典型草原三种主要优势种竞争研究

发布时间：2018-02-24 08:38

本文关键词： 羊草克氏针茅糙隐子草种内竞争种间竞争竞争耗能　出处：《内蒙古大学》2015年硕士论文　论文类型：学位论文

【摘要】：竞争作用的存在使得自然界中植物的形态、生活史都处于一个动态变化的过程中,从而导致整个群落结构也发生着变化。竞争被分为种间竞争和种内竞争,其中种间竞争是导致植被演替和群落构成的主要原因之一,因此,研究和探讨典型草原优势种的竞争关系对草原退化及发展趋势具有重要的意义。本文对锡林浩特毛登牧场3种主要优势种进行野外去除试验与室内控制试验,利用去除法在野外条件设置羊草、克氏针茅、糙隐子草三种优势种单生与混生样方,并对其高度、分蘖、生物量、进行测量记录及竞争耗能的计算。在室内对羊草与克氏针茅进行因素控制试验,利用响应面法对不同混种比例、水分、密度条件下二者生长指标(包括高度、分蘖数、生物量)及竞争耗能进行研究分析。研究结果如下：(1)自然条件下,羊草单生高、分株数、生物量均小于混生状态,而克氏针茅和糙隐子草单生状态3项指标均大于混生,且糙隐子草受到的竞争作用最强,耗能最多。(2)在低水分条件时,克氏针茅耐旱性强于羊草,因此干旱条件对克氏针茅生长影响相对较小,而对羊草影响较大；高水分时利于羊草生长,而对克氏针茅则不利。(3)羊草在高密度环境,占有较大比例时受到种内竞争作用较强,而克氏针茅在高密度群落中若占有较大比例时,受到种内竞争作用相对较小；在低密度时二者均能良好生长。(4)在群落中优先占有较大比例者,会最终成为优胜者,但由于种内竞争和种间竞争的相互作用,又会使群落能够保持相对稳定状态。(5)羊草与克氏针茅等比混种,羊草耗能最少,以2：8混种,克氏针茅耗能最少；不同时期羊草与克氏针茅固定能量用于生长的能力有所不同,且二者正好相反,即羊草在结实期固定能量最多,而克氏针茅结实期固定能量最少,干枯期固定能量最多。到生长末期,羊草与克氏针茅耗能均增加。探讨典型草原群落优势种之间的竞争关系,将有助于了解草原群落退化及演替的机制,同时也可预测草原群落未来的发展趋势,从而为保护草原生态平衡和合理利用草地提供科学依据。
[Abstract]:The existence of competition makes the form and life history of plants in nature in a dynamic process, which leads to the change of the whole community structure. Competition is divided into interspecific competition and intraspecific competition. Among them, interspecific competition is one of the main causes of vegetation succession and community composition. It is of great significance to study and discuss the competitive relationship of typical dominant grassland species for grassland degradation and development trend. In this paper, the field removal experiments and indoor control tests were carried out on three main dominant species in Maoden pasture of Xilinhaote. Three dominant species of Leymus chinensis, Stipa krsinensis and Cryptophagus strigella were set up in the field by the removal method, and their height, tiller and biomass were determined. The factors of Leymus chinensis and Stipa Kirschsoni were controlled by the method of response surface. The growth indexes (including height, tiller number) were measured by response surface method under the conditions of different mix proportion, moisture and density. The results were as follows: 1) under natural conditions, the single height, the number of ramet and the biomass of Leymus chinensis were all smaller than those of mixed species, while the three indexes of single growth of Stipa krjabini and Cryptophagus strigella were all higher than that of mixed species. In low water condition, the drought tolerance of Stipa krjabini is stronger than that of Leymus chinensis, so drought condition has relatively little effect on the growth of Stipa krjabini, but it has greater effect on Leymus chinensis. When water is high, it is beneficial to the growth of Leymus chinensis, but it is unfavorable to the growth of Stipa krjabini. (3) Leymus chinensis is more competitive in the high density environment, and when it occupies a larger proportion in the high density community, The relatively small effect of intraspecific competition; at low density, both of them could grow well. (4) those who preferentially occupied a larger proportion of the community would eventually become winners, but because of the interaction of intraspecific and interspecific competition, It will also keep the community in a relatively stable state. (5) Leymus chinensis and Stipa krjabini have the least energy consumption, and the energy consumption of Stipa krsini with 2: 8 hybrids is the least, and the ability of fixed energy between Leymus chinensis and Stipa Kirschsoni is different in different periods. And the opposite is true, that is, the fixed energy of Leymus chinensis is the most during the fruiting period, but the fixed energy is the least in the fruiting stage of Stipa Kirschsoni, and the fixed energy is the most in the dry period. The energy consumption of Leymus chinensis and Stipa Kirschsoni are both increased. It is helpful to understand the mechanism of grassland community degradation and succession and to predict the future development trend of grassland community by studying the competitive relationship between dominant species of typical grassland community. Therefore, it provides scientific basis for protecting grassland ecological balance and making rational use of grassland.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

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