Effects of a major Amazonian river confluence on the distribution of floodplain forest avifauna

Aim: Although “river color” or water type is an important determinant of Amazonian floodplain biodiversity, the relevance of mixing distinct water types at river confluences to the distribution of terrestrial floodplain fauna has been largely overlooked. We investigated how the influx of a sediment-rich whitewater tributary affects the floodplain forest avifauna along the world’s largest blackwater river.

Location: Northwestern Brazilian Amazon

Taxon: Birds

Methods: We sampled floodplain avifauna and retrieved estimates of sediment concentration in the water (the main parameter in river-water classification) at 52 sites, along the Negro (blackwater) and Branco (whitewater) rivers, above and below their confluence. We compared species richness and composition using analyses of variance, ordinations, generalized linear models and indicator species analyses.

Results: Bird species composition on the lower Rio Negro (below the confluence) was distinct from both the upper Negro (a...

研究目标：尽管“河水颜色”或水体类型是亚马逊洪泛平原（floodplain）生物多样性的重要决定因素，但河流汇流（confluence）处不同水体混合过程与陆地洪泛平原动物群分布的相关性，在很大程度上被忽视了。本研究针对全球最大的黑水河——内格罗河沿岸，探究富含沉积物的白水支流的输入如何影响其洪泛平原森林鸟类区系（avifauna）。
研究区域：巴西亚马逊西北部
研究类群：鸟类
研究方法：在汇流上下游的内格罗河（黑水河）与布兰科河（白水河）沿岸共52个采样点，对洪泛平原鸟类区系进行采样，并获取水体沉积物浓度（河水分类的核心参数）的估算值。采用方差分析、排序分析、广义线性模型（generalized linear models）以及指示物种分析（indicator species analyses），对物种丰富度与群落组成进行比较。
研究结果：下游里奥内格罗河（汇流下游）的鸟类物种组成，既区别于上游内格罗河（原文未完）……