青藏高原植物-土壤碳氮磷化学计量特征及其对环境因子的响应

发布时间：2018-01-10 15:30

本文关键词：青藏高原植物-土壤碳氮磷化学计量特征及其对环境因子的响应　出处：《天津师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：为阐明青藏高原高寒生态系统植物-土壤碳氮磷含量及化学计量特征,进一步研究青藏高原高寒生态系统碳、氮、磷元素在不同组分间的相互作用规律与机制,本研究以青藏高原中东部不同植被类型植物-土壤样点为研究对象,通过野外采样和室内测定,分析植物-土壤有机碳、全氮、全磷和C:N、C:P、N:P值的变化特征及其影响因素,初步阐明了青藏高原生态系统植物-土壤碳氮磷含量及化学计量特征及其对环境因子的响应机制,并探讨了植物-土壤碳氮磷及化学计量之间的相关性,以期揭示青藏高原种群内碳氮磷在不同组分间的相互作用与变化规律,为青藏高原高寒生态系统植物与土壤间的化学计量学特征研究提供基础的理论依据。主要研究结果如下:(1)本研究中,植物样品有机碳含量的平均值为368.23g·kg-1,其中,林地植物有机碳含量最高,灌丛草地含量最低,且林地植物有机碳平均值显著高于灌丛草地、荒草地的有机碳平均值含量;植物全氮含量的平均值为12.66g·kg-1,林地植物全氮含量最高,灌丛草地全氮含量最低,且林地平均值显著高于灌丛草地的平均值;植物全磷含量平均值为1.07g·kg-1,其中,荒草地全磷平均值最高,显著高于灌丛草地和高山草原,而与林地、高寒草甸、草地无显著差异。(2)研究区中植物C:N平均值为31.23,植物C:P平均值为401.52,明显高于全球平均水平的232;植物N:P平均值为13.68,接近全球水平13.8,同时略低于全国水平16.3。具体来说,研究区灌丛草原、高山草原植物主要受P限制,林地、荒草地、高寒草甸植物受到N、P两种元素的限制或两种元素都不缺少,草地主要受N限制。(3)研究区土壤有机碳、全氮、全磷含量平均值分别为22.01g·kg-1、1.61g·kg-1、0.53g·kg-1,其中,林地SOC、TN、TP含量均最高,荒漠最低。(4)本研究区表层土壤C:N平均值为15.24,略高于我国表层土壤C:N值(10～12);研究区表层土壤C:P平均值为40.1,低于中国表层土壤C:P值(135.88);研究区表层土壤N:P平均值为3.02,低于我国平均水平9.3。(5)垂直方向上,不同植被类型土壤有机碳、全氮、全磷均呈现下降趋势,普遍存在表面聚集现象,研究区剖面土壤C:N、C:P、N:P值对土壤深度的响应差异与土壤TN、TP的来源差异有密切关系。N:P作为重要的生理指标,在本研究区中除高山草原、盐碱地N:P值变化趋势不大之外,其余植被类型土壤N:P值随土壤深度的增加呈锯齿状下降。(6)由Pearson相关分析可得,除植物全氮含量与土壤硝态氮呈显著正相关关系外,植物碳、磷含量与土壤碳氮磷含量及其化学计量相关性均不显著。本研究中植物碳氮磷及其化学计量与土壤C:N、C:P、N:P相关性不明显,表现出在同一时段内植物碳氮磷与土壤不完全同步的模式。(7)通过逐步回归分析可知,植物OC与粉砂呈负相关关系,TN与黏粒呈负相关关系,TP与土壤无机碳呈正相关关系,各环境因子对植物C:N、C:P、N:P值影响不显著,变量均未进入回归方程。(8)由逐步回归方法可知,影响青藏高原土壤SOC的主要因子为pH值;影响土壤TN的因子从大到小依次为土壤Alk、pH值、黏粒含量;对于土壤TP,环境因子的影响程度从大到小排序为土壤pH值、海拔、Alk;影响青藏高原土壤C:N值的主要因子为年均温;对于C:P值和N:P值,影响最大的环境因子均为黏粒含量。
[Abstract]:In order to elucidate the plants of Alpine Ecosystem in Tibetan Plateau soil carbon nitrogen and phosphorus content and stoichiometry, further study of Alpine Ecosystem in Qinghai Tibet Plateau of carbon, nitrogen, phosphorus in different components of the interaction between law and mechanism, based on the central eastern Qinghai Tibet Plateau of different vegetation types in plant soil samples as the research object, through the field sampling and laboratory analysis, analysis of plant soil organic carbon, total nitrogen, total phosphorus and C:N, C:P, variation characteristics and its influencing factors of N:P value, illustrates the ecosystem of Qinghai Tibet plateau plant soil carbon nitrogen and phosphorus content and chemical stoichiometry and its response mechanism to environmental factors, and to explore the correlation between plant soil carbon and nitrogen and phosphorus chemical measurement, in order to reveal the Tibetan plateau within populations of carbon nitrogen and phosphorus in different components of the interaction and the change rule of soil and planting for the Alpine Ecosystem The stoichiometry of research provide a theoretical basis for the foundation. The main results are as follows: (1) in this study, the average value of the samples of organic carbon content in plants for 368.23g kg-1, the plant organic carbon content in forest was the highest, and the lowest content of shrub grassland, woodland plant organic carbon was significantly higher than the average shrub grassland, organic carbon the average content of grassland; the average value of total nitrogen content in plant was 12.66g kg-1, the total nitrogen content of woodland plant nitrogen content is highest, the lowest is the shrub meadow, woodland and shrub grassland