scholarly journals A large invasive consumer reduces coastal ecosystem resilience by disabling positive species interactions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marc J. S. Hensel ◽  
Brian R. Silliman ◽  
Johan van de Koppel ◽  
Enie Hensel ◽  
Sean J. Sharp ◽  
...  
Keyword(s):  
Salt Marshes ◽  
Species Interactions ◽  
Large Scale ◽  
Plant Biomass ◽  
Ecosystem Resilience ◽  
Native Communities ◽  
Southeastern Us ◽  
Recovery Models ◽  
Feral Hogs ◽  
Climatic Disturbances

AbstractInvasive consumers can cause extensive ecological damage to native communities but effects on ecosystem resilience are less understood. Here, we use drone surveys, manipulative experiments, and mathematical models to show how feral hogs reduce resilience in southeastern US salt marshes by dismantling an essential marsh cordgrass-ribbed mussel mutualism. Mussels usually double plant growth and enhance marsh resilience to extreme drought but, when hogs invade, switch from being essential for plant survival to a liability; hogs selectively forage in mussel-rich areas leading to a 50% reduction in plant biomass and slower post-drought recovery rate. Hogs increase habitat fragmentation across landscapes by maintaining large, disturbed areas through trampling of cordgrass during targeted mussel consumption. Experiments and climate-disturbance recovery models show trampling alone slows marsh recovery by 3x while focused mussel predation creates marshes that may never recover from large-scale disturbances without hog eradication. Our work highlights that an invasive consumer can reshape ecosystems not just via competition and predation, but by disrupting key, positive species interactions that underlie resilience to climatic disturbances.

scholarly journals Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes

2020 ◽  
Vol 117 (30) ◽  
pp. 17891-17902 ◽  
Author(s):  
Sinéad M. Crotty ◽  
Collin Ortals ◽  
Thomas M. Pettengill ◽  
Luming Shi ◽  
Maitane Olabarrieta ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
Species Interactions ◽  
Spatial Organization ◽  
Field Experiments ◽  
Keystone Species ◽  
Aerial Image ◽  
Geomorphic Evolution ◽  
Southeastern Us

Keystone species have large ecological effects relative to their abundance and have been identified in many ecosystems. However, global change is pervasively altering environmental conditions, potentially elevating new species to keystone roles. Here, we reveal that a historically innocuous grazer—the marsh crabSesarma reticulatum—is rapidly reshaping the geomorphic evolution and ecological organization of southeastern US salt marshes now burdened by rising sea levels. Our analyses indicate that sea-level rise in recent decades has widely outpaced marsh vertical accretion, increasing tidal submergence of marsh surfaces, particularly where creeks exhibit morphologies that are unable to efficiently drain adjacent marsh platforms. In these increasingly submerged areas, cordgrass decreases belowground root:rhizome ratios, causing substrate hardness to decrease to within the optimal range forSesarmaburrowing. Together, these bio-physical changes provokeSesarmato aggregate in high-density grazing and burrowing fronts at the heads of tidal creeks (hereafter, creekheads). Aerial-image analyses reveal that resulting “Sesarma-grazed” creekheads increased in prevalence from 10 ± 2% to 29 ± 5% over the past <25 y and, by tripling creek-incision rates relative to nongrazed creekheads, have increased marsh-landscape drainage density by 8 to 35% across the region. Field experiments further demonstrate thatSesarma-grazed creekheads, through their removal of vegetation that otherwise obstructs predator access, enhance the vulnerability of macrobenthic invertebrates to predation and strongly reduce secondary production across adjacent marsh platforms. Thus, sea-level rise is creating conditions within whichSesarmafunctions as a keystone species that is driving dynamic, landscape-scale changes in salt-marsh geomorphic evolution, spatial organization, and species interactions.

Towards Control of an Estuary

1987 ◽  
Vol 19 (9) ◽  
pp. 155-174
Author(s):  
Henk L. F. Saeijs
Keyword(s):  
Shallow Water ◽  
Storm Surge ◽  
Salt Marshes ◽  
Large Scale ◽  
Western Europe ◽  
Oxygen Depletion ◽  
Negative Effects ◽  
Intertidal Flats ◽  
Environmental Consequences ◽  
Short Time

The Delta Project is in its final stage. In 1974 it was subjected to political reconsideration, but it is scheduled now for completion in 1987. The final touches are being put to the storm-surge barrier and two compartment dams that divide the Oosterschelde into three areas: one tidal, one with reduced tide, and one a freshwater lake. Compartmentalization will result in 13% of channels, 45% of intertidal flats and 59% of salt marshes being lost. There is a net gain of 7% of shallow-water areas. Human interventions with large scale impacts are not new in the Oosterschelde but the large scale and short time in which these interventions are taking place are, as is the creation of a controlled tidal system. This article focusses on the area with reduced tide and compares resent day and expected characteristics. In this reduced tidal part salt marshes will extend by 30–70%; intertidal flats will erode to a lower level and at their edges, and the area of shallow water will increase by 47%. Biomass production on the intertidal flats will decrease, with consequences for crustaceans, fishes and birds. The maximum number of waders counted on one day and the number of ‘bird-days' will decrease drastically, with negative effects for the wader populations of western Europe. The net area with a hard substratum in the reduced tidal part has more than doubled. Channels will become shallower. Detritus import will not change significantly. Stratification and oxygen depletion will be rare and local. The operation of the storm-surge barrier and the closure strategy chosen are very important for the ecosystem. Two optional closure strategies can be followed without any additional environmental consequences. It was essential to determine a clearly defined plan of action for the whole area, and to make land-use choices from the outset. How this was done is briefly described.

