摘要
【目的】探究文山国家级自然保护区土壤微生物生物量碳氮沿海拔地带性植被的分布特征及其关键调控因子,为理解亚热带森林土壤碳氮循环过程及其调控机制提供基础数据参考。【方法】以保护区低海拔亚热带季风常绿阔叶林、中海拔半湿润常绿阔叶林和高海拔中山湿性常绿阔叶林3种典型地带性植被类型为研究对象,采用氯仿熏蒸法研究土壤微生物生物量碳氮含量沿海拔和土层的变化,并运用偏Mantel检验、Fourth-Corner方法解析植被多样性、土壤性质与微生物生物量碳氮之间的关系。【结果】1)土壤微生物生物量碳氮含量的海拔变化差异显著(P<0.05)。3个地带性植被群落的土壤微生物生物量碳氮含量随海拔升高呈增加趋势,即亚热带季风常绿阔叶林(15.75和2.84 mg·kg^(-1))<半湿润常绿阔叶林(28.05和4.95 mg·kg^(-1))<中山湿性常绿阔叶林(41.61和7.80 mg·kg^(-1))。2)各地带性植被带土壤微生物生物量碳氮含量均随土层加深而呈显著的减小趋势(P<0.05),0~10 cm土层微生物生物量碳氮含量分别是40~50 cm的4.26和3.22倍,且亚热带季风常绿阔叶林微生物生物量碳氮含量变幅(7.21和3.42倍)最大。3)偏Mantel相关性检验结果表明,微生物生物量碳氮含量与土壤全氮含量、有机质含量和pH值的关联性最强(P<0.01,r≥0.75),而与土壤含水量、密度、全钾含量的关联性次之(P<0.05,r>0.5);Fourth-Corner分析结果表明,亚热带季风常绿阔叶林的土壤微生物生物量碳氮含量仅与植被多样性(Shannon指数,Margalef指数,Pielou指数)极显著负相关(P<0.01);而在半湿润常绿阔叶林和中山湿性常绿阔叶林中,微生物生物量碳氮含量与土壤pH值呈极显著负相关(P<0.01),与枯落物厚度、有机质含量和全氮含量极显著正相关(P<0.01)。【结论】保护区土壤微生物生物量碳氮含量沿海拔变化主要受土壤全氮含量、有机质含量和pH值调控;低海拔样地土壤微生物生物量碳氮含量主要受植物群落多样性所调控,而高海拔样地土壤微生物生物量碳氮含量的主控因子为枯落物厚度、pH值、有机质含量和全氮含量。
【Objective】This study is aimed to explore the distribution and main influencing factors of microbial biomass C and N across three different altitudinal vegetation zones,which provides baseline data for understanding the process of soil carbon and nitrogen cycling and its regulation mechanism in subtropical forest.【Method】We used the chloroform fumigation method to measure changes in microbial biomass C and N along altitudinal gradients and soil layers in three typical vegetation zones(i.e.,subtropical monsoon evergreen broad-leaved forest,sub-humid evergreen broad-leaved forest,and humid evergreen broad-leaved forest).The partial Mantel’s test and Fourth-Corner method were used to analyze the relationships of microbial biomass C and N to vegetation diversities and soil properties.【Result】1)The altitudinal variation of soil microbial biomass C and N were significant(P<0.05).Soil microbial biomass C and N in communities of the three vegetation zones increased with the rise of altitudes,in an order of subtropical monsoon evergreen broad-leaved forest(28.05,4.95 mg·kg^(-1))<semi-humid evergreen broad-leaved forest(15.75,2.84 mg·kg^(-1))<humid evergreen broad-leaved forest(41.61,7.80 mg·kg^(-1)).2)Soil microbial biomass C and N significantly decreased with the depth of soil layers(P<0.05).Soil microbial biomass C and N were 4.26 and 3.22 times,respectively higher in 0-10 cm layer than in 40-50 cm layer.The largest range of vertical variations in biomass C and N(7.21 and 3.42 times,respectively)was observed in subtropical monsoon evergreen broad-leaved forest.3)Partial Mantel correlation test showed that microbial biomass carbon and nitrogen had the strongest correlation with total nitrogen,soil organic matter,and pH value(P<0.01,r≥0.75),followed by the correlation with soil moisture content,bulk density,and total potassium(P<0.05,r>0.5).The fourth corner analysis showed highly negative correlations of soil microbial biomass C and N with the vegetation diversity(i.e.,Shannon,Margalef,and Pielou index)(P<0.01)in the subtropical monsoon evergreen broad-leaved forest,and highly negative correlation with soil pH but highly positive correlation with litter thickness,organic matter and total nitrogen(P<0.01)in the semi-humid evergreen broad-leaved and humid evergreen broad-leaved forests in the middle vegetation zone.【Conclusion】The altitudinal variation of soil microbial biomass C and N were mostly controlled by total nitrogen,soil organic matter,and soil pH,but mainly by vegetation community diversity at low altitudes,and by litter thickness,soil pH,soil organic matter,and total nitrogen at high altitudes.
作者
李聪
吕晶花
陆梅
杨志东
刘攀
任玉连
杜凡
Li Cong;Lu Jinghua;Lu Mei;Yang Zhidong;Liu Pan;Ren Yulian;Du Fan(College of Ecology and Soil and Environment,Southwest Forestry University,Kunming 650224;College of Forestry,Southwest Forestry University,Kunming 650224;College of Life sciences,Guizhou University,Guiyang 550025)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2022年第3期20-30,共11页
Scientia Silvae Sinicae
基金
国家自然科学基金地区科学基金项目(42067011)
云南省应用基础研究面上项目(202001AT070113)
云南省中青年学术技术带头人后备人才项目
云南省应用基础研究面上项目(2013FB053)
西南林业大学博士启动基金(111901)
西畴县高等植物与植被类型多样性调查与评估(2166095)
云南省高校优势特色重点学科(05000511311)。
关键词
地带性植被
微生物生物量碳氮
植被多样性
分布特征
文山国家级自然保护区
vegetation zones
microbial biomass carbon and nitrogen
vegetation diversity
distribution characteristics
Wenshan National Nature Reserve
