Geomorphic context in process‐based river restoration

River Research and Applications, Journal Year: 2024, Volume and Issue: 40(3), P. 322 - 340

Published: Jan. 2, 2024

Abstract Process‐based river restoration seeks to restore processes such as channel‐floodplain connectivity that create and maintain corridor functions. can fail produce the desired results if geomorphic context is not effectively incorporated into design. Geomorphic of a reach refers controls on contemporary form process. Controls at catchment‐ reach‐scale include geologic history, biophysical characteristics, legacies past human alterations, position within network, geometry, base level stability, disturbance regime, alterations corridor. We conceptualize reflecting interactions among fluxes material context. discuss how an understanding be used select approach provide examples achieve outcomes when considered. Within toolbox methods implement process‐based restoration, we differentiate alteration inputs through from and/or Historical, biotic, geologic/geomorphic, reference sites inform targets. Restoration strongly influenced by perceptions what appropriate achievable site diverse communities influencing may differ in their perceptions. Geomorphically based conceptual guidelines, River Styles Framework, effective platform for incorporating restoration.

Language: Английский

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The potential for nature-based solutions to combat the freshwater biodiversity crisis

PLOS Water, Journal Year: 2023, Volume and Issue: 2(6), P. e0000126 - e0000126

Published: June 8, 2023

Enthusiasm for and investments in nature-based solutions (NBS) as sustainable strategies climate adaptation infrastructure development is building among governments, the scientific community, engineering practitioners. This particularly true water security water-related risks. In a freshwater context, NBS may provide much-needed “win-wins” society environment that could benefit imperiled biodiversity. Such conservation benefits are urgently needed given ongoing biodiversity crisis, with declines species their habitats occurring at more than twice rate of marine or terrestrial systems. However, to make meaningful contributions safeguarding biodiversity, clear links must be established between applications priorities conservation. this paper, we link common six priority actions life by science n highlight research knowledge will necessary bring bear on crisis. particular, illustrate how can play direct role restoring degraded aquatic floodplain ecosystems, enhancing in-stream quality, improving hydrological connectivity ecosystems. System-level monitoring ensure deliver promised ecosystems species.

Language: Английский

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Bending the curve of global freshwater biodiversity loss: what are the prospects?

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 2, 2024

ABSTRACT Freshwater biodiversity conservation has received substantial attention in the scientific literature and is finally being recognized policy frameworks such as Global Biodiversity Framework its associated targets for 2030. This important progress. Nonetheless, freshwater species continue to be confronted with high levels of imperilment widespread ecosystem degradation. An Emergency Recovery Plan (ERP) proposed 2020 comprises six measures intended “bend curve” loss, if they are widely adopted adequately supported. We review evidence suggesting that combined intensity persistent emerging threats become so serious current projected efforts preserve, protect restore inland‐water ecosystems may insufficient avert losses coming decades. In particular, climate change, complex harmful impacts, will frustrate attempts prevent from already affected by multiple threats. Interactions among these limit recovery populations exacerbate declines resulting local or even global extinctions, especially low‐viability degraded fragmented ecosystems. addition impediments represented we identify several other areas where absolute scarcity fresh water, inadequate information predictive capacity, a failure mitigate anthropogenic stressors, liable set limits on biodiversity. Implementation ERP rapidly at scale through many dispersed actions focused regions intense threat, together an intensification ex‐situ efforts, necessary preserve native during increasingly uncertain climatic future which poorly understood, emergent interacting have more influential. But implementation must accompanied improve energy food security humans – without further compromising condition Unfortunately, political policies arrest environmental challenges change do not inspire confidence about possible success ERP. parts world, Anthropocene seems certain include extended periods uncontaminated surface runoff inevitably appropriated humans. Unless there step‐change societal awareness commitment biodiversity, established methods protecting bend curve enough continued degradation loss.

