗数量与林分类型、同种成体胸高断面积之和及林冠开阔度的关系。结果表明:(1)林下幼苗层主要木本植物的组成在不同演替阶段林分中差异不大,并与样地内主要树种组成保持着一定相似性,但幼苗重要值排序在年际间和不同演替阶段稍有波动。(2)3个样地内幼苗个体数量和物种数都主要集中在5–20 cm高度级之间,之后随高度级增加而逐渐减少,但幼苗个体数量减少更快。表明与种间竞争相比,物种内部的相互作用是导致幼苗死亡的主要原因,证实了负密度制约效应在幼苗更新过程中的作用。(3)5个主要树种的幼苗数量都与同种成体胸高断面积之和呈显著的正相关关系,还呈现出明显的生境偏好,表明扩散限制和生态位过程也会影响幼苗的数量和分布。该文间接证实了负密度制约效应、扩散限制和生态位过程对温带地区不同演替阶段森林群落中幼苗数量组成的影响。Aims Our objective was to explore the composition and temporal dynamics of woody plant seedlings and the ecological processes that affect the amount of seedlings in Jiaohe, Jilin Province, China. Methods We established a total of 415 seed-seedling census stations in three large permanent feld plots belong- ing to three successional stages in the conifer and broad-leaved mixed forests. Based on three seedling censuses from 2012 to 2014, we analyzed species composition, quantitative character, height-classes structure and their inter-annual dynamics. Multiple linear regression was used to test the relationship between the abundance of seed- lings for five major species and the forest types, the sum of the basal area of conspecific adult within 20 m away from a seed trap, as well as canopy openness. Important findings Our results show that： （1） The species composition of seedlings slightly varied among dif- ferent successional stages, and was similar with that of trees in the plots. The rank of important values for seedling species among different years and successional stages varied slightly. （2） The number of seedlings and seedling species distributed mainly between 5-20 cm height classes, and decreased with the increasing height class. The number of seedlings decreased faster than that of seedling species, indicating that compared with interspecific competition, intraspecific competition was the main driver that led to seedling death. It confirmed the role of the negative density dependence in affecting seedling regeneration. （3） The amount of seedlings for all of the five major species was significantly positively related to the sum of the basal area of conspecific adults, which indicated that the quantity and distribution of seedlings were affected by dispersal limitation as well as nicheprocesses. Our research confirmed the role of negative density dependence, dispersal limitation and niche proc- esses on seedling composition.

关 键 词：幼苗组成 演替阶段 负密度制约 扩散限制 生态位 

分 类 号：S718.5[农业科学—林学]