我国南亚热带乡土珍贵树种人工幼林不同器官营养元素储量及分配特征

The Nutrient Element Reserves and Distribution Characteristics of Different Organs of Artificial Young Forests of Precious Native Tree Species in the South Asia Tropical Region of China

为了阐明我国南亚热带主要乡土珍贵阔叶造林树种营养元素储量及分配特征,以广西9年生的主要乡土珍贵树种红锥(Castanopsis hystrix)、火力楠(Michelia macclurei)、格木(Erythrophleum fordii)、荷木(Schima superba)、蚬木(Excentrodendron tonkinense)、西南桦(Betula alnoides)、任豆(Zenia insignis)、降香黄檀(Dalbergia odorifera)和柚木(Tectona grandis)为试验对象,分析8种营养元素(N、P、K、Ca、Mg、Fe、Zn、Mn)在各树种的储量及分配特征。结果表明:9个树种单株营养元素总储量存在显著差异(P<0.05),由大到小顺序为:火力楠、红锥、荷木、柚木、降香黄檀、蚬木、西南桦、格木、任豆,不同树种不同器官之间、不同元素储量之间也存在显著差异(P<0.05)。不同营养元素在9个树种中储量占总储量的比例不同,所有树种排位前三的均为N、K、Ca,占总元素储量比例的85.5%~93.1%。9个树种由于自身的生理特性,对元素的需求和积累能力存在差异,其中,荷木及火力楠对Mn元素的吸收固定能力较强;蚬木对N、Mg、Fe、Zn、Mn营养元素的积累能力较低;降香黄檀对P、Zn、Mn的积累能力较低;格木对K、Ca的积累能力较低。9个树种对N、P、K、Ca、Mg、Zn、Mn营养元素的积累总体表现了茎最大,对Fe元素的存储主要集中于茎和根。9个树种每生产1 t干物质所需营养元素为8.08~25.23 kg,树种的营养总利用效率主要受树种生长特性的影响,速生树种营养利用效率相对较高,而慢生树种则相对较低。

To elucidate the nutrient element reserves and distribution characteristics of major native precious broadleaf afforestation tree species in the South Asia tropical region of China,this study focused on nine-year-old specimens of key native species from Guangxi:Castanopsis hystrix,Michelia macclurei,Erythrophleum fordii,Schima superba,Excentrodendron tonkinense,Betula alnoides,Zenia insignis,Dalbergia odorifera,and Tectona grandis.The analysis assessed the reserves and distribution characteristics of eight nutrient elements(N,P,K,Ca,Mg,Fe,Zn,Mn)across these species.The results indicated significant differences in the total nutrient element reserves per individual tree among the nine species(P<0.05),ordered from highest to lowest as follows:M.macclurei,C.hystrix,S.superba,T.grandis,D.odorifera,E.tonkinense,B.alnoides,E.fordii,and Z.insignis.Additionally,significant differences were observed in the reserves between different organs and among different elements within the various species(P<0.05).The proportion of different nutrient elements relative to the total reserves varied among the nine species,with nitrogen(N),potassium(K),and calcium(Ca)consistently ranking in the top three for all species,accounting for 85.5% to 93.1% of the total element reserves.Due to their physiological characteristics,the species exhibited differing demands and accumulation capabilities for nutrients.In particular,S.superba and M.macclurei demonstrated a strong capacity for Mn absorption and fixation.Conversely,E.tonkinense had lower accumulation capabilities for N,Mg,Fe,Zn,and Mn.Additionally,D.odorifera showed reduced accumulation capabilities for P,Zn,and Mn,while E.fordii had lower accumulation for K and Ca.Overall,the accumulation of nutrients N,P,K,Ca,Mg,Zn,and Mn across the nine species was greatest in the stems,while Fe storage was primarily concentrated in the stems and roots.The nutrient element requirement for producing 1 ton of dry matter ranged from 8.08 to 25.23 kg.The overall nutrient utilization efficiency was mainly influenced by the growth characteristics of the tree species,with fast-growing species exhibiting relatively higher nutrient utilization efficiency compared to slower-growing species.