美国波特兰州立大学潘仰东教授应邀到我校报告的通知
报告时间：2023年7月3日，下午15:00-18:00
报告地点：南阳师范学院东区水环院三楼会议室(现场）
腾讯会议号：893654984 （线上）
报告题目：河流恢复：重新连接一条河流通道至河漫滩
Stream restoration: Reconnecting a Stream Channel to its Floodplain
报告专家：波特兰州立大学 潘仰东 教授
报告提纲：
山间溪流具有宝贵的生态系统服务功能，但它容易受人为干扰的影响。河流恢复是指恢复河流失去的水文形态和生态系统进程的过程。在这项研究中，我们研究了美国俄勒冈州三个河流河段恢复的生物响应。“控制”区河段为未恢复河流河段，“过渡”区河段为最近恢复河流河段，“恢复”区河段是12年前通过将河道连接到其历史漫滩而恢复的河流河段。非度量多维尺度显示，底栖硅藻物种组成沿一条轴线从控制区向过渡区和恢复区河段转移。在控制区河段内，微小扁突藻、斑球藻、菱形扁突藻和小扁突藻占硅藻群落的主导地位，占所有硅藻类群的69%。然而，在恢复河段中，肘状针杆藻（21%）、细端菱形藻（10%）、短菱形藻（8%）和密集齿面体（8%）是优势藻类群。从控制区到恢复区河段，具有固氮蓝藻共生特性和低氮硅藻类群的百分比下降。此外，恢复河段河流生物群落和河岸植被叶片的d15N值系统性地高于对照河段。恢复河段改良的水文形态过程可能会增加有机物滞留和底栖活性，从而提高养分的可用性和初级生产力。这些变化可能对恢复河段的高营养级生物和河岸植被产生自下而上的影响。使用d15N值表征食物网的基本结构（硅藻物种组成）和营养相互作用，有助于更好地评估河流恢复对生态系统过程的影响。
Mountain streams offer valuable ecosystem services, but they are vulnerable to anthropogenic disturbance. Stream restoration is a process that aims to restore lost hydro-morphological and ecosystem processes. In this study, we examined biological responses to restoration of three stream reaches in Whychus Creek, Oregon (USA). The “control” was not restored, the “transition” reach was restored relatively recently, and the “restored '' reach was restored 12 years ago by reconnecting stream channels to their historic floodplains. Non-metric multidimensional scaling showed that benthic diatom species composition shifted along an axis from the control to the transition and restored reaches. In the control reach, Achnanthidium minutissimum, Cocconeis placentula, Gomphonema rhombicum and G. pumulum dominated the diatom assemblages, making up 69% of all diatom taxa. However, in the restored reach, Synedra ulna (21%), Nitzschia dissipata (10%), Rhoicosphenia abbreviata (8%) and G. olivaceoides var. densestriata (8%) were the dominant taxa. The percentage of diatoms with nitrogen (N)-fixing cyanobacterial endosymbionts and % of low N taxa decreased from the control to the restored reach. Additionally, d15N values of in-stream biota and riparian vegetation leaves were systematically higher in the restored reach compared to the control reach. Modified hydromorphological processes in the restored reach may have increased organic matter retention and hyporheic activities, subsequently enhancing nutrient availability and primary productivity. These changes could have bottom-up effects on the higher trophic level organisms and riparian vegetation in the restored stream reach. Characterizing the food-web basal structure (diatom species composition) and trophic interactions using d15N values could aid in a better assessment of the effects of stream restoration on ecosystem processes.
报告联系人：
李玉英 教授，15938462454
刘 韩 博士，18171269137
专家简介：
Dr. Yangdong Pan
潘仰东博士是美国俄勒冈州波特兰州立大学环境科学与管理学教授（1996年至今）。主要研究方向：淡水生态与管理，主要利用藻类组合来监测和评估淡水生态系统中的生态风险。近期，与从事环境方面的专业人员合作，参与了中国国际科技合作计划“九寨沟国家公园水安全和生态风险评估”等多个项目。
Dr. Yangdong Pan has been a professor of Environmental Science and Management at Portland State University, Oregon, USA, since 1996. His research centers on freshwater ecology and management. Specifically he uses algal assemblages to monitor and assess ecological risk in freshwater ecosystems. Recently, he has been collaborating with Chinese environmental professionals in several projects including water security and ecological risk assessment in the Jiuzhaigou National Park sponsored by the International Science & Technology Cooperation Program of China.
E-mail: pany@pdx.edu
南水北调中线水源区流域生态安全高等学校学科创新引智基地
2023.06.09
