摘要
以关帝山林区华北落叶松人工纯林为对象,将枯落物分为未分解层和半分解层,基于厚度将其划分为8组,探究枯落物未分解层和半分解层厚度对林地天然更新的影响,以推动华北落叶松天然更新及生态恢复。结果表明:枯落物未分解层厚度在0.32~0.83 cm,半分解层厚度在0.18~0.89 cm时,更新指数较大(≥0.15),林下更新较好;未分解层厚度>1.1 cm,半分解层厚度>0.5 cm时,更新指数较小(≤0.07),林下更新较差。冗余分析显示,枯落物未分解层厚度对天然更新解释能力高且稳定,贡献率为38.7%;半分解层厚度对天然更新影响不显著。结构方程模型表明,枯落物未分解层厚度增加种子萌发机械阻力,对天然更新有负向直接影响(-0.617),同时通过影响碱解氮和速效磷含量对天然更新产生正向间接影响(+0.178),综合双重作用(-0.439)表现为对人工林天然更新过程的抑制作用。综上,华北落叶松林下枯落物未分解层厚度与天然更新关系最为密切,半分解层厚度对天然更新影响较小。
In this study,we explored the thickness influence of undecomposed litter layer and semi-decomposed litter layer on the natural regeneration in an artificial pure forest of Larix principis-rupprechti in the forest area of Guandi Mountain.We divided the litter into an undecomposed layer and a semi-decomposed layer,which was further divided into eight groups based on the thickness.The results showed that when the thickness of undecomposed layer was 0.32-0.83 cm,and that of semi-decomposed layer was 0.18-0.89 cm,the regeneration index was larger(≥0.15),and the regeneration was better.When the thickness of undecomposed layer was more than 1.1 cm and that of semi-decomposed layer was more than 0.5 cm,the regeneration index was smaller(≤0.07),and the regeneration of understory was worse.Results of redundancy analysis showed that the undecomposed layer thickness of ltter had a high and stable explanatory ability for natural regeneration,with a contribution rate of 38.7%,while the semi-decomposed layer thickness had no significant effect on natural regeneration.Structural equation modeling revealed that the thickness of undecomposed layer of litter increased the mechanical resistance to seed germination which had a negative direct effect on natural regeneration(-0.617),and a positive indirect effect on natural regeneration by influencing the content of alkali-hydrolyzed nitrogen and available phosphorus(+0.178).The combined effects(-0.439)showed an inhibitory effect on the natural regeneration.In conclusion,the thickness of undecomposed layer of litter under L.principis-rupprechti was most closely related to natural regeneration,and the thickness of semi-decomposed layer had a minimal effect on natural regeneration.
作者
姚佳峰
郭钰
董媛
隋想
吉星宇
杨南
魏曦
梁文俊
YAO Jiafeng;GUO Yu;DONG Yuan;SUI Xiang;JI Xingyu;YANG Nan;WEI Xi;LIANG Wenjun(College of Forestry,Shanxi Agriculture University,Jinzhong 030801,Shanxi,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2024年第4期1025-1032,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(32371970,31971644)
国家重点研发计划项目(2022YFF1300401)
山西省高等学校科技创新项目(2021L105)
山西省优秀博士来晋工作奖励资金科研项目(SXYBKY2018032)
汾河流域水土保持效益评价技术研究与应用项目资助。
关键词
天然更新
华北落叶松
枯落物厚度
冗余分析
结构方程模型
natural regeneration
Larix principis-rupprechtii
litter thickness
redundancy analysis
structural equation model
