【作者】 张灵菲；

【导师】 傅华；

【作者基本信息】 兰州大学 ， 草地植物营养学， 2013， 硕士

【摘要】 虽然生物多样性一生态系统功能关系的研究己不计其数,但关于多样性的不同成分——物种多样性、功能群多样性及功能特征多样性对生态系统功能影响的研究尚不多见。本研究利用空间序列代替时间序列的方法,在甘肃省玛曲县高寒草甸,选择弃耕后恢复1、3、7、10、15年的5个演替梯度,就高寒草甸恢复演替过程中植物多样性——物种多样性、功能群多样性及功能特征多样性与生产力的关系进行了研究。主要结果如下：1.植物种多样性随着草地恢复演替的进程发生了显著的变化。物种数目由演替第1年的9种增加到演替第15年的37种,演替与物种多样性间呈显著正相关关系。物种多样性指数则由演替第1年的0.81增加到了第15年的3.13,亦表现出显著的增加趋势,二者间呈单峰曲线关系。2.植物功能群多样性和功能群内物种数也随着演替过程呈增加趋势。功能群由一年生杂类草和禾草2个功能群增加到一年生杂类草、禾草、豆科牧草、莎草类和多年生杂类草5个功能群。演替梯度与功能群间呈显著正相关关系。对于功能群多样性指数而言,其变化幅度则大得多,由演替第一年的0.73增加到第15年的3.17,演替与功能群多样性间亦呈显著正相关关系。此外,演替过程中禾草、多年生杂类草、莎草及豆科类功能群内物种数和物种多样性指数均呈增加趋势,而一年生杂类草功能群内物种数和多样性指数则呈下降趋势。3.植物功能特征及功能特征多样性均随演替时间的延长而发生了显著变化。植株高度、相对生长率以及比叶面积等功能特征均随演替时间的延长而下降,其与演替时间均呈显著的负相关关系,而叶干物质含量则随演替时间的延长而增加,二者间呈显著的正相关关系。功能特征多样性由演替初期的0.1591增加到演替第15年的0.5424。表现为随着演替时间的延长,功能特征多样性显著增加,二者间呈显著正相关关系。4.地上净初级生产力随着演替时间的延长呈下降趋势,二者间呈显著的负相关关系。演替过程中,物种数及物种多样性指数均与净初级生产力间呈显著负相关关系；功能群多样性与净初级生产力间也呈负相关性。功能特征中株高、相对生长率、比叶面积分别与净初级生产力呈正相关关系,而叶干物质含量与净初级生产力呈负相关关系。功能特征多样性与生产力间也呈显著负相关关系。以上结果表明,高寒草甸恢复演替对植物多样性的不同成分——物种多样性、功能群多样性及功能特征多样性均产生了重要影响。随着演替时间的延长,草地群落物种多样性大为增加,草地朝着健康的方向发展。但由于物种多样性的增加、物种间对养分利用的竞争作用增强、土壤中可利用养分的限制,草地生产力则随着演替进程而下降。因此,在草地管理过程中,应采取围栏封育、适度利用的策略,以利于生物多样性的维持及生产力的恢复。更多还原

【Abstract】 Although a great deal of researches concern to relationships between biodiversity and ecosystem functioning, there is as yet no agreement as to how different components of diversity, including species diversity, functional group diversity and functional trait diversity, could influence ecosystem properties. In this study, by using a spatial sequence approach instead of a temporal one, the relationship between different components of plant diversity and aboveground primary productivity were investigated along a successional stages of restoration on the alpine meadow in Qinghai-Tibetan Plateau. The different components of diversity, including species diversity, functional group diversity and functional traits diversity, were used as diversity index. The gradients of recovery succession included1,3,5,10, and15years respectively. The main conclusions drawn from the study are as follows:1. Species diversity varied significantly with the recovery succession. Species number increased from9to37, while Shannon index increased from0.81to3.13as the succession of grassland change form1year to15years. There was a positive correlations between species number and succession and a unimodal relationship between Shannon index and succession.2. Plant functional group diversity and species number within functional groups increased with the successional gradients. Functional groups increased from2(annual forbs and grass) to5(annual forbs, grasses, legumes, sedges and perennial forbs). Functional group index varied from0.73to3.17as the grassland succession change from1year to15years. There were also positive correlations between succession and functional group number and functional group index. Besides, species number within functional group in grass, perennial forbs. sadges and legumes all increased significantly, while species number within annual forbs decreased significantly.3. Plant functional traits and functional trait diversity varied greatly along the successional gradient. Plant height, relative growth rate and specific leaf area declined significantly with the succession prolonged, leaf dry mass content, however, rose significantly. There are negative correlations between plant height, relative growth rate and specific leaf area and succession gradient, but positive correlations between leaf dry mass content and succession. Functional trait diversity increased from0.1591in the beginning of succession to0.5424in the fifteen years of succession. There also existed positive correlation between them.4. Aboveground net primary productivity decreased with succession, there was a negative correlation between them. The relationship between species number, Shannon index and productivities was negative correlated. Functional group diversity, including both functional group number and functional index, are negative correlated with productivity along the successional gradient. Among the four functional traits, plant height, relative growth rate and specific leaf area showed positive correlations with productivity. Contrast with this, leaf dry mass content showed a negative correlation with productivity. Functional trait diversity, however, showed significantly negative correlations with productivity.These results suggested that succession had an inmportant influence on different component of plant diversity——spciece diversity, functional group diversity and functional trait diversiy. As the succession progress, plant diversity increased greatly, the grassland developed more healthy. Grassland productivity, however, decreased as the succession extend because of the intensity of interspecific competition incrased and the limitation of avalable resource in soil. Therefor, in order for biodiversity protection and productivity recovering, the measures of enclosure and appropriate utilization should be adopted in the grassland management in the future.更多还原