Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration

Science, Journal Year: 2019, Volume and Issue: 365(6459)

Published: Sept. 19, 2019

River ecosystems are highly biodiverse, influence global biogeochemical cycles, and provide valued services. However, humans increasingly degrading fluvial by altering their streamflows. Effective river restoration requires advancing our mechanistic understanding of how flow regimes affect biota ecosystem processes. Here, we review emerging advances in hydroecology relevant to this goal. Spatiotemporal variation exerts direct indirect control on the composition, structure, dynamics communities at local regional scales. Streamflows also processes, such as nutrient uptake transformation, organic matter processing, metabolism. We deepening biological not just static patterns, affected stream research nexus flow-biota-ecosystem processes is an early stage. illustrate frontier with evidence from altered regulated rivers urban streams. identify challenges that should be prioritized advance process-based restoration.

Language: Английский

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The role of dispersal in river network metacommunities: Patterns, processes, and pathways

Freshwater Biology, Journal Year: 2017, Volume and Issue: 63(1), P. 141 - 163

Published: Oct. 9, 2017

Abstract River networks are hierarchical dendritic habitats embedded within the terrestrial landscape, with varying connectivity between sites depending on their positions along network. This physical organisation influences dispersal of organisms, which ultimately affects metacommunity dynamics and biodiversity patterns. We provide a conceptual synthesis role river in structuring metacommunities relation to processes riverine ecosystems. explore where network best explains observed structure compared other measurements connectivity. mostly focus invertebrates, but also consider taxonomic groups, including microbes, fishes, plants, amphibians. Synthesising studies that multiple spatial distance metrics, we found importance itself explaining patterns depended variety factors, mode (aquatic versus aerial terrestrial) landscape type (arid mesic), as well location‐specific such connectivity, land use, topographic heterogeneity, biotic interactions. The appears be less important for strong dispersers insects arid systems than groups biomes, there is considerable variability. Borrowing from literature, particularly genetics, developed model predicts explanatory power peaks mesic obligate aquatic dispersers. propose directions future avenues research, use manipulative field laboratory experiments test theory networks. While have own benefits drawbacks (e.g. reality, control, cost), both powerful approaches understanding mechanisms metacommunities, by teasing apart niche‐related factors. Finally, improving our knowledge will benefit expanding breadth cost‐distance modelling better infer observational data; an improved life‐history strategies rather relying independent traits; exploring individual‐level variation through detailed genetic studies; fine‐scale environmental daily hydrology) organismal spatiotemporal variability; synthesising comparative, experimental, theoretical work. Expanding these areas help push current state science largely pattern‐detection into new phase more mechanistically driven research.

Language: Английский

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Beta diversity of diatom species and ecological guilds: Response to environmental and spatial mechanisms along the stream watercourse

Freshwater Biology, Journal Year: 2017, Volume and Issue: 63(1), P. 62 - 73

Published: Aug. 7, 2017

Abstract Understanding the mechanisms that drive beta diversity (i.e. β‐diversity), an important aspect of regional biodiversity, remains a priority for ecological research. β‐diversity and its components can provide insights into processes generating biodiversity patterns. We tested whether environmental filtering or dispersal related predominated along stream watercourse by analysing responses taxonomic functional diatom to spatial factors. examined variation in total (turnover nestedness) benthic species guilds (motile, planktonic, low‐ high profile) with respect position (up‐, mid‐ downstream) 2,182 sites throughout France. effects pure factors on partial Mantel tests. Environmental included eight physicochemical variables, while geographical distances between were used as also correlated α γ‐diversity, degree nestedness ( NODF metric) variables. Total turnover component displayed higher values upstream than downstream. The exhibited low values, even when increased from up‐ Pure highly significant explaining regardless position, but mostly downstream, distance being positively β‐diversity. Across sites, nutrient enrichment decreased nestedness. Motile profile diatoms comprised most abundant guilds, their patterns varied opposite way. lowest guild was observed species, downstream motile species. In conclusion, seemed play major role structuring metacommunities irrespective site position. Filtering promoted strong patterns, especially disconnected sites. greater consistent mass rather neutral because these had lower strongly affected processes, whereas primarily influenced conditions. Collectively, findings suggest partitioning use useful framework assessing underlying metacommunity watercourse.

Language: Английский

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The River Continuum Concept: lessons from the past and perspectives for the future

Canadian Journal of Fisheries and Aquatic Sciences, Journal Year: 2020, Volume and Issue: 77(11), P. 1853 - 1864

Published: July 31, 2020

The River Continuum Concept (RCC) is a milestone in stream ecology because of its comprehensive evaluation the structure and function lotic ecosystems. Linking physical geomorphological attributes with patterns biodiversity, functional traits, metabolism dynamics, this theory describes downstream gradients community composition ecosystem processes. aim review to evaluate how RCC, 40 years from publication Canadian Journal Fisheries Aquatic Sciences, has influenced basic applied research ecology, focusing on most important contributions recent developments. This work puts into perspective historical importance RCC scientific process integrates past theories, including metacommunity metaecosystem theories river network perspective, predict taxonomic diversity benthic communities. Thus, provides unifying overview context field for exploring ecological questions next generation ecologists.

