赣南地区生态公益林5种森林类型土壤有机碳特征

Characteristics of soil organic carbon for five typical ecological forest in southern Jiangxi Province

生态公益林作为林业建设的主体,在维护生态平衡方面发挥着重要作用,而森林土壤有机碳库作为森林生态系统碳库的重要组成部分,对维持全球碳平衡具有重要意义,探讨生态公益林不同森林类型的土壤有机碳分布特征,旨在为准确确定森林土壤碳储量以及生态公益林管理提供理论参考。本文以赣南地区5种主要森林类型(马尾松林、常绿阔叶林、杉木林、针叶混交林、针阔混交林)为研究对象,对不同土壤层次的有机碳含量和碳密度进行了测定和初步研究。结果表明:1)土壤有机碳含量整体表现为针阔混交林>常绿阔叶林>杉木林>针叶混交林>马尾松林,体现了森林类型的差异性;2)不同森林类型土壤有机碳密度介于2.70~6.15 kg·m-2之间,其中针阔混交林和常绿阔叶林土壤有机碳密度明显大于其他森林类型;3)土壤有机碳含量与土壤理化性质中的速效磷、速效钾、速效氮、全氮、全磷、容重等呈极显著性相关(P<0.01),与全钾呈现显著性相关(P<0.05),与pH值相关性不显著。结果说明,相对于针叶林,赣南地区针阔混交林与常绿阔叶林更有利于提高森林土壤的碳汇功能,因此建议在今后的生态公益林建设中,应注重加强对阔叶林和混交林的保护,积极促进针叶林向针阔混交林和常绿阔叶林方向转变,以提高森林生态系统的碳汇能力。

Ecological forest as the subject of forestry construction,plays an important role in maintaining ecological balance,while the forest soil organic carbon(SOC)as a component of soil carbon cool,is important for keeping balance of global carbon.Discussion on the SOC distribution features based on the different forest types of ecological forest,aims at providing the theory references for evaluating the forest carbon storage exactly and ecological forest management.The main five forest types(Pinus massoniana forest,evergreen broadleaved forest,Cunninghamia lanceolata forest,coniferous mixed forest,coniferous broadleaved mixed forest)were selected to study content of soil organic carbon(SOC)and soil organic carbon content density(SOCD).The results showed that:(1)The descending order of SOC was coniferous broadleaved forest,evergreen broadleaved forest,C.lanceolata forest,coniferous mixed forest,P.massoniana forest,indicating the difference of the five forest types.(2)The SOCD of different forests ranged from 2.70 to 6.15 kg·m-2,while the SOCD of coniferous broadleaved forest and evergreen broadleaved forest was higher than the others.(3)The SOC had a significant correlationship with available P,available K,available N,total N,total P,total K,while had an insignificant correlationship with pH.Furthermore,the result reveals that coniferous broadleaved mixed forest and evergreen broadleaved forest are more helpful for carbon sink capacity than the coniferous forest.Therefore,we are looking forward to protect the coniferous broadleaved mixed forest and the evergreen broadleaved forest,and converting the stand structure from coniferous plantation to coniferous broadleaved mixed forest,even evergreen broadleaved forest by transformation,then promoting the carbon sink capacity of forest ecological system.