Hydrodynamics of vegetated channels

Journal of Hydraulic Research, Journal Year: 2012, Volume and Issue: 50(3), P. 262 - 279

Published: June 1, 2012

This paper highlights some recent trends in vegetation hydrodynamics, focusing on conditions within channels and spanning spatial scales from individual blades, to canopies or patches, the channel reach. At blade scale, boundary layer formed plant surface plays a role controlling nutrient uptake. Flow resistance light availability are also influenced by reconfiguration of flexible blades. canopy there two flow regimes. For sparse canopies, resembles rough layer. dense mixing reach is more closely connected patch-scale distribution, described blockage factor, than geometry plants. The impact distribution sediment movement discussed, with attention being paid methods for estimating bed stress regions vegetation. key research challenges hydrodynamics vegetated highlighted.

Language: Английский

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The fundamental role of ecological feedback mechanisms for the adaptive management of seagrass ecosystems – a review

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2016, Volume and Issue: 92(3), P. 1521 - 1538

Published: Sept. 1, 2016

ABSTRACT Seagrass meadows are vital ecosystems in coastal zones worldwide, but also under global threat. One of the major hurdles restricting success seagrass conservation and restoration is our limited understanding ecological feedback mechanisms. In these ecosystems, multiple, self‐reinforcing feedbacks can undermine efforts by masking environmental impacts until decline precipitous, or alternatively they inhibit recovery spite efforts. However, no clear framework yet exists for identifying dealing with to improve management ecosystems. Here we review causes consequences multiple between biotic and/or abiotic processes. We demonstrate how have potential impose reinforce regimes either dominance unvegetated substrate, strength importance vary across gradients. Although a myriad now been identified, co‐occurrence likely interaction among has largely overlooked date due difficulties analysis detection. take fundamental step forward modelling interactions two distinct above‐ belowground that interacting be important ecosystem resilience. On this basis, propose five‐step adaptive plan address dynamics effective strategies. The provides guidance aid identification prioritisation different

Language: Английский

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Recovery trajectories during state change from bare sediment to eelgrass dominance

Marine Ecology Progress Series, Journal Year: 2012, Volume and Issue: 448, P. 209 - 221

Published: Jan. 6, 2012

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 448:209-221 (2012) - DOI: https://doi.org/10.3354/meps09574 Recovery trajectories during state change from bare sediment eelgrass dominance Karen J. McGlathery1,*, Laura K. Reynolds1, Luke W. Cole1, Robert Orth2, Scott R. Marion2, Arthur Schwarzschild1 1Department of Environmental Sciences, University Virginia, PO Box 400123, Charlottesville, Virginia 22903, USA 2Virginia Institute Science, School 1208 Greate Road, College William and Mary, Gloucester Point, 23062, *Email: [email protected] ABSTRACT: Seagrasses are important foundation species in shallow coastal ecosystems that provide critical ecosystem services including stabilizing sediment, sequestering carbon nutrients, providing habitat an energy source for a diverse fauna. We followed recovery functional (primary productivity, nitrogen sequestration, deposition) structural (shoot density, biomass, plant morphometrics) attributes Zostera marina (eelgrass) meadows replicate large plots (0.2 0.4 ha) restored by seeding successive years, resulting chronosequence sites 0 (unvegetated) 9 yr since seeding. Shoot density was metric changed most significantly, with initial 4 lag, rapid, linear increase 6 after Changes Z. aerial organic content, exchangeable ammonium showed similar trend lag period before differences were observed conditions. After yr, had 20× higher rates areal productivity than 1 3 old meadows, double matter concentrations, 3× more 4× nitrogen, accumulated retained finer particles bare, unvegetated sediments. These results demonstrate reinstatement key successful large-scale restoration, although none parameters reached asymptote indicating at least decade is required these be fully restored, even area high suitability. Survivorship along depth gradient ~1.6 m (mean sea level) maximum limit marina, which matches ‘tipping point’ survival predicted this system non-linear hydrodynamic/seagrass growth model. KEY WORDS: Eelgrass · Restoration Seagrass Coastal bays Ecosystem Full text pdf format PreviousNextCite article as: McGlathery KJ, Reynolds LK, Cole LW, Orth RJ, Marion SR, Schwarzschild A dominance. Mar Ecol Prog Ser 448:209-221. Export citation Tweet linkedIn Cited Published Vol. 448. Online publication date: February 23, 2012 Print ISSN: 0171-8630; 1616-1599 Copyright © Inter-Research.

