| 摘要: |
| 金沙江是长江上游梯级大库富集之地,在金沙江地区选择典型水库开展植物表型可塑性和适应策略研究对该区一众水库生态治理具有重要的参考价值。本文以金沙江观音岩水库消落带为研究区,定量比较了经多年周期性水淹干扰后,绝对优势植物根茎叶性状的表型可塑性,分析了绝对优势植物应对主导因子的关键性状及其协同响应特征和权衡策略。结果表明:1)调查共记录了植物种类11科21属21种,优势度大于0.1的仅有狗牙根和苍耳,为绝对优势种。2)淹水对狗牙根和苍耳功能性状具有极显著影响,是二者功能性状变异的主导因子。3)狗牙根的株高、主茎长、分茎数量、主茎宽、叶片数量和叶面积,以及苍耳的分茎数量、叶片数量、根冠比和比叶面积的表型可塑性指数均超过0.6,是应对淹水的敏感性状。但是,狗牙根的叶片数量、叶面积以及苍耳的比叶面积对淹水的可塑性响应表现出短期时效性,为非适应性可塑性。4)淹水深度调控狗牙根在“逃避”策略和“静默”策略之间的权衡选择,并通过不同的性状组合以及地上和地下部分资源分配以协同响应。5)淹水导致狗牙根和苍耳的生态对策趋同,均采取S/SR策略。此外,相比于狗牙根为水库消落带的普遍推荐种,苍耳因其存在水质污染风险而褒贬不一,但苍耳具有重要的药用价值,能否在每次淹水来临前进行刈割值得进一步探讨。 |
| 关键词: 功能性状 表型可塑性指数 绝对优势种 生态策略 消落带 |
| DOI：10.18307/2024.0137 |
| 分类号: |
| 基金项目:国家自然科学基金项目(42101375,52078195)和国家自然科学基金联合基金重点项目(U22A20232)联合资助。 |
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| Phenotypic plasticity and adaptation strategies of dominant plants in the water-level-fluctuating zone of Guanyinyan Reservoir, Jinsha River |
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Jiang Weiwei1,2, Zha Zixia1, Xiao Henglin1,2
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1.School of Civil and Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, P.R. China;2.Key Laboratory of Intelligent Perception and Ecological Restoration of River and Lake Health, Ministry of Education, Wuhan 430068, P.R. China
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| Abstract: |
| The Jinsha River is rich in cascade reservoirs in the upper reaches of the Yangtze River. The selection of typical reservoirs in the Jinsha River area to carry out research on plant phenotypic plasticity and adaptation strategies has important reference value for the ecological management of reservoirs in this area. In this study, the riparian zone of Guanyinyan Reservoir in Jinsha River was taken as the study area. The phenotypic plasticity of root, stem and leaf traits of absolute dominant plants after years of periodic flooding disturbance was quantitatively compared, and the key traits of absolute dominant plants in response to dominant factors and their synergistic response characteristics and trade-off strategies were analyzed. The results showed that: 1) A total of 21 plant species belonging to 21 genera and 11 families were recorded. Only Cynodon dactylon (C. dactylon) and Xanthium sibiricum (X. sibiricum) were the absolute dominant species with dominance greater than 0.1. 2) Flooding had significant effect on the functional traits of C. dactylon and X. sibiricum. It was identified as the dominant factor contributing to the variation in functional traits of both species. 3) The plasticity index of plant height, main stem length, branch number, main stem width, leaf number and leaf area of C. dactylon and branch number, leaf number, root shoot ratio and specific leaf area of X. sibiricum exceeded 0.6, which were sensitivity traits to cope with flooding. However, the leaf number, leaf area of C. dactylon and the specific leaf area of X. sibiricum showed short-term timeliness in response to flooding, and they were non-adaptive plasticity. 4) Flooding depth regulated the trade-off between the 'escape' strategy and the 'silence' strategy of C. dactylon, and responding synergistically through different trait combinations and the allocation of aboveground and underground resources. 5) Flooding led to the convergence of ecological strategies of C. dactylon and X. sibiricum, and both adopted S/SR strategy. In addition, compared with C. dactylon, which is a commonly recommended species in the water-level-fluctuating zone of the reservoir, X. sibiricum has different opinions due to its risk of water pollution. However, X. sibiricum has important medicinal value, so mowing before each flooding is a consideration. |
| Key words: Functional traits phenotypic plasticity index absolute dominant species adaptation strategy water-level-fluctuating zone |
