摘要
灌木是森林生态系统的重要组成部分,在维持物种多样性、促进养分循环、保护幼苗更新以及促进营养级相互作用等方面具有重要作用,其存活情况对森林群落组成和生态系统功能具有重要意义。但亚热带森林中灌木的存活情况及其影响因素仍有待探究。本研究依托于中国亚热带森林生物多样性与生态系统功能实验研究平台(BEF-China),利用105个不同乔木与灌木多样性相嵌套样方中2012年和2019年的灌木个体存活数据,以及样方水平的土壤养分数据、地形数据、物种多样性数据和物种水平的功能性状数据,通过构建一系列广义线型混合模型(GLMM)探讨了非生物因素、生物因素以及灌木功能性状对灌木存活的影响。结果表明:不同灌木物种的存活率具有显著差异。坡度较小的山谷、山鞍部位以及土壤碳氮比较高的环境更有利于灌木存活;乔木和灌木多样性对灌木存活影响有限,但乔木多样性的增加可通过形成更郁闭的林冠提高灌木存活;灌木功能性状显著影响灌木存活,且倾向于保守型生活策略(即较小的比叶面积、叶片氮含量、气孔大小,较高的叶干物质含量、木质密度)的灌木物种具有更易于存活。通过模型比较发现,包含所有因素的全模型对灌木存活的解释度最高,不同影响因素的贡献率由大到小依次为非生物因素、灌木功能性状以及生物因素。本研究表明灌木存活受到多方面因素的共同影响,尽管土壤和地形等非生物因素的变化影响了灌木的存活,但不同灌木由于功能性状间的差异同样形成了不同的存活表现,而物种多样性的直接影响可能需要更长时间的监测才能更加显著。
Aims:Shrubs are a vital component of forest ecosystems,playing an important role in maintaining species diversity,promoting nutrient cycling,protecting seedling regeneration,and fostering multi-trophic interactions.Shrub survival is an integral factor in forest community composition and function.However,previous studies lack insights on factors influencing shrub survival.Here,we examed the influence of different factors on shrub survival in order to understand the mechanisms underlying shrub survival.Methods:The study examined 105 plots with varying tree and shrub species diversity in the Biodiversity-Ecosystem Functioning Experiment China platform(BEF-China).By collecting shrub survival in 2012 and 2019,topographical variables,soil variables,tree and shrub species richness in plot level,associated with shrub functional traits in species level,we analyzed the effects of abiotic factors,biotic factors and functional traits on shrub survival using the generalized linear mixed model(GLMM).Results:We found significant differences in the survival rates among 10 shrub species.Shrubs tended to have higher survival rates in valleys or gently sloping saddles,and in plots with high soil C/N ratio.Neither tree nor shrub diversity had a significant effect on shrub survival,but tree diversity could indirectly improve shrub survival by forming a denser canopy.Shrub functional traits generally significantly affected their survival.For example,shrub species with conservative traits like low specific leaf area,low leaf nitrogen content,small stomatal area,high leaf dry matter content,and high wood density survived better.Abiotic factors had the largest impact on shrub survival,followed by shrub functional traits and then biotic factors.However,the best model for shrub survival included all the factors studied.Conclusion:The survival of shrubs is the joint result of many factors.Abiotic factors play an important role and differing functional traits also influence shrub survival.However,the impact of species diversity on shrub survival may need a longer window of observation.
作者
薛玉洁
程安鹏
李珊
刘晓娟
李景文
Yujie Xue;Anpeng Cheng;Shan Li;Xiaojuan Liu;Jingwen Li(School of Ecology and Nature Conservation,Beijing Forestry University,Beijing 100083;Zhejiang Qianjiangyuan Forest Biodiversity National Observation and Research Station,Institute of Botany,Chinese Academy of Sciences,Beijing 100093)
出处
《生物多样性》
CAS
CSCD
北大核心
2023年第3期19-29,共11页
Biodiversity Science
基金
国家重点研发计划(2022YFF0802300)
中国科学院先导科技专项(B类)(XDB31000000)。