Language: Английский

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Responses of multimetric indices to disturbance are affected by index construction features

Environmental Reviews, Journal Year: 2024, Volume and Issue: 32(2), P. 278 - 293

Published: Feb. 22, 2024

Multimetric indices (MMIs) are used worldwide to assess the ecological conditions of aquatic and terrestrial ecosystems. Different criteria approaches construct MMIs, resulting in widely different indices. Therefore, scientists, managers, policymakers sometimes question whether such MMIs useful for biomonitoring bioassessment programs. Crucial design issues programs include MMI responsiveness, bioindicator group used, survey design, field sampling methods, level taxonomic resolution, metric selection scoring, reference condition identification. We performed a meta-analysis on development applications analyze response disturbance factors determine degree which construction features influence their responsiveness anthropogenic disturbances. Web Science database find articles that applied an related values environmental stressor, we extracted data from 157 articles. random-effects modeling estimate overall effect responses subgroup analysis extent sizes varied as function features. found had major disturbance. The type, number metrics, ecosystem type were contributed more weakly size variance. general was little affected by group, criteria, or scoring method. These findings have important implications designing programs, including developing improving cost-effective biological indices, because they could enhance application protocols.

Language: Английский

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Vegetation responses to large dam removal on the Elwha River, Washington, USA

Frontiers in Ecology and Evolution, Journal Year: 2024, Volume and Issue: 12

Published: Feb. 13, 2024

Large dam removal can trigger changes to physical and biological processes that influence vegetation dynamics in former reservoirs, along river corridors downstream of dams, at a river’s terminus deltas estuaries. We present the first comprehensive review response major fluvial disturbance caused by world’s largest removal. After being place for nearly century, two large dams were removed Elwha River, Washington, USA, between 2011 2014. The exposure, erosion, transport, deposition volumes sediment wood impounded behind created new surfaces where plant colonization growth have occurred. In exposed ~290 ha unvegetated distributed on three main landforms: valley walls, high terraces, dynamic floodplains. addition natural revegetation weed control seeding planting desirable plants influenced trajectories. early years following removal, ~20.5 Mt trapped eroded from reservoirs transported downstream. This pulse, combination with transport wood, led channel widening, an increase gravel bars, floodplain deposition. primary responses corridor reduction vegetated area associated establishment increased hydrochory, altered community composition bars Plant species diversity some segments. delta, creation ~26.8 land distribution intertidal water bodies. Vegetation colonized ~16.4 surfaces: mixed pioneer supratidal beach, mouth emergent marsh aquatic habitats. sediment-dominated opportunities growth, such as restored hydrochory anadromous fish passage delivery marine-derived nutrients may over time. Rapid landforms related pulse rate change is expected attenuate system adjusts flow regimes.

Language: Английский

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A Watershed Moment for Western U.S. Dams

Water Resources Research, Journal Year: 2023, Volume and Issue: 59(10)

Published: Oct. 1, 2023

Abstract The summer of 2023 is a notable time for water‐resource management in the western United States: Glen Canyon Dam, on Colorado River, turns 60 years old while largest dam‐removal project history beginning Klamath River. This commentary discusses these events context changing paradigm dam and reservoir this region. Since era large building began to wane six decades ago, new challenges have arisen owing climate change, population increase, sedimentation, declining safety aging dams, more environmentally focused objectives. Today we also better understand dams' benefits, costs, environmental impacts, including some that were unforeseen took become apparent. Where dams unsafe, obsolete (e.g., due excessive sedimentation), uneconomical beyond saving, removal has common. science practice are accelerating rapidly, long‐term physical biological response studies now available. Removal four hydroelectric River will be larger complex than any previous removal. imminency reflects very different situation ago. Looking forward, States worldwide require continued collaboration innovative thinking meet wide range objectives manage water resources sustainably future generations.

