辽东栎林蚂蚁-蚜虫互利关系的生态效应研究
文献类型：学位论文
| 作者 | 张霜 |
| 学位类别 | 博士 |
| 答辩日期 | 2012 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 马克明 |
| 关键词 | 蚂蚁-蚜虫互利 ant-aphid mutualism 蚂蚁-植物相互作用 ant-plant interactions 蜜露 honeydew 植食性昆虫 herbivore 生物防御 biotic dfense |
| 其他题名 | Ecological effects of ant-aphid mutualism in an oak (Quercus liaotungensis) forest |
| 中文摘要 | 物种间的互利关系在生态系统中具有十分重要的作用。蚂蚁-植物的相互作用近年来已经成为研究互利的生态与进化意义的模式系统之一。在这一系统中，植物能直接地或者间接地给蚂蚁提供食物或营巢空间，而蚂蚁则对植物进行保护，减少植食性昆虫对植物的伤害，二者之间形成互利关系。在蚂蚁-植物的间接作用系统中，植物通过蜜露昆虫（如蚜虫等）给蚂蚁提供食物资源，而蚂蚁则与蜜露昆虫存在直接的互利关系。蚂蚁在看护蜜露昆虫时也对植物进行保护，进而对植物起到有利影响。目前对于蚂蚁-蜜露昆虫的互利对植物的作用程度及影响因素并不清楚。 本研究以蚂蚁-蚜虫-植物三者间的相互作用为研究体系，首先通过对以往研究的meta分析，识别了蚂蚁-蚜虫的互利作用所具有的生态效应，并定量分析了其作用程度的大小和影响因素。基于meta分析的结果，在北京东灵山地区的辽东栎林中，探讨了植物大小（个体发育阶段）及实验单元的尺度对蚂蚁-蚜虫互利生态效应的影响；在较大面积内对蚂蚁进行了林冠隔离，以探讨蚂蚁-蚜虫互利关系对地面节肢动物多度的影响；并在海拔梯度上分析了蚂蚁-蚜虫的互利关系对植物以及地表节肢动物多度的影响在环境梯度（海拔）的背景下是否显著。研究发现： 1）Meta分析结果表明，蚂蚁-蜜露昆虫的互利具有多种生态效应。这种互利关系能显著降低植物遭植食性昆虫的取食程度，降低植物上植食性昆虫以及捕食者的多度同时对植物的种子传播也具不利影响。但总的来看这种互利对植物的生长和繁殖没有显著影响。进一步分析表明蚂蚁-蜜露昆虫互利的生态效应会随着气候带变化而变化。在热带与亚热带地区，其生态效应较强，在温带地区，上述效应较弱。 2）在北京东灵山地区的辽东栎林中，蚂蚁-蚜虫的互利可以显著降低辽东栎的叶片损失，降低林冠上的植食性昆虫和捕食者的多度，对植物的果实产量没有显著影响，这种互利关系的生态效应并不会随着植物的大小而变化。这说明，蚂蚁可以给种群中处于不同个体发育阶段的植物个体提供同等程度的保护。组织尺度（枝条，植株）与空间尺度（处理枝条的大小或处理植株的大小）的大小都不会对其生态效应产生显著影响。这一结果说明与理论预测和前人研究结果不同，在蚂蚁-蚜虫的互利作用中，并不存在明显的尺度效应。 3）通过在较大尺度上对林冠进行蚂蚁的隔离发现，蚂蚁-蚜虫互利关系的生态效应并不局限于林冠上，这种互利关系对地面节肢动物群落同样具有重要的影响。林冠上蚂蚁-蚜虫的互利关系破裂之后，会引起地面蚂蚁多度的降低，同时引起地面甲虫多度的升高。说明蚜虫不仅能引起林冠上蚂蚁的多度增加，同样能提高蚂蚁在地面的活动强度。林冠上的蚜虫间接的对地面甲虫多度产生了不利影响。由于本研究中的甲虫多数为捕食性步甲，所以甲虫多度的降低可能会产生进一步的营养级联效应。该研究首次将人们对蚂蚁-蚜虫互利作用的生态效应的认识从林冠扩展到了地面。 4）通过对沿海拔样带的调查发现，即使在多种生物非生物因素同时作用的情况下，与叶片自身养分含量、土壤养分状况、其它捕食者多度（甲虫，蜘蛛）以及群落结构特征相比，蚂蚁是影响辽东栎沿海拔叶损失格局的最重要因素。群落中，蚂蚁多度越高，辽东栎的叶片损失程度就越低。同时，蚂蚁的多度也是抑制群落中甲虫多度的关键因素。表明即使在影响因素复杂的群落水平上，蚂蚁-蚜虫的互利关系在林冠上（减少叶片损失）和地表（抑制甲虫多度）的生态效应仍然显著。 总之，本研究定量地探讨了蚂蚁-蚜虫的互利关系所具有各种生态效应及其影响因素。证明了蚂蚁-蚜虫互利关系的生态效应对不同个体发育阶段植物，以及在不同尺度上对植物的影响具有一致性。并首次通过控制实验和野外调查相结合的方法证明了这种互利关系对地面节肢动物群落的重要影响。其结果对于全面认识种间互利关系在群落中所发挥的生态效应具有重要意义。 |
| 英文摘要 | Mutualistic interactions have important ecological effects in community. Protective ant-plant interactions have been used as model systems in studies about the ecological effects of mutualism. In this system, plants offer foods or nesting places for ants, as reward, ants protect plants by reducing herbivory. In the indirect ant-plant interactions, ants feed on honeydews secreted by hemipteran, in return ants protect hemipteran from predators. Plants can indirectly benefit from the ant-hemipteran mutualism. But the significance of the protective effect is still unclear. In this study, we first conducted a meta-analysis on published studies about this topic to identify and quatify the ecological effects of ant-hemipteran mutualism, as well as the possible factors mediating those effects. Then based on the results of the meta-analysis, we conducted experimental and observational studies in the Donling Mountain. First, we evaluated the ecological effects of the ant-aphid mutualism on different sized oak trees of Quercus liaotungensis, the dominant species in the study area. Second, we tested the role of scale in the ecological effects of ant-aphid mutualism. Third, we excluded ants from canopy at a relatively larger scale to see the possible effects of the mutualism on the arthropod community at forest floor. At last, we explored the ecological effects of the mutualism along an elevation gradient. The results are as following: 1) Through the meta-analysis, we found that the mutualism had significant protective effects on the host plans, although those effects did not lead to enhanced plant growth or reproductive performance. Both herbivores and predators on