|Alternative Title||The Relationship between Phenological Pattern and Ecosystem Function in Natural Steppe Community
|Thesis Advisor||王 刚
|Place of Conferral||兰州
1、时间生态位互补导致的资源利用效率提高是自然草地群落中生产力随多样性增加而提高的重要机制。2、在内蒙古针茅草原群落中，物种丰富度和均匀度的增加都可以导致时间生态位的分化程度的提高。3、在植物群落中，对于物种多样性和初级生产力之间的关系而言，生长季内单次取样策略因为没有考虑时间生态位的互补， 将会导致对生态位互补效应的低估。多次取样策略可能对于物候模式明显的群落更加合理。4、物种多样性对生产力的贡献程度在不同的演替阶段不同，随着围封时间的增加表现为先减速上升而后下降的单峰曲线模式， 这表明随着时间的推移物种多样性对生产力的作用机制产生了转换。5、对于以群落生物量季节波动来表示的稳定性而言，物种多样性增加并不能导致稳定性增加，主要物种之间的作用倾向于正相关和不相关。相对而言，环境因子的作用可能更加重要。6、物种多样性对于生产力和稳定性的作用机制并不相同，超产和稳定性之间并不必然存在联系。7、相对于群落生物量季节波动表示的稳定性而言，物候互补导致的超产年际之间的变动随着物种多样性的增加而趋向稳定。
Human activities are triggering some of the most rapid species extinctions in global scale. These changes in biodiversity have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Whether there is a point at which changes in properties might adversely influence human welfare is a major issue of ecologist. In spite of many efforts, however, there remain important
aspects that are still not well understood.
There has been substantial debate within the ecological community on the interpretation of some recent research and whether the findings from these studies are as important as other factors that are well known to correlate with ecosystem functioning in nature. Based on the reviews of researches, we generalized the recent advances and controversies on biodiversity and ecosystem function. A three years experiment was conducted within Inner Mongolia steppe. Natural Steppe community was degraded because of have grazing. We investigated the relationships between biodiversity, primary production and ecosystem stability during the period of restoration. We focused on the influences of temporal niche partition, sampling strategy and the time of restoration on the relationship between biodiversity and ecosystem function. Major conclusions are as bolw.
1.High resource use efficiency caused by temporal niche complementarity is an important underling mechanism of the positive relationship between species diversity and primary production in natural grassland community.2. Increasing both species richness and species evenness would lead to a high degree of temporal niche partition in Inner Mongolia steppe.3. For the relationship of species diversity and primary production, single sampling strategy within growing season would lead to underestimated of complementarity effect because of neglect of temporal niche complementarity in plant communities. Multi-sampling strategy would be more reasonable in communities with phenological pattern.4. The effect of diversity on primary production differs in different restoration stage. The unimodal pattern indicates there has turnover on the underling mechanism.5. Measured by variation of community biomass, stability was not related to species diversity. The correlations between major component species were positive or none. Abiotic factors may have more effects than biotic factors.6. The underling mechanism of species diversity on primary production and ecosystem stability was different. There is no correlation between overyielding and community biomass stability.7. Contrast to community biomass stability, overyielding effect is more stable in higher diversity level between years.
赵亮. 草地群落物候分化模式 与生态系统功能关系研究[D]. 兰州. 兰州大学,2006.
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