Language: Английский

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Metacommunities in river networks: The importance of network structure and connectivity on patterns and processes

Freshwater Biology, Journal Year: 2017, Volume and Issue: 63(1), P. 1 - 5

Published: Dec. 18, 2017

Abstract Rivers are spatially organised into hierarchic dendritic networks. This unique physical structure and the associated directionality of flows set them apart from most other environments by regulating dispersal resident biota therefore distribution biodiversity. The aim this special issue is to highlight importance river network on structuring biodiversity, particularly through metacommunity dynamics processes. covers a wide range topics, including disease spread, nutrient uptake, trophic dynamics, effects anthropogenic stressors joint roles environmental filtering. Contributions employ broad approaches, field laboratory experiments, modelling, population genetics conceptual synthesis. Although these studies represent just sample research that being performed biodiversity in networks, several important findings have emerged; common theme spatial clearly influence populations communities, their functions. By taking taxonomic focus (from diatoms protists fish), spanning large geographic gradient tropics subarctic), provides look at occur networks relating makeup. We hope selection spurs additional interesting, globally important, yet severely threatened ecological systems.

Language: Английский

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Local environmental factors influence beta‐diversity patterns of tropical fish assemblages more than spatial factors

Ecology, Journal Year: 2019, Volume and Issue: 101(2)

Published: Nov. 21, 2019

A major goal in ecology is to understand mechanisms that influence patterns of biodiversity and community assembly at various spatial temporal scales. Understanding how composition created maintained also critical for natural resource management biological conservation. In this study, we investigated environmental factors influencing beta diversity local fish assemblages along the longitudinal gradient a nearly pristine Neotropical river Colombian Llanos. Standardized surveys were conducted during low-water season 34 sites within Bita River Basin. Physical, chemical, landscape parameters recorded each site, asymmetric eigenvector maps used as variables. To examine relative dispersal variables on its components, distance-based redundancy analysis (db-RDA) variation partitioning conducted. We proposed scale position network would constrain different ways. However, results indicated system, high was consistent among species no matter or network. Species replacement (turnover) dominated diversity, an indication importance sorting. These findings suggested conservation tropical rivers requires maintenance both habitat heterogeneity (spatial conditions) connectivity entire basins.

Language: Английский

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Biological Diversity in Headwater Streams

Water, Journal Year: 2019, Volume and Issue: 11(2), P. 366 - 366

Published: Feb. 21, 2019

Headwaters, the sources of all stream networks, provide habitats that are unique from other freshwater environments and used by a specialised subset aquatic species. The features headwaters special include predator-free or competitor-free spaces; specific resources (particularly detrital based); moderate variations in flows, temperature discharge. Headwaters key for some life stages large number species across just about phyla divisions. Some headwaters, including isolation small population sizes, have allowed evolutionary radiation many groups organisms within beyond those habitats. As easily engineered physical spaces, degraded streambank development, ditching even burial. Headwater streams among most sensitive ecosystems due to their intimate linkage with catchments how they impacted. ecosystem specialist species, headwater deserve better stewardship.

Language: Английский

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River network connectivity and fish diversity

The Science of The Total Environment, Journal Year: 2019, Volume and Issue: 689, P. 21 - 30

Published: June 24, 2019

Language: Английский

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Drainage network position and historical connectivity explain global patterns in freshwater fishes’ range size

Proceedings of the National Academy of Sciences, Journal Year: 2019, Volume and Issue: 116(27), P. 13434 - 13439

Published: June 17, 2019

Significance Species’ geographic range size is a fundamental aspect of understanding and predicting changes in biodiversity patterns. Investigating the global drivers variation freshwater fishes, we found clear evidence that current historical connectivity are, by far, main determinants size. More specifically, that, everything else being equal, species displaying basal position drainage network (i.e., lowland areas) basins have had connections during Quaternary low-sea-level periods larger sizes than their counterparts. Our findings suggest key component riverine fish sizes. This may important implications for evaluating vulnerability to river fragmentation.

Language: Английский

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The Landscape Ecology of Rivers: from Patch-Based to Spatial Network Analyses

Current Landscape Ecology Reports, Journal Year: 2019, Volume and Issue: 4(4), P. 103 - 112

Published: Nov. 16, 2019

Abstract Purpose of Review We synthesize recent methodological and conceptual advances in the field riverscape ecology, emphasizing areas synergy with current research landscape ecology. Recent Findings ecology highlight need for spatially explicit examinations how network structure influences ecological pattern process, instead simple linear (upstream-downstream) view. Developments GIS, remote sensing, computer technologies already offer powerful tools application patch- gradient-based models characterizing abiotic biotic heterogeneity across a range spatial temporal scales. Along graph-based analyses statistical stream (i.e., geostatistical modelling), these approaches improved capabilities quantifying connectivity relationships, thereby allowing rigorous high-resolution pattern, scale relationships. Summary Spatially are able to quantify predict biogeochemical, hydromorphological, patterns processes more precisely than based on longitudinal or lateral riverine gradients alone. Currently, local habitat characteristics appear be important effects determining population community dynamics, but this conclusion may change direct quantification movement materials, energy, organisms along channels ecosystem boundaries—a key improving Coupling optimization will improve land protection water management efforts, help resolve sharing vs. sparing debate.

Language: Английский

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