Language: Английский

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Spatial and temporal taxonomic and functional beta diversity of macroinvertebrate assemblages along a tropical dammed river

Aquatic Sciences, Journal Year: 2025, Volume and Issue: 87(2)

Published: Jan. 31, 2025

Language: Английский

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Restoration of river connectivity enables long-distance spawning migrations in a potamodromous fish

Journal of Environmental Management, Journal Year: 2025, Volume and Issue: 377, P. 124646 - 124646

Published: Feb. 22, 2025

Rivers across the world are increasingly fragmented due to anthropogenic barriers, with restoration of connectivity often using fish passes. Fish passes are, however, usually designed for anadromous species, despite ecologically important non-anadromous species being present in communities impacted by fragmentation. To assess outcomes fishes installation multiple and weir modifications, movements potamodromous European barbel Barbus barbus were evaluated lower River Severn basin, western Britain, which was six weirs (two on a tributary, four mainstem). Movements individual measured long-life acoustic transmitters, stable isotope analysis assisting assessment variability movements. The three tagging groups measured: tagged 2015 (n = 19; no passes/modifications), 2018 tributary modified), 2020/21 20; all mainstem fitted passes). No group passed mainstem, approaches, only one most downstream during high water conditions winter. Following opening early 2021, individuals moved above via between April June (the spawning season). These then upstream up 110 km, some detected returning downstream. migrations potentially have ecological evolutionary significance, indicating that reconnection schemes also benefit fishes.

Language: Английский

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Riverine Barrier Removals Could Proliferate Biological Invasions

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(3)

Published: March 1, 2025

Multiple stressors, such as pollution, climate change, invasive species and fragmentation, threaten global ecosystems, requiring holistic management actions. Freshwater ecosystems are disproportionately biodiverse particularly impacted by fragmentation biological invasions. Artificial barriers, dams weirs, long-standing features of landscapes, with a divergence views on their benefits disbenefits. Recognition the negative impacts barriers river continuum native biota, for migratory aquatic species, has led to rapid rate barrier removals in recent decades, especially North America Europe. However, since rise riverine construction centuries ago, invasion rates have concurrently surged. can paradoxically slow spread through freshwaters, removal efforts thus risk proliferating that disperse rapidly connected habitats. Despite well-intended plans restoration removals, subsequent colonisation been largely overlooked. This presents 'connectivity conundrum': intuitively addresses issues migrations dispersals, but could perversely exacerbate species. Basin-scale data collection around short- long-term will help underpin future projects maximise potential beneficial outcomes

Language: Английский

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Global consequences of dam‐induced river fragmentation on diadromous migrants: a systematic review and meta‐analysis

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 7, 2025

ABSTRACT The global proliferation of dams has altered flow and sediment regimes in rivers, presenting a major threat to freshwater biodiversity. Diadromous species, such as fishes, decapod crustaceans gastropods, are particularly susceptible fragmentation because obstruct their breeding migrations between coastal waters rivers. Although have contributed significant declines abundance some commercially important diadromous fishes (salmonids anguillids) Macrobrachium shrimps, understanding the impacts on majority animals is limited. Moreover, number species known life cycles risen substantially during last four decades, from ~250 more than 800. This synthesis aims consolidate highlight potential knowledge gaps. We identified 338 publications documenting decapods, but this was reduced 65 after application our strict selection criteria. Specifically, we only included studies that compared unfragmented (e.g. undammed) or restored with fish passes) fragmented site above dams) To assess statistical significance, results were replicated sufficiently enable calculation standardised effect sizes also subject meta‐analysis focusing three topics: dam‐induced fragmentation; efficacy passes; mitigative dam removal. Study outcomes evaluated five key variables: abundance; richness; assemblage composition; population genetic diversity; structure. found led net negative effects across all variables for fishes. Fishes limited jumping climbing ability obligate migrants cannot persist landlocked populations threatened by fragmentation. However, capable climbers jumpers facultatively nonetheless impacts, gene populations. Installation passes did not lead positive outcomes, whereas removal effective restoring connectivity suggesting it effective, albeit potentially contentious, approach may serve an societal need), habitat connectivity. A smaller investigated decapods (seven versus 61 fishes), findings suggests vulnerable alteration dams, less sensitive barrier they better Gastropods least studied taxon, none met criteria systematic review meta‐analysis. imbalance information about taxa compounded scarcity tropics, South America, Africa, Asia, Southeast East Asia. These regions support diverse aquatic assemblages so be underestimated given existing conservation would best served avoiding construction while improving mitigation strategies, passage design, limit most damaging river

Language: Английский

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