Language: Английский

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Seagrass blue carbon spatial patterns at the meadow-scale

PLoS ONE, Journal Year: 2017, Volume and Issue: 12(4), P. e0176630 - e0176630

Published: April 27, 2017

Most information on seagrass carbon burial derives from point measurements, which are sometimes scaled by meadow area to estimate stocks; however, sediment organic (Corg) concentrations may vary with distance the edge, resulting in spatial gradients that affect accuracy of stock estimates. We mapped Corg throughout a large (6 km2) restored determine whether distribution patterns exist at different scales. The originated ≤1-acre plots seeded between 2001 and 2004, so we expected spatially according known age sample sites proximity edge. Applying autoregressive models allowed us control for autocorrelation quantify relative effects edge concentrations. found proximity, not age, significantly predicted meadow-scale distribution. also evaluated relationships variety specific explanatory variables, including site exposure, shoot density, grain size, bathymetry. Factors plot-scale, such as were significant controls Strong correlations Corg, suggest current attenuation increases fine-sediment deposition and, therefore, into meadow. By mapping pool, provide first accurate quantification an enhanced attributable restoration. top 12 cm bed contain 3660 t approximately 1200 more than equal bare sediment. net increase is concentrated low tidal velocities. Managers should account configuration velocity when estimating blue stocks. Our results large, contiguous store small patches.

Language: Английский

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Feedback between sediment and light for seagrass: Where is it important?

Limnology and Oceanography, Journal Year: 2016, Volume and Issue: 61(6), P. 1937 - 1955

Published: June 24, 2016

A feedback between seagrass presence, suspended sediment and benthic light can induce bistability two ecosystem states: one where the presence of reduces concentrations to increase availability thereby favoring growth, another absence increases turbidity reducing growth. This literature review identifies (1) how environmental meadow characteristics influence strength direction (stabilizing or destabilizing) seagrass-sediment-light feedback, (2) this has been incorporated in models proposed support decision making. Large, dense meadows shallow subtidal, non-eutrophic systems, growing sediments mixed grain size subject higher velocity flows, have greatest potential generate via feedback. Conversely, low density, area height enhance turbulent flows that interact with seabed, causing water clarity decline. Using a published field experiment as case study, we show only if sufficient attenuation properties. The considered very few models. These identify areas occurs, which is information assist spatial prioritization conservation restoration efforts. In present predicted, recovery may be difficult once lost. bare predicted (without bistability) better targets for than predicted.

Language: Английский

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A laboratory study on sediment resuspension within arrays of rigid cylinders

Advances in Water Resources, Journal Year: 2016, Volume and Issue: 92, P. 1 - 9

Published: April 6, 2016

Language: Английский

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Turbulence as the Main Driver of Resuspension in Oscillatory Flow Through Vegetation

Journal of Geophysical Research Earth Surface, Journal Year: 2018, Volume and Issue: 123(5), P. 891 - 904

Published: April 6, 2018

A series of laboratory experiments was conducted using arrays rigid cylinders in a sandy bed as proxy for mangrove roots and benthos. Synchronous colocated measurements velocity suspended sediment concentration were recorded within the array to investigate effect density on resuspension under different wave conditions. The measured increase turbulent kinetic energy resulting from flow‐vegetation interactions is directly linked observed resuspension. observations emphasize role generated by interactions, rather than shear stress mean velocity, main driver array. We test modified Shields parameter analysis, well analytical predictions previously developed unidirectional currents, which accurately predict thresholds oscillatory flow

Language: Английский

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Seasonal Growth and Senescence of a Zostera marina Seagrass Meadow Alters Wave-Dominated Flow and Sediment Suspension Within a Coastal Bay

Estuaries and Coasts, Journal Year: 2013, Volume and Issue: 36(6), P. 1099 - 1114

Published: April 18, 2013

Language: Английский

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INTRODUCTION Eelgrass recovery in the coastal bays of the Virginia Coast Reserve, USA

Marine Ecology Progress Series, Journal Year: 2012, Volume and Issue: 448, P. 173 - 176

Published: Feb. 23, 2012

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 448:173-176 (2012) - DOI: https://doi.org/10.3354/meps09596 INTRODUCTIONEelgrass recovery in coastal bays of Virginia Coast Reserve, USA Robert J. Orth1,*, Karen McGlathery2,** 1Virginia Institute Science, School 1208 Greate Road, College William and Mary, Gloucester Point, 23062, 2Department Environmental Sciences, University Virginia, PO Box 400123, Charlottesville, 22903, *Email: [email protected], **Email: [email protected] ABSTRACT: Coastal bay systems are prominent features coastlines on nearly all continents vulnerable long-term environmental changes related climate nutrient over-enrichment. Eelgrass Zostera marina disappeared 1930s from USA, primarily due a wasting disease effects hurricane. It has been re-established recently as result large-scale seeding restoration effort. The contributions this Theme Section provide most comprehensive account available an eelgrass ecosystem, consequences state change bare-sediment system dominance, projections meadow resilience future scenarios. KEY WORDS: · State Regime shift Full text pdf format Complete PreviousNextCite article as: Orth RJ, McGlathery KJ USA. Mar Ecol Prog Ser 448:173-176. Export citation Tweet linkedIn Cited by Published Vol. 448. Online publication date: February 23, 2012 Print ISSN: 0171-8630; 1616-1599 Copyright © Inter-Research.

Language: Английский

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Depth Affects Seagrass Restoration Success and Resilience to Marine Heat Wave Disturbance

Estuaries and Coasts, Journal Year: 2020, Volume and Issue: 43(2), P. 316 - 328

Published: Jan. 2, 2020

Language: Английский

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