桉树人工林土壤养分对凋落物分解的影响  

Effect of soil nutrient on the litter decompositionof Eucalyptus plantation interplanting herbage

作　　者：罗佳[1,2,3] 周小玲 陈建华[1] 韦铄星[4,5] 田育新[2,3] 张珉 蒋燚[4,5] 

机构地区：[1]中南林业科技大学,湖南长沙410004 [2]湖南省林业科学院,湖南长沙410004 [3]慈利森林生态系统国家定位观测研究站,湖南慈利427200 [4]广西壮族自治区林业科学研究院,广西南宁530002 [5]广西优良用材林资源培育重点实验室,广西南宁530002

出　　处：《中南林业科技大学学报》2017年第11期132-139,共8页Journal of Central South University of Forestry & Technology

基　　金：国家十二五科技支撑计划课题(2015BAD07B04);广西优良用材林资源培育重点实验室开放课题(14B0201);广西科学研究与技术开发计划项目(主席科技资金2012217-6);国家十二五环境领域科技支撑计划项目(2014BAC09B01)

摘　　要：以桉树人工林为研究对象,利用野外试验和室内分析相结合的方法,其中野外试验采取网袋法,系统研究了桉树人工林间作下土壤养分对凋落物分解的影响,可旨在为维护桉树人工林的长期生产以及实施人工林生态系统的经营管理提供理论支持。结果表明:桉树纯林凋落物叶和枝分解360 d后均比桉树+象草林低,比桉树+山毛豆林凋落物叶和枝分解低。不同间作模式下桉树凋落物叶和枝均先固持后释放;P含量变化不同,K、Ca、Mg含量均下降。桉树纯林土壤有机质降低34.8%,而桉树+象草林、桉树+山毛豆林土壤有分别增加147.3%和15.5%;3种林分土壤氮含量分别增加44.6%和2.9%,49.3%和12.8%,466.9%和68.9%。利用典范对应分析(CCA)得出桉树人工林凋落物分解速率、养分释放动态以及土壤养分关系明显,桉树凋落物叶和枝分解速率与土壤养分关系紧密,尤其是与土壤总磷含量。土壤总氮、有效氮、总磷和总钾对桉树凋落物叶氮含量和总磷养分释放影响较大,桉树人工林凋落物枝分解中,土壤有机质、总氮、有效磷与凋落物枝氮含量、总磷含量关系密切。间作桉树林促进桉树凋落物叶和枝分解,3种不同间作桉树人工林凋落物叶和枝分解均呈现快-慢-稍快模式,N元素质量分数属于富集-释放模式,P元素先下降后上升,除桉树+山毛豆枝凋落物外,属于释放-富集模式;K、Ca、Mg的质量分数随着分解过程一直下降,属于淋溶-释放模式,桉树纯林凋落物叶各养分元素释放速率是Mg>Ca>K>N>P,凋落物枝养分释放速率是Mg>K>Ca>N>P;桉树+象草人工林凋落物叶和枝均是Mg>K>Ca>N>P;桉树+山毛豆人工林凋落物叶是Mg>K>Ca>N>P,凋落物枝则是K>Mg>Ca>P>N,凋落物叶和枝中养分含量的释放尤其受土壤总氮和速效磷的调节。Taking Eucalyptus plantations as the research object, using the method of field experiment adopted net bag combining with indoor analysis, the effect of soil nutrient on the litter decomposition of Eucalyptus plantation interplanting herbage was studied, in order to provide theoretical basis for maintaining long-term production and managing plantation ecosystem of Eucalyptus plantation. The results showed that, the 360d decomposition of the pure Eucalyptus plantation leaf and branch litter was lower than that of the Eucalyptus ＋Elephant grass plantation and the Eucalyptus ＋Mountain tephrosia plantation. The nutrient content of leaf and branch litter changed obviously, and the litter P content dynamics differed from the other nutrients. The litter K, Ca, and Mg content declined with increasing decomposition time. The soil organic matter of the pure Eucalyptus plantation was reduced by 34.8%, but that of the Eucalyptus ＋Elephant grass plantation and the Eucalyptus ＋Mountain tephrosia plantation were increased by 147.3% and 15.5% respectively. The soil total N and hydrolysis N content in all the three forest stands types were increased by 44.6% and 2.9%,49.3% and 12.8%, 466.9% and 68.9% respectively. CCA analysis showed that, the litter decomposition rate and nutrient releasing dynamics were closely related to soil nutrient, the decomposition rate of leaf and branch litter had significant correlation with soil nutrient, especially with the soil total P content. Soil total N, available N, total P and total K had significant impact on leaf litter N content and total P nutrient releasing, and thesoil organic matter, total N, available P had significant correlation with branch litter N content and total P content in branch litter decomposition process. Interplanting type had clear impacts on nutrient release within litter type, and the leaf and branch litter decomposition presented fast-slow-slightly faster process. The N mass fraction initially increased and then declined, which is indicative of an enrichment-r

关 键 词：间作 凋落物分解 土壤养分 典范对应分析 

分 类 号：S792-39[农业科学—林木遗传育种]