| 三峡水库消落区植物群落结构及其季节性变化规律 |
| Plant Community Structure and Seasonal Variation in the Water Level Fluctuation Zone of Three Gorges Reservoir |
| 投稿时间：2019-11-13 修订日期：2020-12-01 |
| DOI：10.15928/j.1674-3075.2020.06.005 |
| 中文关键词:三峡水库 消落区 植物群落 优势种 适应机制 |
| 英文关键词:Three Gorges Reservoir water level fluctuation zone (WLFZ) plant community dominant species adaptive mechanism |
| 基金项目:国家重大研发计划（2016YFC0502208）；国家自然科学基金面上项目（51679154）；重庆市技术创新与应用示范项目（cstc2018jszx-zdyfxmX0021） |
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| 中文摘要: |
| 为探究三峡水库消落区出露期间植物群落结构的季节性变化规律，于2017年4月、6月和8月，设置了15个调查样地，根据高程将消落区分为145~155 m、156~165 m和166~175 m共3个区域，并设置未水淹区域（高程176~185 m）为对照。结果表明，消落区出露时间显著影响植物群落组成，随着出露时间的延长，群落优势种及其优势度变化规律因植物的生活型不同呈现出相反的变化规律。从4月至8月，优势植物狗牙根、牛鞭草、喜旱莲子草等多年生草本植物优势度下降，鬼针草、苍耳、醴肠、水蓼、野胡萝卜、狗尾草等一年生草本植物优势度增加；而未水淹区植物优势种及其优势度变化规律不会因生活型不同而表现出不同的规律，不同地点的植物群落优势种差异较大，相对来说艾蒿较为优势，其次为小飞蓬。高程也是影响植物群落特征的主要因子，植物群落Shannon-Wiener指数、Margalef指数、Simpson指数、植物高度均值显著低于未水淹区域；随着高程的增加，生物多样性指数及植物高度均值呈增加趋势。植物内在的适应机制，包括植物本身的冬季耐水淹能力、夏季抗旱能力、抗病虫害能力及其繁殖对策、种源扩散对策等是影响植物群落分布的主因；而外界环境条件，包括消落区土层厚度、地形坡度、土壤基质氮磷等营养盐以及受水淹持续时间、水淹深度、高程、消落区出露时间等是其主要驱动因子。 |
| 英文摘要: |
| The ecological problems in the water level fluctuation zone (WLFZ) of Three George Reservoir have attracted much attention in relevant departments of both the national and local government. As of 2017, the vegetation in the WLFZ had undergone eight wet-dry cycles. The objectives of this study were to characterize seasonal variation of the WLFZ plant community and to analyze the internal adaptive mechanisms and external environmental factors affecting plant growth. Our study will provide data to support ecological restoration and advance the WLFZ theory of large-scale reservoirs. In April, June and August 2017, samples were collected from a total of 174 plots from 15 sites along three WLFZ elevation gradients (145-155 m, 156-165 m, 166-175 m), and within an un-flooded area (176-185 m), set as the control. The height, coverage and the above ground biomass of the plants were measured in situ. Results show that the dominant species and their dominance in the plant community presented different rules with increased exposure time and were closely related to the different plant life forms. From April to August, dominance by perennial herbs (Cynodon dactylon, Hemarthria altissima and Alternanthera philoxeroides) decreased, while dominance by annual herbs (Bidens pilosa, Xanthium sibiricum, Eclipta prostrata, Polygonum hydropiper, Daucus carota and Setaria viridis) increased. The dominant species composition and their plant community dominance in the un-flooded area did not display any relation with plant life form. The dominant species of plant community in the un-flooded area was obvious different among the different sampling sites, with relative higher dominance by Artemisia argyi and Comnyza canadensis. Elevation was also a major factor affecting plant community characteristics. The mean value of Shannon Wiener diversity index, Margalef richness index, Simpson index and plant height of the WLFZ plant community increased with elevation and were significantly lower than those in the un-flooded area. The primary internal adaptation mechanisms of WLFZ plants included flood tolerance in winter, drought resistance in summer, resistance to disease and insects, plant propagation strategy and provenance diffusion strategy. The primary external environmental factors affecting the WLFZ plant community were soil depth, terrain slope, nitrogen, phosphorus and other soil nutrients, duration and depth of flooding, elevation and exposure time. |
| 张志永,胡晓红,向 林,邹 曦,史 方,李 怡,胡 莲.2020.三峡水库消落区植物群落结构及其季节性变化规律[J].水生态学杂志,41(6):37-45. |
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