CERIS, Civil Engineering Research and Innovation for Sustainability, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Natural Resources Department, Universidad Politécnica de Madrid (UPM), Calle José Antonio Novais, 10, 28040 Madrid, Spain.
Sci Total Environ. 2022 Jul 10;829:154451. doi: 10.1016/j.scitotenv.2022.154451. Epub 2022 Mar 9.
Hydropeaking is part of hydropower production. The discontinuous release of turbined water during hydropeaking generates sudden rise and falls of the water levels, as well as extended droughts. These artificial flow fluctuations impose challenging growing conditions for riverine vegetation. In order to identify vulnerable/resistant plant species to hydropeaking and to evaluate the impact of contrasting hydropeaking scenarios (simplified (i.e., sudden deep floods, frequent soil saturation and drought) and real-life, power plant-induced scenarios), we measured germination, survival, and morphological and physiological attributes of a selection of 14 plant species commonly found along riparian areas. Species were subject to different hydropeaking scenarios during three months (vegetative period) in the field and in a greenhouse. Half of the species performed worse under hydropeaking in comparison to the control (e.g., less germination and biomass, lower growth rates, reduced stem and root length, physiological stress) but none of the tested hydropeaking scenarios was clearly more disruptive than others. Betula pubescens, Alnus incana and Filipendula ulmifolia showed the largest vulnerability to hydropeaking, while other species (e.g., Carex acuta) were resistant to it. Both in the field and in the greenhouse, plants in perturbed scenarios accumulated more C than in the control scenario indicating limited capacity to perform C isotope discrimination and evidencing plant physiological stress. The highest C abundances were found under drought or flooding conditions in the greenhouse, and under the highest hydropeaking intensities in the field (e.g., Betula pubescens). Our results suggest that any hydropeaking scheme can be equally detrimental in terms of plant performance. Hydropeaking schemes that combine periods of severe drought with long and frequent flooding episodes may create a hostile environment for riverine species. Further research on "hydropeaking-tolerant" plant traits is key to draw the boundaries beyond which riverine species can germinate, grow and complete their life cycle under hydropeaking.
涌水是水力发电的一部分。涌水期间涡轮机放水的不连续释放会导致水位的突然上升和下降，以及延长的干旱。这些人为的水流波动给河流植被带来了具有挑战性的生长条件。为了确定对涌水敏感/耐受的植物物种，并评估不同涌水情景（简化情景，即突然的深洪水、频繁的土壤饱和和干旱，以及实际的、由发电站引起的情景）的影响，我们测量了沿河岸地区常见的 14 种植物物种的发芽、存活以及形态和生理特征。在野外和温室中，将物种置于三个月的不同涌水情景下（营养期）。与对照相比，一半的物种在涌水条件下表现更差（例如，发芽率和生物量更低，生长速度更慢，茎和根长降低，生理压力更大），但没有任何一种测试的涌水情景明显比其他情景更具破坏性。欧洲山桦、欧洲赤松和欧洲水杨梅对涌水最为敏感，而其他物种（如尖叶薹草）则具有抗涌水能力。无论是在野外还是在温室中，受干扰情景下的植物积累的 C 比对照情景下的更多，这表明它们进行 C 同位素分馏的能力有限，并表明植物生理压力。在温室中，干旱或洪水条件下的 C 丰度最高，而在野外，涌水强度最高时（如欧洲山桦）的 C 丰度最高。我们的结果表明，任何涌水方案在植物性能方面都可能同样具有破坏性。将严重干旱与长时间频繁的洪水相结合的涌水方案可能会为河流物种创造一个恶劣的环境。进一步研究“耐受涌水”的植物特征是确定河流物种在涌水条件下能够发芽、生长和完成其生命周期的边界的关键。
