摘要
河流生态健康评价是保护河流生物多样性、遏制河流水环境恶化趋势的前提,为探究雅鲁藏布江中游河流生态系统健康状态及其对水环境因子响应机制,于2021年的7月和10月在雅鲁藏布江中游进行浮游植物样品的采集和水环境因子的测定,鉴定浮游植物物种并计算其细胞丰度和生物量,构建浮游植物完整性指数评价该河段河流生态健康状态,分析水环境因子和浮游植物群落时空分布特征、 P-IBI值和群落参数与水环境因子的相关性.结果表明,水环境因子在时间上差异不明显,在空间上有显著的差异;浮游植物平均细胞丰度和平均生物量大小为:丰水期>枯水期以及干流>支流,硅藻在群落中占绝对优势,pH和WT是驱动浮游植物时空分布的主要水环境因子;雅鲁藏布江中游生态健康状态整体为“健康-亚健康”,河流健康状态枯水期优于丰水期、支流优于干流,EC、 TUR、 WT、 NO^(-)_(3)-N和NH^(+)_(4)-N是影响该河段生态健康状态的主要水环境因子,可通过影响水体中浮游植物群落演替的方向和速率,参与和影响河流生态系统的物质循环和能量流动过程,驱动了雅鲁藏布江中游河流生态健康状态.
River ecological health assessments are the premise for protecting river biodiversity and curbing river water environment deterioration.To explore the river ecosystem health status and its response mechanism to water environmental factors in the middle reaches of the Yarlung Zangbo River,phytoplankton samples were collected during July and October 2021,and water environmental factors were measured.The phytoplankton species were identified,and their cell abundance and biomass were calculated.The phytoplankton integrity index was constructed to evaluate the ecological health status of the river.The temporal and spatial distribution characteristics of water environmental factors and phytoplankton community,as well as the correlation between P⁃IBI value and community parameters and water environmental factors were analyzed.The results showed that the difference in water environmental factors was not evident in time but was significant in space.The average cell abundance and biomass of phytoplankton were in the order of wet season>dry season and main stream>tributaries.Diatoms dominated the community,and pH and WT were the major water environmental factors driving the spatial and temporal distributions of phytoplankton.The ecological health status of the middle reaches of the Yarlung Zangbo River was“healthy to sub⁃healthy.”The river health status was better than that of the dry season,and that of the tributaries was better than that of the main stream.EC,TUR,WT,NO^(-)_(3)⁃N,and NH^(+)_(4)⁃N were the major water environmental factors affecting the ecological health status of the river reach,which could be affected by the direction and rate of phytoplankton community succession.It is involved in and affects the process of material circulation and energy flow of the river ecosystem,thereby driving the ecological health of the middle reaches of the Yarlung Zangbo River.
作者
李晓东
杨清
刘惠秋
巢欣
杨胜娴
巴桑
LI Xiao-dong;YANG Qing;LIU Hui-qiu;CHAO Xin;YANG Sheng-xian;BA Sang(Earth's Third Pole Carbon Neutralization Research Center,Tibet University,Lhasa 850000,China;Laboratory of Qinghai-Tibet Plateau Wetland and Watershed Ecosystem,School of Science,Tibet University,Lhasa 850000,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第9期4941-4953,共13页
Environmental Science
基金
国家自然科学基金项目(32070418)
2022年中央财政支持地方高校改革发展专项(藏财预指〔2022〕1号)。
关键词
河流生态健康
生物完整性指数
水环境因子
浮游植物
雅鲁藏布江中游
river ecological health
index of biotic integrity
water environment factor
phytoplankton
middle reaches of the Yarlung Zangbo River