was significantly higher than the average value; and the total phosphorus content of average value of 1.07g and kg-1, among them, the highest average yearly total phosphorus. Was significantly higher than that of shrub grassland and alpine grassland, and forest, alpine meadow, meadow. There was no significant difference between C:N (2) plants in the study area with an average of 31.23 plants, the average of C:P was 401.52, significantly higher than the global average Of the 232 plants; the average value of N:P is 13.68, close to the global level 13.8, also slightly lower than the national level of 16.3. specifically, study area, shrub steppe and alpine grassland plants mainly limited by P, woodland, grassland, alpine plants such as N, P two elements restrict or two elements are not lack of grass the main limitation of the N. (3) the study area of soil organic carbon, total nitrogen, total phosphorus content average value were 22.01g - kg-1,1.61g - kg-1,0.53g - kg-1, among them, SOC TN, TP in woodland, were the highest, lowest desert. (4) C:N soil layer in the study area, the average value is 15.24, slightly higher than that of soil C:N the surface value (10 ~ 12); soil surface area of C:P with an average of 40.1, lower than Chinese soil C:P values (135.88); N:P in the soils of the study area with an average of 3.02, lower than the average level of China's 9.3. (5) on the vertical direction, different vegetation types, soil organic carbon, total nitrogen, total phosphorus decreased Trend, the phenomenon of surface accumulation, the study area of soil C:N, C:P, N:P value of the difference in response to soil depth and soil TN, the source of the difference of TP is closely related to.N:P as important physiological parameters in the study area, in addition to alpine grassland, saline alkali soil N:P value has little change trend, the vegetation type soil the N:P value with the increase of soil depth with a serrated drop. (6) by Pearson correlation analysis, the total nitrogen content of the plant was positively correlated with soil nitrate nitrogen, carbon, phosphorus content and soil carbon, nitrogen and phosphorus content and the stoichiometric correlation was not significant. In the study of carbon nitrogen and phosphorus plant and chemical measurement and soil C:N, C:P, N:P showed no obvious correlation, in the same period of carbon nitrogen and phosphorus in plant and soil is not completely synchronous mode. (7) by stepwise regression analysis, plant OC was negatively correlated with silt and clay, TN There is negative correlation between TP and soil inorganic carbon positive relationship, the environmental factors of plant C:N, C:P, N:P value is not significantly affected, variable has not entered the regression equation. (8) by the method of stepwise regression, the main factors affecting soil SOC Qinghai Tibet Plateau pH value; factors affecting soil TN from followed by soil Alk, pH value, soil clay content; for TP, environment influence factor from big to small order of pH value of soil, elevation, Alk; the main factors affecting soil C:N value for Tibetan Plateau annual temperature; for the C:P and N:P values, the influence of the environmental factors as the clay content.

【学位授予单位】：天津师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948.1

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