武功山草甸—人工柳杉林土壤碳氮磷化学计量特征比较研究

发布时间：2018-08-09 17:35

【摘要】：江西武功山山地草甸,具有面积大和分布基准海拔低的特点,是气候变化的重要指示植被。由于木材需求量的增加,上世纪80年代,萍乡矿务局林场选择具有耐寒特性的柳杉(Cryptomeria japonica)大面积种植于草甸交错区域,保留至今。人工造林作为一种土地利用方式的改变,显著影响了武功山山地草甸的环境和土壤碳(C)、氮(N)、磷(P)特征变化。因此,本文以“草甸-柳杉林”土壤为研究对象,通过分析武功山草甸和柳杉林土壤C、N、P特征差异,探讨人工造林对武功山草甸土壤的影响机制,以期为武功山山地草甸脆弱生态系统恢复建设提供理论依据。研究结果表明:(1)通过典则判别函数分析草甸和柳杉林的多元空间下的分离程度发现草甸和柳杉林的分离程度较高。(2)柳杉林土壤全碳(TOC)、微生物量碳(MBC)、微生物量磷(MBP)、可溶性有机碳(DOC)、硝态氮(NO3--N)、铵态氮(NH4+-N)、有硝态氮(AN)可溶性总氮(DTN)含量等指标均高于草甸,pH值、全氮(TN)、全磷(TP)、微生物量氮(MBN)含量等指标均低于草甸;比较草甸-柳杉林土壤C、N、P化学计量比,发现土壤碳氮比值和土壤微生物量碳、氮、磷比值均无显著性差异,但柳杉林土壤C/N、C/P增加。(3)土壤TOC浓度与TN、MBN关系密切且呈显著性正相关,土壤MBC与MBN、MBP均呈显著性正相关;DOC与NH4+-N、NO3--N、AN、可溶性有机氮(DON)等之间的相关系数分别达到显著或极显著水平,NH4+-N、NO3--N均与AN、DTN呈显著性正相关。综上:武功山草甸-柳杉林在多元空间下分离程度高,柳杉人工林改变了草甸土壤C、N、P分布和含量组成。
[Abstract]:The mountain meadow in Wugong Mountain Jiangxi Province has the characteristics of large area and low distribution datum altitude and is an important indicator of climate change. Because of the increasing demand for wood, Pingxiang Mining Bureau Forest Farm selected (Cryptomeria japonica), which has the characteristic of cold tolerance, planted in the meadow interlaced area in large area in 1980s. As a change of land use, artificial afforestation significantly affected the environmental and soil carbon, (C), nitrogen, (N), and phosphorus (P) characteristics of mountain meadow in Wugong Mountain. Therefore, taking the soil of "meadow and Cryptomeria fortunei forest" as the research object, this paper discussed the mechanism of artificial afforestation on the meadow soil of Wugong Mountain by analyzing the difference of soil CnP characteristics between the meadow of Wugong Mountain and the soil of Cryptomeria fortunei forest. In order to provide theoretical basis for the restoration and construction of fragile ecosystem of mountain meadow in Wugong Mountain. The results showed that: (1) the degree of separation of meadow and Cryptomeria forest in multivariate space was analyzed by canonical discriminant function. (2) soil total carbon (TOC), microbial biomass carbon (MBC), microbial biomass (MBC), microbial biomass phosphorus (MBP), was found to be higher in meadow and Cryptomeria forest. The contents of soluble organic carbon (DOC),) nitrate nitrogen (NO3--N), ammonium nitrogen (NH4 -N), nitrate nitrogen (AN), soluble total nitrogen (DTN) were higher than those in meadow. The microbial biomass nitrogen (MBN) content of total nitrogen (TN), and total phosphorus (TP), was lower than that of meadow, and the ratio of soil C / N ratio and soil microbial biomass C, N and P ratio were not significantly different between meadow and Cryptomeria chinensis forest soil, compared with the stoichiometric ratio of soil C / N ratio and soil microbial biomass C, N, P ratio. But soil C / N / P increased in Cryptomeria chinensis forest. (3) soil TOC concentration was closely related to TNMBN and had a significant positive correlation. There was a significant positive correlation between soil MBC and MBNN MBP. The correlation coefficients between DOC and NH4-Nnno _ 3 N, soluble organic nitrogen (DON) and so on were significant or extremely significant, respectively. There was a significant positive correlation between soil MBC and NH4-Nno _ 3 N. On the other hand, the meadow and Cryptomeria fortunei forests in Wugong Mountain were highly segregated in multiple space, and the distribution and content of Cnn P in meadow soil were changed by Cryptomeria fortunei plantation.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

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