Understanding the patterns and mechanisms of biodiversity and its organization in space is essential for developing effective conservation strategies. Zeta diversity is an index of how taxa are shared by several sites, providing information on how ecological filters, including anthropogenic disturbances, influence biodiversity distribution. This study documents how anthropogenic disturbances at multiple spatial extents affect the spatial variation of benthic macroinvertebrate assemblages in lotic ecosystems.
View Article and Find Full Text PDFThe extent of alien taxa impacts on river ecosystem health is unclear, but their frequency continues to rise. We investigated 1) the prevalence of including alien taxa in common bioindicators used in river bioassessment, 2) the effect of alien taxa on the richness and abundance of natives, and 3) whether including alien taxa in bioassessment tools increased their sensitivity to river degradation. In the 17 countries analyzed fish represented the greatest number of alien species (1726), followed by macrophytes (925), macroinvertebrates (556), and diatoms (7).
View Article and Find Full Text PDFExcessive fine sediment (particles <2 mm) deposition in freshwater systems is a pervasive stressor worldwide. However, understanding of ecological response to excess fine sediment in river systems at the global scale is limited. Here, we aim to address whether there is a consistent response to increasing levels of deposited fine sediment by freshwater invertebrates across multiple geographic regions (Australia, Brazil, New Zealand and the UK).
View Article and Find Full Text PDFBiological communities have their biodiversity patterns affected by environmental, spatial, and biogeographic factors that vary from taxa to taxa, and often between life stages. This is especially true when there are differences in the habitat the species use in each of them. Individuals of the insect order Trichoptera are mostly aquatic in their larval stage and terrestrial in their adult stage, which may result in different behaviors and environmental requirements.
View Article and Find Full Text PDFOver 70% of the total channel length in all river basins is formed by low order streams, many of which originate on mountaintops. Headwater streams play fundamental roles in processing and transporting terrestrial and aquatic organic matter, often harboring high biodiversity in bottom leaf patches deposited from riparian vegetation. The objective of this study was to assess the variation in taxonomic composition (measured by beta diversity of aquatic macroinvertebrates) among stream sites located in the Espinhaço Meridional Mountain Range, part of a UNESCO Biosphere Reserve in eastern Brazil.
View Article and Find Full Text PDFRiparian zones ensure freshwater ecosystem processes such as microclimate regulation, organic matter inputs, and fine substrate retention. These processes illustrate the importance of riparian zones for freshwater ecosystem functioning, maintaining biodiversity, and mitigating the effects of anthropogenic pressures on aquatic ecosystems. We aimed to determine the freshwater invertebrate biological traits that are most affected by anthropogenic stressors in the riparian zones of 210 Neotropical savanna headwater streams.
View Article and Find Full Text PDFRiparian vegetation cover influences benthic assemblages structure and functioning in headwater streams, as it regulates light availability and autochthonous primary production in these ecosystems.Secondary production, diversity, and exergy-based indicators were applied in capturing how riparian cover influences the structure and functioning of benthic macroinvertebrate assemblages in tropical headwater streams. Four hypotheses were tested: (1) open canopy will determine the occurrence of higher diversity in benthic macroinvertebrate assemblages; (2) streams with open canopy will exhibit more complex benthic macroinvertebrate communities (in terms of information embedded in the organisms' biomass); (3) in streams with open canopy benthic macroinvertebrate assemblages will be more efficient in using the available resources to build structure, which will be reflected by higher eco-exergy values; (4) benthic assemblages in streams with open canopy will exhibit more secondary productivity.
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