plants were strongly suppressed by the mutualism; a similar pattern was also detected for fruit removal. The ecological effects of the mutualism tended to be more consistent and stronger in tropical and subtropical regions, whereas in temperate regions, none of the tested variables was significantly affected by the mutualism. Some of the ecological effects are also mediated by plant life form. The study confirmed that the ant-hemipteran mutualism has a wide range of ecological influences on plants and highlights the significance of a common and wide-spread mutualism. 2) We found that the impacts of ants on plants, aphids, caterpillars, and galls did not differ by the size of the tree. The aphid-tending ants Lasius fuliginosus had a significant protective effect for Q. liaotungensis, but this effect did not convert to enhanced fruit production during the 2-year study period. Considering that size can be used as an indicator of a plant’s ontogenetic stage, our results indicate that with similar densities of aphids and, in turn, ants on their canopy, trees at early and later ontogenetic stages are equally protected by the aphid-tending ants. Both organization and spatial scales had no significant effects on the outcomes of the ant-plant interaction. The effect of ants on herbivores was also not significantly impacted by scale. Contrasting to previous assumption, we found no scale effect in the outcomes of the aphids mediated indirect ant-plant interaction. 3) We found that the exclusion of ants from the canopy significantly decreased the abundance of ants on the forest floor, but increased the abundance of beetles, although the effect was only significant in the large ant-exclusion plot. The field survey showed that the abundance of both beetles and spiders was negatively related to the abundance of ants. These results suggest that aphids located in the tree canopy have indirect negative effects on beetles by enhancing the ant abundance on the forest floor. Considering that most of the beetles in our study are important predators, the ant-aphid mutualism can have further trophic cascading effects on the forest floor food web. 4) Along the elevation gradient, compared to other biotic and abiotic factors like the nutrient quality of leaves, the nutrient quality of soil, the abundances of other predators (spiders and beetles), the abundance of ants is the key factor that determine the herbivory of Q. liaotungensis. The level of herbivory decreased with the increase of ant abundance. Ant abundance is also an important factor that suppresses the abundance of beetles in community. Those results suggested that the ant-aphid mutualism has important ecological effects even in complex habitats with envrionmnental gradients. In general, those studies highlight the ecological significance of ant-aphid mutualism in community. Our results confirmed the ecological effects of the mutualism are not impacted by plant size and the scale of the experiment unit. For the first time, we proved that the ecological effects of ant-aphid mutualism are not limited to canopy but also on forest floor. We also cofirmed the ecological effects of ant-aphid mutualism in complex habitats with environmental gradients. Those findings are important for us to fully evaluate the ecologica effects of a common and wide spread mutualism in community. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/35119]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 张霜. 辽东栎林蚂蚁-蚜虫互利关系的生态效应研究[D]. 北京. 中国科学院研究生院. 2012. |
入库方式： OAI收割
来源：生态环境研究中心
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