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Abstract We investigated how the taxonomic and functional structures of fish assemblages in the lower Amazon River floodplain responded to seasonal hydrological variations. Fishes were sampled in 440 aquatic habitats across a floodplain area of 17,673 km2during periods of high, receding, low and rising water. In addition, we recorded local environmental and landscape variables known to affect fish assemblages in floodplains. Redundancy analysis indicated that the taxonomic and functional structures of the fish assemblages were associated with water levels as well as local environmental, landscape and spatial variables. Our results showed that piscivores, planktivores and omnivores, as well as species with periodic and intermediate life history strategies, dominated the floodplain fish assemblages during periods of high‐water levels, whereas herbivores, invertivores and detritivores, as well as species of large body size with an equilibrium life history strategy, dominated the fish assemblages during periods of low‐water levels. Hydrology strongly influenced the structure of the fish assemblages in the Amazon floodplains. Our results indicate that the maintenance of seasonal hydrological dynamics in the basin is essential for the conservation of the regional fish diversity.
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Fish species richness is associated with the availability of landscape components across seasons in the Amazonian floodplain
Understanding environmental biodiversity drivers in freshwater systems continues to be a fundamental challenge in studies of their fish assemblages. The present study seeks to determine the degree to which landscape variables of Amazonian floodplain lakes influences fish assemblages in these environments. Fish species richness was estimated in 15 Amazonian floodplain lakes during the high and low-water phases and correlated with the areas of four inundated wetland classes: (i) open water, (ii) flooded herbaceous, (iii) flooded shrubs and (iv) flooded forest estimated in different radius circular areas around each sampling site. Data were analyzed using generalized linear models with fish species richness, total and guilds as the dependent variable and estimates of buffered landscape areas as explanatory variables. Our analysis identified the significance of landscape variables in determining the diversity of fish assemblages in Amazonian floodplain lakes. Spatial scale was also identified as a significant determinant of fish diversity as landscape effects were more evident at larger spatial scales. In particular, (1) total species richness was more sensitive to variations in the landscape areas than number of species within guilds and (2) the spatial extent of the wetland class of shrubs was consistently the more influential on fish species diversity.
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- Award ID(s):
- 1639115
- PAR ID:
- 10393525
- Date Published:
- Journal Name:
- PeerJ
- Volume:
- 6
- ISSN:
- 2167-8359
- Page Range / eLocation ID:
- e5080
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.7717/peerj.5080
