Floodplain land cover affects biomass distribution of fish functional diversity in the Amazon River
Floodplain land cover affects biomass distribution of fish functional diversity in the Amazon River
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DOI：
10.1038/s41598-019-52243-0
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发表时间：
2019-11-13
影响因子：
4.6
通讯作者：
Freitas, Carlos E. C.
中科院分区：
文献类型：
--
作者：
Arantes, Caroline C.;Winemiller, Kirk O.;Freitas, Carlos E. C.
土地覆盖变化经常改变动物群落生物量的分布。然而，对于许多生物和生态系统，特别是洪泛平原，土地覆盖变化对功能多样性的影响仍然知之甚少。我们假设洪泛平原鱼类功能多样性的生物量分布与土地覆盖有关，这意味着鱼类特征影响对土地覆盖梯度的行为和/或人口响应。利用对亚马逊河漫滩462个生境的调查数据，我们拟合了统计模型来解释所有鱼类的功能多样性和生物量的景观尺度变化，以及具有不同功能特征的物种亚群。森林覆盖与鱼类生物量呈正相关，这种关系的强度根据生活史、营养、迁徙和游泳性能/微生境利用特征所定义的功能群而变化。42%的功能类群，包括那些推断在森林栖息地有更好的取食机会、生长和/或繁殖成功的功能类群，在森林覆盖更大的地方有更大的生物量。相反，其他功能类群的生物量，包括生境通用型和直接利用本地食物资源的功能类群，与森林覆盖的关系没有显著变化。局部组合所占的生态位空间（功能丰富度）和性状丰度的分散度（功能分散度）随森林覆盖的增加而增加。我们的研究支持了这样的预期，即亚马逊河漫滩的森林砍伐不仅影响鱼类生物量，还影响功能多样性，其中一些功能群特别脆弱。
Land-cover change often shifts the distribution of biomass in animal communities. However, the effects of land-cover changes on functional diversity remain poorly understood for many organisms and ecosystems, particularly, for floodplains. We hypothesize that the biomass distribution of fish functional diversity in floodplains is associated with land cover, which would imply that fish traits affect behavioral and/or demographic responses to gradients of land cover. Using data from surveys of 462 habitats covering a range of land-cover conditions in the Amazon River floodplain, we fitted statistical models to explain landscape-scale variation in functional diversity and biomass of all fish species as well as subsets of species possessing different functional traits. Forest cover was positively associated with fish biomass and the strength of this relationship varied according to functional groups defined by life history, trophic, migration, and swimming-performance/microhabitat-use traits. Forty-two percent of the functional groups, including those inferred to have enhanced feeding opportunities, growth, and/or reproductive success within forested habitats, had greater biomass where forest cover was greater. Conversely, the biomass of other functional groups, including habitat generalists and those that directly exploit autochthonous food resources, did not vary significantly in relation to forest cover. The niche space occupied by local assemblages (functional richness) and dispersion in trait abundances (functional dispersion) tended to increase with forest cover. Our study supports the expectation that deforestation in the Amazon River floodplain affects not only fish biomass but also functional diversity, with some functional groups being particularly vulnerable.