Programa de Pós-Graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, 69067-375, Brasil.
Faculdade de Ciências Agrárias, Universidade Federal do Amazonas, Manaus, Amazonas, 69077-000, Brasil.
Sci Rep. 2017 Jan 10;7:40170. doi: 10.1038/srep40170.
Combined effects of climate change and deforestation have altered precipitation patterns in the Amazon. This has led to changes in the frequency of extreme events of flood and drought in recent decades and in the magnitude of the annual flood pulse, a phenomenon that influences virtually all aspects of river-floodplain ecosystem dynamics. Analysis of long-term data revealed abrupt and synchronous changes in hydrology and fish assemblage structure of a floodplain lake near the confluence of Amazon and Negro rivers. After an intense drought in 2005, the assemblage assumed a different and fairly persistent taxonomic composition and functional structure. Declines in abundance after 2005 were more pronounced for species of all sizes having equilibrium life history strategy, large species with periodic life history strategy, and for all trophic levels except primary consumers. Our results suggest that the extreme drought triggered changes in the fish assemblage and subsequent anomalous hydrological conditions have hampered assemblage recovery. These findings stress the need to account for climatic-driven hydrological changes in conservation efforts addressing aquatic biodiversity and fishery resources in the central Amazon.
气候变化和森林砍伐的综合影响改变了亚马逊地区的降水模式。这导致了近几十年来洪水和干旱极端事件的发生频率以及年洪水脉冲幅度的变化，这种现象几乎影响了河流-泛滥平原生态系统动态的各个方面。对亚马逊河和内格罗河交汇处附近一个泛滥平原湖泊的长期数据的分析揭示了水文学和鱼类组合结构的突然和同步变化。在 2005 年的一场强烈干旱之后，组合呈现出不同的、相当持久的分类组成和功能结构。2005 年后，所有具有平衡生活史策略、周期性生活史策略的大物种以及除初级消费者以外的所有营养级的物种的丰度下降更为明显。我们的研究结果表明，极端干旱引发了鱼类组合的变化，随后异常的水文条件阻碍了组合的恢复。这些发现强调了在保护努力中需要考虑到气候驱动的水文变化，以解决亚马逊中部地区的水生生物多样性和渔业资源问题。
