不同林龄闽楠人工林生态化学计量特征研究

发布时间：2018-01-17 15:36

  本文关键词：不同林龄闽楠人工林生态化学计量特征研究　出处：《中南林业科技大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 闽楠 不同林龄 土壤 叶片 根系 生态化学计量特征

【摘要】：生态系统内C、N、P元素的化学计量比值特征,能够揭示植物生长过程中不同元素相互影响的规律,生态化学计量特征的研究日益成为全球生态系统变化研究的焦点。闽楠(Phoebe bournei(Hemsl).Yang)属国家二级保护珍稀濒危树种,资源也越来越少。如何更好地经营闽楠人工林成为学者们研究的主要方向。本文通过开展对不同林龄闽楠人工林的生态化学计量特征研究,以期能够初步了解闽楠生长发育的养分限制性情况以及土壤、叶片和根系间的协同作用,为更好地保护和培育闽楠人工林提供理论依据。本研究在永州市金洞管理区闽楠人工林中,选取下桃源(14a)、树木园(45a)、上司源(60a)三个不同林龄林分,并分别设置2块25m×25m的样地,于2016年1、4、7、10月采样四次。主要研究结果如下:(1)土壤中C、N含量表现为14a60a45a,14a和60a显著高于45a;P含量表现为45a60a14a,均无显著性差异;随着林龄的增加C:N逐渐降低,C:P和N:P先降低后升高;3个林龄土壤C含量与C:P比值、土壤N含量和N:P比值均存在极显著正相关关系(p0.01)。(2)叶片C、P含量表现为14a45a60a,N含量表现为45a14a60a;叶片C:N比值先降低后升高,C:P比值和N:P比值先升高后降低;14a叶片全N与C:N之间呈负相关关系(p0.05),45a和60a叶片全N与C:N之间呈显著负相关关系(p0.05);45a叶片全P与C:P之间关系呈负相关关系(p0.05),14a和60a叶片全P与C:P之间呈显著负相关关系(p0.05)。(3)根系C含量随着林龄的增加而增加,表现为60a45a14a,并且三者之间出现显著性差异(p0.05),N、P含量表现为14a45a60a,但无显著性差异;根系C:N、C:P和N:P比值也随着林龄的增加呈现上升的趋势;14a根系全N与C:N之间、全P与C:P之间均呈负相关关系,但未达到显著水平;45a和60a根系全N与C:N之间呈极显著负相关关系(p0.01);45a和60a根系全P与C:P之间呈显著负相关关系(p0.05)。(4)14a叶片C含量和土壤P含量之间,45a叶片N含量和土壤N含量之间存在显著负相关关系(p0.05);14a根系C元素含量与土壤P元素含量之间存在极显著正相关关系(p0.01),45a根系P元素含量与土壤C元素含量之间存在极显著负相关关系(p0.01);14a叶片各指标与根系N含量关系密切,45a叶片各指标与根系P含量关系密切,60a叶片各指标与根系C、N含量关系密切。本次研究结果表明金洞林场14a闽楠生长受到N元素的限制;45a闽楠生长受到P元素的限制;60a闽楠生长受到N、P元素的共同限制。整体来看,金洞林场闽楠叶片N:P平均值为14.39,说明该地区闽楠人工林受N和P共同限制。本次研究能够为更好的培育及经营闽楠人工林提供指导意见,为金洞林场土地的合理利用提供科学依据,为国家战略储备林建设提供数据支持。
[Abstract]:The characteristics of the stoichiometric ratios of the elements C _ (N) N _ (P) in the ecosystem can reveal the interaction of different elements in the process of plant growth. The study of ecological stoichiometry has increasingly become the focus of global ecosystem change research. It is a rare and endangered tree species protected by the state. How to better manage the plantation of South Minnan has become the main research direction of scholars. This paper carried out the study on the ecological stoichiometric characteristics of different forest ages. The aim of this study was to understand the nutrient restriction of growth and development and the synergism among soil, leaf and root system. In order to provide theoretical basis for better protection and cultivation of Minnan plantation, this study selected the lower Taoyuan (14a) and the Arboretum (45a) in Jindong management area of Yongzhou City. Three stands of different forest ages were set up with 2 plots of 25m 脳 25m on 2016. In October, we sampled four times. The main results were as follows: (1) the content of C ~ (2 +) N in soil was 14a 60a 45a 14a and 60a significantly higher than 45a; P content was 45a60a14a, there was no significant difference. With the increase of forest age, C: n decreased gradually, C: P and N: P decreased first and then increased. There was a very significant positive correlation between C content and C: P ratio, N content and N: P ratio in soil of three forest ages. The content of N was 45a14a60a; The C / N ratio of leaves first decreased and then increased, and the ratio of C: P and N: P increased first and then decreased. There was a significant negative correlation between total N and C: n in leaves for 14 years and C: n in leaves for 45 years and 60 years, respectively, and there was a significant negative correlation between total N and C: n in leaves. There was a negative correlation between total P and C: P in leaves for 45a (p 0.05). There was a significant negative correlation between total P and C: P in leaves of 14a and 60a. The root C content increased with the increase of forest age, showing 60a45a14a. There was a significant difference among the three groups, but there was no significant difference between them. The ratio of C / N: P and N: P also increased with the increase of forest age. There was a negative correlation between total N and C: n in 14a root system, and a negative correlation between total P and C: P, but no significant level. There was a very significant negative correlation between total N of root system and C: n in 45a and 60a. There was a significant negative correlation between total root P and C: P at 45a and 60a. There was a significant negative correlation between leaf C content and soil P content. There was a significant negative correlation between leaf N content and soil N content in 45a. There was a very significant positive correlation between the content of C element in root system and the content of P element in soil for 14a (p 0.01). There was a very significant negative correlation between P content in roots and C element content in soil for 45a, and there was a significant negative correlation between P element content and C element content in soil. The relationship between leaf indexes and root N content was close. Each index of leaf and root P content were closely related to the P content of root system for 45a. Each index of leaf and root system C were closely related to each index of leaf for 60 years. The results showed that the growth of Minnan was restricted by N element for 14 years in Jindong Forest Farm. The growth of Minnan was restricted by P element for 45 years. On the whole, the average value of N: P was 14.39 in the leaves of Nemenia mongolicum in Jindong Forest Farm. This study can provide guidance for better cultivation and management of the plantation, and provide scientific basis for the rational use of land in Jindong Forest Farm. To provide data support for national strategic reserve forest construction.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S792.24
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本文编号：1436882