【作者】 白荣；

【导师】 郎南军；

【作者基本信息】 昆明理工大学 ， 生态学， 2012， 硕士

【摘要】 本论文主要研究滇中高原典型植被不同演替阶段的植物叶片、根系(粗根、细根)、土壤、凋落物C、N、P、K、Ca、Mg、Na元素含量及化学计量比特征、元素间的相互关系及元素化学计量比的影响因子,判断典型植被的养分限制状况,并揭示小尺度水平上典型植被演替过程中植物特征之间的协同性趋势。通过研究得到下列结论：1.植物叶片C、Mg含量随植被演替进程先升高后降低,P、K含量随植被演替进程呈降低的趋势,N、Ca、Na含量随演替进程上下波动；叶片N、P、K、Ca、Mg间具有明显的线性关系,植物叶片元素受根系N、P、K、Na的影响较大；植物叶片C/N、N/P、Mg/Na比随植被演替进程上下波动,K/Ca、Ca/Mg比随演替进程呈下降趋势,P/K比随演替进程先升高后降低；植被演替的前初期(草地、灌丛)群落受N、P限制,演替中期(混交林)群落受N、K限制,演替后期(阔叶林)群落受P、K限制；随着植被类型的改变,植物叶片元素计量比的影响因子存在差异；各计量比间也具有一定的相关性。2.植物粗根C、N、P、Ca、Na含量随植被演替进程呈上升趋势,K、Mg含量呈下降趋势；细根N、P、Ca、Mg含量随演替进程呈上升趋势,C、K、Na含量呈下降趋势；根系自身的N、P、K元素对其它元素的含量影响较大；粗根、细根元素间的相关性存在差异；土壤P、K、Mg对植物根系元素的影响较大；植物根系C/N、P/K、Mg/Na(?)匕随植被演替进程先升高后降低,N/P、K/Ca比随演替进程先下降后升高,Ca/Mg比随演替进程上下波动；土壤元素对根系元素计量比的影响较小,根系元素计量比受自身多种元素的共同调控。3.土壤容重随植被演替进程而减小,随土层深度增加而增大；土壤孔隙度随植被演替进程而增大,随土层深度增加而减小；土壤C、N、Na含量随植被演替进程先升高后降低,K、Ca、Mg含量随演替进程总体上呈下降的趋势,P含量随植被演替进程上下波动；垂直剖面上,四种不同植被下土壤C含量随土层深度加深而降低,N含量随土层深度的加深无明显规律,P、K含量的垂直分布较均匀,Ca、Mg、Na含量随土层深度的加深呈先升高后降低的变化趋势；土壤C、P、K、Ca、Mg(?)司线性关系明显；土壤K、Mg元素有相当部分来源于凋落物的归还；土壤各计量比值随植被演替进程呈先升高后降低的变化规律；不同植被下土壤C/N比随土层的加深而降低,P/K、Ca/Mg、Mg/Na比随土层的加深呈先升高后降低的变化规律,N/P、K/Ca比随土层的加深而升高；草丛、灌草丛、针阔混交林土壤元素的计量比受其C、P、K、Ca、Mg、Na的共同调控,阔叶林土壤元素的计量比则受其C、N、P、K、Ca、Mg的影响较大。4.四种植被下,针阔混交林凋落物的储量最大,阔叶林储量次之,草丛储量最小；凋落物C、K、Ca、Mg含量随演替进程而降低,N含量随演替进程表现出先升高后降低的规律,P、Na含量随演替进程上下波动；凋落物C、K、Ca、Mg、Na间具有明显的相关性；凋落物C/N、Ca/Mg比随植被演替进程先下降后升高,N/P、K/Ca比随演替进程先升高后降低,P/K比随演替进程而升高,Mg/Na比随演替进程而降低；凋落物的计量比与其的元素具有明显的线性关系。更多还原

