C4 herbs dominate the reservoir flood area of the Three Gorges Reservoir
C4 herbs dominate the reservoir flood area of the Three Gorges Reservoir
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三峡水库库区洪泛区C4药材占主导地位
DOI：
10.1016/j.scitotenv.2020.142479
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发表时间：
2021
影响因子：
9.8
通讯作者：
Zongqiang Xie
中科院分区：
文献类型：
--
作者：
Aiying Zhang;Zongqiang Xie
水坝的运作会使河岸植被严重退化。为了改善水库河岸植被的恢复实践，重要的是要了解哪些以及如何在这种类型的生态系统中的优势种的生理和生态保持高适合度。以三峡库区库洪区为研究对象，探讨了库洪区河岸植物在长期洪-旱-洪循环过程中的组成变化。结果表明，三峡大坝截流前（2006年以前，即天然河岸带），研究区共有维管束植物769种，隶属于122科415属。筑坝后（2008-2018年），植物物种多样性迅速下降，2018年仅发现51种（22科45属）。筑坝前，研究区为多年生草本、一年生草本和灌木群落。筑坝后，灌木所占比例明显下降，一年生植物占总植物的比例增加了20%。外来入侵物种比例从5%上升到18%。值得注意的是，C4物种的比例从7%显著增加到31%。自2015年以来，RFA中的16种优势物种中有10种是C4禾本科物种。研究表明，大坝建设会造成河岸植物多样性的严重丧失，并引起外来物种的入侵。此外，C4草药将主导RFA。较高的光合速率可以帮助C4植物更快地生长，以科普RFA中氮素缺乏和生长周期短的问题。因此，筛选C4草本植物植被恢复可能有助于维持生物多样性和生态系统功能的洪-旱-洪水库洪水区。
Dam operations can dramatically degenerate riparian vegetation. To improve the restoration practices of reservoir riparian vegetation, it is important to understand which and how a dominant species physiologically and ecologically maintain high fitness in this type of ecosystems. We explored the compositional change of riparian plants during the long-term flood-dry-flood cycle in the reservoir flood area (RFA) of the Three Gorges Reservoir Area (TGRA), China. In total 769 vascular plant species (belonging to 415 genera in 122 families) existed in the study area before damming (prior to 2006, i.e. the natural riparian zone). Following damming (2008–2018), plant species diversity rapidly declined, with only 51 species identified in 2018 (45 genera in 22 families). Before damming, perennial herbs, annual herbs and shrubs co-dominated the study area. After damming, the proportion of shrubs decreased significantly, and the proportion of annuals to total plants increased by 20%. Alien invasive species proportion increased from 5% to 18%. Notably, the proportion of C4species increased significantly from 7% to 31%. Ten of the 16 dominant species in RFA since 2015 were C4Poaceae species. Our study indicates that dam construction could cause severe biodiversity loss of riparian plants and draw alien species invasion. Besides, C4herbs would dominate the RFA. A higher photosynthetic rate could help C4plants grow faster to cope with the nitrogen deficiency and short growth cycles in RFA. Hence, screening C4herbs for vegetation restoration might aid in maintaining biodiversity and ecosystem functions in flood-dry-flood reservoir flood areas.