苔藓对喀斯特城市林下土壤生态化学计量特征的影响

Effects of moss on stoichiometric characteristics of soil ecology in karst urban forest

  • 摘要: 【目的】 探究苔藓对喀斯特城市林下土壤生态化学计量特征的影响,为揭示苔藓在喀斯特城市林下生态系统中的作用提供理论依据。【方法】 以贵州省贵阳市观山湖区观山湖公园为研究区域,选取常绿针叶林、竹林、落叶阔叶林、针阔叶混交林、常绿落叶阔叶混交林和常绿灌木林6种林分,采集苔藓覆盖土壤、裸地土壤及苔藓,测定土壤和苔藓碳(C)、氮(N)、磷(P)含量,分析其化学计量特征。【结果】 与裸地土壤相比,6种林分的苔藓覆盖土壤N含量和氮磷比(N∶P)均显著增加(P<0.05,下同)。除常绿落叶阔叶混交林外,其他林分的苔藓覆盖土壤碳磷比(C∶P)均显著高于裸地土壤。苔藓覆盖促进常绿针叶林、竹林、落叶阔叶林和常绿灌木林4种纯林的林下土壤C累积。竹林的苔藓覆盖土壤C、N、P含量分别为99.06、0.79和11.79 g/kg,均高于其他5种林分,其中P含量与其他林分差异显著。不同林分中,针阔叶混交林的苔藓C和N含量最高(0.24和0.29 g/kg),常绿针叶林的苔藓P含量最高(4.12 g/kg),竹林的苔藓C∶N和C∶P分别为1.27和0.17,均高于其他5种林分,其中C∶P与其他林分差异显著。相关分析结果显示,苔藓N含量与土壤C∶N呈显著正相关。双因素方差分析结果表明,林分类型、有无苔藓覆盖及其交互作用对土壤和苔藓C、N、P化学计量比均有显著影响。通过冗余分析(RDA)发现,郁闭度对苔藓C、N、P含量及化学计量比均有显著影响。【结论】 苔藓对喀斯特城市林下土壤C、N、P化学计量特征具有潜在影响,苔藓覆盖对改善喀斯特地区土壤N缺乏具有积极作用,竹林中苔藓覆盖土壤的养分累积效应最明显。进行林地管理和改造时,可优先培育竹林,以充分发挥苔藓对土壤养分的富集作用。

     

    Abstract: 【Objective】 To explore the effects of moss on the stoichiometric characteristics of soil ecology in karst ur‐ ban forest,and to provide theoretical basis for revealing the role of moss in karst urban forest ecosystem. 【Method】 Guan‐ shanhu Park in Guanshanhu District of Guiyang City,Guizhou Province was selected as research area,6 forest species, including evergreen coniferous forest,bamboo forest,deciduous broad-leaved forest,coniferous and broad-leaved mixed forest,evergreen and deciduous broad-leaved mixed forest and evergreen shrub,were selected,moss-covered soil,bare soil and moss were collected,and the contents of carbon(C),nitrogen(N)and phosphorus(P)in soil and moss were determined,and their stoichiometric characteristics were analyzed. 【Result】 Compared with the bare soil,the N content and N∶P ratio(N∶P)in the moss-covered soil of 6 stands were significantly increased(P<0.05,the same below). The C∶P ratio(C∶P)in moss-covered soil was significantly higher than that in bare land soil except for evergreen and deciduous broad-leaved mixed forest. Moss cover promoted soil C accumulation in 4 pure forests:evergreen coniferous forest,bamboo forest,deciduous broad-leaved forest and evergreen shrub. The contents of soil C,N and P in the moss-covered soil of bamboo forest were 99.06,0.79 and 11.79 g/kg respectively,which were higher than those of the other 5 stands,and the P content was significantly different from that of other stands. Among the different stands,the content of moss C and N was the highest(0.24 and 0.29 g/kg)in the coniferous and broad-leaved mixed forest,the content of moss P was the high‐ est(4.12 g/kg)in the evergreen coniferous forest,and the C∶N and C∶P of moss in the bamboo forest were 1.27 and 0.17 respectively,which were higher than the other 5 stands,and the difference of C∶P was significant. The results of correlation analysis showed that the content of moss N was significantly positively correlated with soil C∶N. The results of twofactor analysis of variance showed that the type of stand,moss cover or not and their interaction effects had significant in‐ fluence on the stoichiometric ratios of C,N and P of soil and moss. Redundancy analysis(RDA)revealed that the degree of canopy had significant influence on the contents and stoichiometric ratios of C,N and P of moss. 【Conclusion】 Moss has potential influence on the stoichiometric characteristics of C,N and P of soil in karst urban forest,and moss cover has positive effect on the improvement of soil N deficiency in karst area,and the soil nutrient accumulation effect of moss cover in bamboo forest is the most obvious. During forest land management and transformation,priority can be given to cultivating bamboo forests in order to give full play to the effects of moss on soil nutrient enrichment.

     

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