东北温带针阔混交林不同演替阶段树木种群动态及其与功能性状的关系

Population dynamics and its relationship with functional traits in different succession stages of temperate mixed coniferous broad-leaved forest in Northeast China

功能性状表征植物对外界环境的响应和适应能力,进而影响着种群动态。植物功能性状如何驱动温带森林种群动态(生长、死亡和增补)以及不同演替阶段是否存在差异仍不清楚。本研究以长白山次生杨桦林(演替前期)和阔叶红松林(演替后期)共有的35个树种为对象,测量水力、木材和叶片等8个功能性状,分析不同演替阶段森林植物种群动态的内在联系以及植物功能性状与种群动态的关系。结果表明:随着演替进行,种群动态间的相关性逐渐增加。在次生杨桦林内,树木生长率和死亡率存在显著负相关关系,生长率和增补率不相关,增补率和死亡率不相关;在阔叶红松林内,树木生长率与死亡率和增补率均呈显著负相关,而增补率与死亡率则呈显著正相关。功能性状能够有效预测温带针阔混交林的种群动态,其预测能力在不同演替阶段间存在差异。与演替前期的次生杨桦林相比,功能性状,尤其是木质部水力性状(胡伯尔值)和解剖性状(平均导管直径),对演替后期的阔叶红松林树木生长率、死亡率和增补率的解释力度更高。本研究揭示了演替后期的针阔混交林种群动态间及其与功能性状间具有更强的规律性特征。

Functional traits regulate plant response to environmental changes,with consequences on population dy-namics.However,how plant functional traits impact population dynamics,including growth,mortality,and recruit-ment,remains elusive in temperate forests across different successional stages.In this study,we compiled data on population dynamics and eight functional traits,encompassing hydraulic,wood,and leaf traits,from 35 species commonly found in a secondary poplar-birch forest and a broad-leaved Korean pine forest in Northeast China.We quantified the intrinsic relationships between plant population dynamics and assessed how plant functional traits in-fluenced these dynamics.The results demonstrated a gradual increase in the correlation among population dynamics as forest succession progressed.In the secondary forest,tree growth rate and mortality rate were negatively correla-ted,while growth-death rate and growth-recruitment rate were not related.Conversely,in the broad-leaved Korean pine forest,there was a significant negative correlation between tree growth rate and mortality rate,as well as be-tween growth rate and recruitment rate,while tree mortality rate positively correlated with recruitment rate.Addi-tionally,functional traits effectively predicted population dynamics,but the predictive ability varied across succes-sional stages.Functional traits,particularly xylem hydraulic traits(e.g.,Huber value)and anatomical traits(e.g.,mean xylem conduit diameter),were stronger predictors of tree growth,mortality,and recruitment rates at the late successional stage compared with the early stage.These findings indicated that population dynamics and functiona traits exhibited strong regularity in the late successional stage of broad-leaved Korean pine forests.