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Streams and ponds provide several ecosystem services but are threatened by anthropic activities. Studies on species contribution and local uniqueness are ways of analyzing sites that need conservation or restoration due to anthropic activities. These metrics are especially important when evaluating Amazonian environments, which are complex and understudied. In this study, we investigated the relationships between the local contribution (LCBD) and the species contribution (SCBD) to beta diversity and community attributes for zooplankton in Amazonian streams and ponds, and those between the land use change and local environmental factors on the LCBD (total, replacement, and richness difference). Additionally, we investigated whether sites with ecological uniqueness should be considered for conservation or restoration. We sampled zooplankton, macrophytes, and physical–chemical variables in 42 streams and 26 ponds in 2022. We also determined land use and land cover through digital image processing and calculated the Catchment Disturbance Index (CDI). A total of 130 taxa, comprising 76 rotifers, 41 cladocerans, and 13 copepods, were recorded. The zooplankton SCBD was positively correlated with species occurrence and abundance of individuals, while the LCBD was negatively related to abundance and species richness. In streams, total-LCBD was positively related to CDI and negatively related to macrophyte cover; in ponds, no significant relationship was observed. Our results improve current understanding of the effects of land use changes on zooplankton beta diversity, showing that more altered sites have unique and poor species composition and need restoration. Our data also increase knowledge on zooplankton in Amazonian environments, especially in streams that are understudied. [ABSTRACT FROM AUTHOR]

Amazon streams present great biodiversity and offer several ecosystem services, but these systems are threatened by multiple land uses. The changes created by land use are expected to drive the composition of species, ultimately changing the trophic relationships of several biological groups, including zooplankton. We investigated if land use changes the composition of zooplankton functional guilds in Amazon streams and which are the local (physical-chemical) variables driving the zooplankton functional guilds in the land-use gradient. Zooplankton and physical-chemical variables were sampled in 17 water bodies in the municipality of Barcarena, Pará, Brazil in 2018 and 2019, five sampling sites were in the Pará River and 12 in streams. Forest cover (a proxy for land use) was determined through digital image processing and converted in percentage. Zooplankton species were classified into five functional guilds (filter, raptorial, scraper, suctor, and predator feeders). We recorded 98 zooplankton taxa and filters were the most abundant functional guild. The composition of zooplankton functional guilds did not change in the land use gradient. However, the distribution of zooplankton functional guilds in Amazon streams was determined by local environmental variables related to the feeding strategies. Scraper-feeders (cladocerans) were positively related to greater canopy cover, suctor-feeders and predator-feeders (both rotifers) were related to greater total phosphorus, whereas filter-feeders (rotifers, cladocerans, and copepods) and raptorial (copepods) were related to total suspended solids. This study brings new information about zooplankton in Amazon streams that are under-studied. The functional approach clarifies the patterns observed and reflects the trophic relationships in which the zooplankton community is involved in streams under a degree of land use, i.e., scraper-cladocerans can represent more preserved streams under greater canopy cover, whereas the other functional guilds were related to variables that can represent more altered streams. [ABSTRACT FROM AUTHOR]

Land use has transformed landscapes, altered water and soil physical–chemical parameters, reduced habitat availability, and limited species occurrence. Here, we investigated the contribution of sites (local contribution to beta diversity—LCBD) and species (species contribution to beta diversity—SCBD) to macrophyte total β-diversity in streams inserted in a gradient of land use. We also investigated which life forms are important to SCBD and which environmental parameters are related to the change in the species composition. Sampling took place in 17 streams located in Paragominas, Pará, Brazil in September 2017. We recorded 36 species and four life forms. We identified five sites with high LCBD. The species with the four highest SCBD scores belong to the amphibious life form. CDI (Catchment Disturbance Index) and canopy cover, variables that show land use degrees, drove the distribution of macrophyte species in the land use gradient. CDI presented a positive relationship with LCBD, whereas canopy cover presented a negative relationship, i.e., a greater composition of unique species and greater diversity of macrophytes life forms were found in more altered streams than in preserved ones, due to canopy openness. Nonetheless, we emphasize that although the environmental characteristics of altered streams favored the establishment of more macrophytes species, the species found could be generalists and the pattern for other types of environments is usually the opposite. Therefore, studies focusing on temporal patterns will be important for this area to understand how the macrophyte community will stabilize. This study brings important contributions to elucidate the effects of land use on macrophytes distribution and the role played by different life forms. [ABSTRACT FROM AUTHOR]

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