New records of the invasive macrophyte, Urochloa arrecta extend its range to eastern Brazilian Amazon altered freshwater ecosystems

ABSTRACT Invasive species influence the structure and functioning of ecosystems, as they affect native species, significantly decreasing their diversity. Aquatic ecosystems harbor a great biodiversity, and invasive macrophytes significantly affect the native plant communities, causing a cascade effect on other trophic levels. Among invasive macrophytes, Urochloa arrecta is cause for concern in the Neotropics and is found in several regions of Brazil, specially in the southeastern and southern regions. So far the species had been recorded only in the northern state of Amazonas. We report the first record of the species in the state of Pará, in the eastern Brazilian Amazon. We emphasize that identifying sites where this species is invasive is the best strategy to prevent its spread, aiming at the protection and conservation of Amazonian freshwater ecosystems.

摘要 外来入侵物种（Invasive Species）会影响生态系统的结构与功能，通过危害本地物种显著降低其生物多样性。水生生态系统孕育着极为丰富的生物多样性，入侵大型水生植物（Invasive Macrophytes）会显著干扰本地植物群落，进而对其他营养级产生级联效应。在入侵大型水生植物中，直立臂形草（Urochloa arrecta）在新热带区（Neotropics）备受关注，目前已在巴西多个区域被发现，尤以东南部和南部地区分布广泛。截至目前，该物种仅在巴西北部的亚马孙州有分布记录。本研究首次报道了该物种在巴西亚马孙东部帕拉州的分布记录。我们强调，明确该物种的入侵位点是遏制其扩散的最优策略，旨在保护与保育亚马孙淡水生态系统。