摘要
【目的】望天树是热带雨林标志种及国家一级濒危树种,人工栽培是扩大其种群数量的重要途径。通过对望天树人工纯林及混交林的土壤理化性质、土壤微生物生物量碳氮及养分含量的分析,为望天树人工幼林混交树种选择及土壤管理提供参考。【方法】在望天树人工纯林、望天树-降香黄檀及望天树-巨尾桉混交林设置标准地,采用对角线法采集不同土层的土样,测定土壤pH值、有机质及养分含量、微生物生物量碳氮含量,利用生态化学计量和主成分分析方法研究不同林分和土层对土壤微生物生物量碳氮含量及土壤质量的影响。【结果】(1)土壤微生物生物量碳氮和土壤养分含量的垂直分布特征表现为随着土层深度的加深而下降,不同林分类型对其垂直分布影响不明显。(2)望天树人工幼林平均土壤C∶N∶P为35∶2∶1,土壤微生物生物量MBC∶MBN为8∶1。不同树种组成显著影响着土壤养分和微生物生物量碳氮及其化学计量比,望天树-巨尾桉混交模式可以明显提高土壤微生物活性,改善土壤质地和微环境。(3)相关性和主成分分析表明,望天树林地土壤微生物可以通过自身调节对土壤养分的变化保持一定的内稳性,土壤微生物生物量碳氮可以作为土壤养分储备库和碳氮源变化的早期生物指示指标。望天树-巨尾桉混交林对土壤微生态功能、质量和肥力状况的影响最显著,是最有利于望天树幼林林地土壤微生物生长、土壤养分发育的一种林分类型。【结论】望天树人工幼林土壤微生物生物量碳氮、养分含量及其化学计量特征表现出明显的表聚效应,且树种组成对其垂直分布影响不明显。望天树混交林相比纯林而言,对土壤微生物环境和土壤质量的促进效果更明显,其中望天树-巨尾桉混交模式更有利于养分活化,提高微生物群落功能及改善林地土壤结构,是望天树幼林时期和桉树纯林改造较合适的混交模式选择。
[Objective]Parashorea chinensis is a tropical rainforest species and a national first class endangered tree species,and the artificial cultivation is an important way to expand its population size.This study analyzed the soil physicochemical properties,soil microbial biomass carbon(SMBC),nitrogen(SMBN)and soil nutrient contents with their stoichiometric characteristics in different stands and soil layers of the young P.chinensis plantation,providing referable evidence for the optimal selection of mixed tree species and soil management.[Method]The standard sites were set up in P.chinensis artificial pure and mixed plantations and the soil samples of different soil layers were collected by diagonal method.The soil pH value,organic matter and nutrient content,SMBC and SMBN content were measured,further it was discussed about the effects of different stands and soil layers on the contents of SMBC and SMBN and the soil quality by ecological stoichiometry and principal component analysis.[Result](1)The vertical distribution characteristics of SMBC,SMBN and soil nutrient content decreased with the deepening of soil depth,different stand types had no obvious effect on its vertical distribution.(2)The average soil C∶N∶P of P.chinensis plantation was 35∶2∶1,average SMBC∶SMBN was 8∶1.The composition of different tree species significantly affected the changes of soil nutrients,SMBC,SMBN and their stoichiometric ratio,the mixed plantation of P.chinensis and Eucalyptus grandis×E.urophylla could improve the soil microbial activity,soil texture and microenvironment.(3)Correlation and principal component analysis revealed that:the soil microorganism in Parashorea chinensis plantation could maintain a certain internal stability through self-regulation,and SMBC,SMBN might be used as early biological indicators of changes in soil nutrient reserves and C,N sources.The mixed P.chinensis and Eucalyptus grandis×E.urophylla plantation had the most significant effect on soil microecological function,quality and fertility,which suggested that this stand type could be more favorable for the growth of soil microorganism and the development of soil nutrients in young Parashorea chinensis forest land.[Conclusion]The contents of SMBC,SMBN and nutrients with their stoichiometric characteristics of P.chinensis plantation show obvious surface accumulation effect,and the composition of tree species has no obvious effect on its vertical distribution.Compared with the pure plantation,the P.chinensis mixed plantation has more significant effect on soil microbial environment and soil quality.Particularly,the mixed plantation of P.chinensis and Eucalyptus grandis×E.urophylla better improve the function of microorganism and soil structure as well as the activation of nutrients,indicating that this mixed pattern can be selected as the appropriate choice for young P.chinensis plantation and one of the suitable transformation ways for pure Eucalyptus plantation.
作者
李万年
黄则月
赵春梅
杨梅
Li Wannian;Huang Zeyue;Zhao Chunmei;Yang Mei(Guangxi Key Laboratory of Forest Ecology and Conservation,College of Forestry,Guangxi University,Nanning 530004,Guangxi,China;Forestry Pest Management and Quarantine Station of Yangzhou,Yangzhou 225000,Jiangsu,China;Guangxi Nanning Liangfengjiang National Forest Park,Nanning 530031,Guangxi,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2020年第12期51-62,共12页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(31960307),广西自然科学基金项目(2018GXNSFAA28110)。
关键词
望天树
人工林
土壤养分
土壤微生物生物量碳氮
化学计量特征
Parashorea chinensis
plantation
soil nutrient
soil microbial biomass carbon and nitrogen
stoichiometric characteristics