【Abstract】 This thesis researches the stages of succession of the typical vegetation in Yunnan Plateau on plant leaves, roots, soil, litter, the element content of C, N, P, K, Ca, Mg, Na and the stoichiometric ratio characteristics, the relationship between the research objects and the elements and the impact factors of the stoichiometric ratio, aiming at estimating the nutrient limit condition of the typical vegetation and revealing the synergistic trend among the plant characteristics during the process of typical vegetation succession in the small-scale level. The results showed that as follows:(1) The content of the leaf C and Mg showing first increases then decreases vary with the process of vegetation succession, while P, K content decreases, and N, Ca and Na content fluctuates; N, P, K, Ca and Mg content among the leaves shows obvious linear relationship, elements of plant leaves are impacted by the N, P, K and Na content in their roots greatly; the ratio of C/N, N/P, Mg/Na in the plant leaves appears fluctuation with the vegetation succession processed, the ratio of K/Ca, Ca/Mg shows downtrend with it, and the ratio of P/K first increases then decreases; at the initial phase of vegetation succession, the grass and shrub community growth are restrained by the content of N, P. At the medium time, the mixed forest community growth is restrained by the content of N, K. at the later stage, the broad-leaved forest community development is restrained by the content of P, K; with the change of vegetation type, the impact factors of the elements stoichiometric ratio in plant leaves are different; the stoichiometric ratios relates to each other.(2) the content of C, N, P, Ca, Na in plant coarse roots rises with the process of vegetation succession, and the content of K, Mg decreases; the content of N, P, Ca, Mg in plant fine roots rises with the process of vegetation succession, and the content of C, K, Na declines; the content of N, P, K in the root system itself has greater impact on the content of other elements; the correlation between coarse roots and fine roots elements differs; the content of P, K, Mg in the soil has great impact on the roots element; the content of C/N, P/K and Mg/Na of plant roots than first increases then decreases, the ratio of N/P, K/Ca first decreases then increases, the ratio of Ca/Mg fluctuates; the elements in the soil has a little influence on the root elements stoichiometric ratio, and it is jointly regulated by its own various elements.(3) The soil bulk density decreases with the vegetation succession process and increased with the soil depth; the soil porosity increases with the vegetation succession process and decreases with the soil depth; the content of C, N, Na in the soil first increases and decreases with the vegetation succession process, the content of K, Ca, Mg appears downtrend with the succession process in general, and the content of P fluctuates; on the vertical profile, the content of C in the soil under four different vegetation decreases with soil depth, while the content of N changes with no apparent rule, the content of P, K distributes uniformly in the vertical profile, the content of Ca, Mg, Na first increases then decreases with soil depth; the content of C, P, K, Ca, Mg in the soil shows obvious linear relationship; a considerable part of K, Mg element comes from the return of litter; all stoichiometric ratios in the soil first increase then decrease; under the different vegetation, the ratio of C/N decreases with soil depth, the ratio of P/K, Ca/Mg, Mg/Na first increase and then decrease with soil depth, while the ratio of N/P, K/Ca increases; the stoichiometric ratio of soil elements of grass, shrub conifer forest commonly controlled by of the content of C, P, K, Ca, Mg, Na in the soil, and the stoichiometric ratio of the soil elements in the broad-leaved forest is subject to the content of C, N, P, K, Ca, Mg.(4) as for litter reserves of four kinds of vegetation, the mixed coniferous forest has the most, broad-leaved forest takes second place, and the grass follows; in the litter, the content of C, K, Ca, Mg reduces with the succession process, the content of N first increases then decreases, the content of P and Na fluctuates in the succession process; the content of C, K, Ca, Mg, Na in the litter has significant correlation; the ratio of C/N, Ca/Mg in the litter first decreases then increases, the ratio of N/P, K/Ca is otherwise, the ratio of P/K increases, and the ratio of Mg/Na reduces; the litter stoichiometry ratio has a significant linear relationship with its elements.更多还原