DataSheet1_Free and underfit-scavenger river dynamics dominate the large Amazonian Pacaya-Samiria wetland structure.PDF

The Peruvian Amazon is known for harboring the greatest biodiversity on the planet, with a world record for biodiversity per unit area. Previous studies suggested that the high ecological value depends on correlations between ecosystem functionality and seasonal inundation control vegetation patches. However, the knowledge on how river morphodynamics and its complex erosion-depositional processes influence the aquatic mosaic and fishing activity in the region is still incipient. This study examines the hydrogeomorphology of the Peruvian tropical wetland of Pacaya Samiria, located in Western Amazonia, and its role in the distribution of aquatic habitats. By using remote sensing techniques, the hydrogeomorphological connectivity that bounds the Pacaya Samiria National Reserve is characterized by ancient to modern river processes. Additionally, river signatures developed by the Ucayali, Marañon, Huallaga, Pacaya, and Samiria Rivers overlap with fish extraction and dominant vegetation to describe how geomorphology is associated with the spatial distribution of fishing zones. Results indicated that paleochannels regulate wetland drainage within the Ucamara Depression, supporting stational water stagnation, vegetation cover, and formation of carbon rich detritus, relevant aspects to understand fish traits. Moreover, the Ucayali River dominates river dynamics in the Pacaya Samiria wetland, thus playing a pivotal role in shaping the complexity of streams and lakes. Furthermore, underfit-scavenger meandering rivers are observed in areas where paleochannels from large rivers are found. A geomorphological characterization of drainage patterns in freshwater environments, such as Amazonian wetlands, is crucial to develop sound management strategies. This methodological approach is expected to support decision-making in conservation actions in Amazonian environments based on understanding wetland connectivity and hydrogeomorphological behavior and their influence on commercial fisheries.

秘鲁亚马逊地区因其拥有地球上最高的生物多样性而闻名，单位面积内的生物多样性记录更是世界之最。既往研究指出，其高生态价值依赖于生态系统功能与季节性洪水控制植被斑块之间的相关性。然而，关于河流地貌动力学及其复杂的侵蚀-沉积过程如何影响该区域的水生景观和渔业活动的知识仍处于起步阶段。本研究旨在探讨位于亚马逊西部地区的帕卡亚萨米里亚热带湿地的水文学与地貌学特征，以及其在水生生境分布中的作用。通过运用遥感技术，帕卡亚萨米里亚国家公园边界的水文学与地貌学连通性被描绘为从古至今的河流过程。此外，乌卡亚利河、马拉尼翁河、乌阿利亚加河、帕卡亚河和萨米里亚河形成的河流特征与渔业捕捞和优势植被重叠，描述了地貌学如何与渔业区域的时空分布相关联。研究结果表明，古河道调节乌卡马拉凹地内的湿地排水，支持了停滞的水体、植被覆盖和富含碳的碎屑的形成，这些是理解鱼类特性的重要方面。此外，乌卡亚利河在帕卡亚萨米里亚湿地中主导了河流动力学，因此，在塑造溪流和湖泊的复杂性方面发挥着关键作用。更进一步，观察到在大型河流的古河道发现地区存在欠拟合-觅食型蜿蜒河流。对淡水环境（如亚马逊湿地）的排水模式进行地貌学特征描述对于制定合理的管理策略至关重要。此方法论预期将支持基于对湿地连通性和水文学与地貌学行为及其对商业渔业影响的了解，在亚马逊环境中的保护决策。