scholarly journals NATURE-BASED COASTAL PROTECTION: WAVE DAMPING BY FLEXIBLE SALT MARSH VEGETATION

2020 ◽  
pp. 9
Author(s):  
Thomas J van Veelen ◽  
Harshinie Karunarathna ◽  
William G Bennett ◽  
Tom P Fairchild ◽  
Dominic E Reeve
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Large Scale ◽  
Coastal Vegetation ◽  
Coastal Protection ◽  
Coastal Zones ◽  
Wave Damping ◽  
Marsh Vegetation ◽  
Efficient Manner ◽  
Wave Energy Dissipation

The ability of coastal vegetation to attenuate waves has been well established (Moller et al., 2014). Salt marshes are vegetated coastal wetlands that can act as nature- based coastal defenses. They exhibit a range of plant species, which have been shown to differ in the amount of wave damping they provide (Mullarney & Henderson, 2018). Recent studies have shown that plant flexibility is a key parameter that controls wave energy dissipation (Paul et al., 2016). Yet, no model exists that includes plant flexibility in computationally efficient manner for large-scale coastal zones. Therefore, we have developed a new model for flexible vegetation based on the key mechanisms in the wave-vegetation interaction and applied it to an estuary with diverse salt marsh vegetation.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/AjnFx3aFSzs

scholarly journals Comorbidities associated with HPV and HSV infections among people living with HIV-1 in the Southeastern US: a retrospective clinical cohort study

2019 ◽  
Author(s):  
Yuanfan Ye ◽  
Greer A. Burkholder ◽  
Howard W. Wiener ◽  
Russell Griffin ◽  
Stella Aslibekyan ◽  
...  
Keyword(s):  
Large Scale ◽  
White Women ◽  
Incidence Rates ◽  
People Living With Hiv ◽  
Anogenital Warts ◽  
Gender And Race ◽  
Clinical Cohort ◽  
Southeastern Us ◽  
Living With Hiv ◽  
Hiv 1

Abstract Background The southeastern US is a domestic epicenter for incident HIV with high prevalence of human papillomavirus (HPV) and herpes simplex virus (HSV) co-infections. However, epidemics of HPV and HSV- associated clinical conditions (CC) among people living with HIV-1 infection (PLWH) are not fully known. Methods Electronic medical records (EMR) of PLWH attending one of the leading HIV clinics in the southeastern US between 2006 and 2018 were reviewed and analyzed. The retrospective study was nested within the University of Alabama at Birmingham HIV clinical cohort, which has electronically collected over 7000 PLWH’s clinical and sociobehavioral data since 1999. Incidence rates of HPV-related CC including anogenital warts, penile, anal, cervical, and vaginal/vulvar low- and high-grade squamous intraepithelial lesions (LSIL and HSIL) and HSV- related CC including anogenital herpetic ulcers were estimated in per 10000 person years. Joinpoint regressions were performed to examine temporal changes in the trends of incident CC. All rates and trends were stratified by gender and race. Results Of the 4,484 PLWH eligible individuals (3,429 men, 1,031 women, and 24 transgender), we observed 1,038 and 425 patients with HPV-and HSV-related CC respectively, and 163 patients with both conditions. The mean log10 viral load (VL) was higher in all of the case groups than the non-cases with neither conditions (5.0) (whereas the median nadir CD4 counts (cells/uL) was higher in the non-cases than in any of the case groups (P<0.05). Anogenital warts, anal LSIL, HSIL, and cancer were more likely to be diagnosed among HIV-infected men than women. White men presented more frequently with anal LSIL and anal and penile cancers than black men (P<0.03). White women were also more likely to be diagnosed with cervical HSIL (P=0.023) and cancer (P=0.037) than black women By contrast, herpetic ulcers were more frequent in women than men. Conclusions There were significant differences between gender and race with incidence of HPV- and HSV-related CC among HIV patients. EMR-based studies provide insights on understudied epidemics; however, large-scale studies in other regions are needed to generalize current findings and draw public health attention to co-infection induced non-AIDS defining comorbidities among PLWH.

Can we improve soil properties and plant biomass using rock powder as soil amendment?

2021 ◽  
Author(s):  
Lena Reifschneider ◽  
Vinzenz Franz Eichinger ◽  
Evelin Pihlap ◽  
Noelia Garcia-Franco ◽  
Anna Kühnel ◽  
...  
Keyword(s):  
Climate Change ◽  
Plant Growth ◽  
Large Scale ◽  
Plant Biomass ◽  
New Mineral ◽  
Severe Drought ◽  
Rock Powder ◽  
Overburden Material ◽  
Neutral Soil ◽  
Mitigate Climate Change

&lt;p&gt;The application of rock powder is an option to improve soil fertility while valorising the overburden material produced by industries. The &amp;#8220;enhanced weathering&amp;#8221; of silicate rock has also gained recent interest in the scientific community for its potential to mitigate climate change. However, the effect of rock powder on the soil physical properties remains unclear, especially under climate change (e.g., increasing drought events). Prior to any large scale application of rock powder, it is crucial to disentangle the potential effects of rock powder application on its environment. In a mesocosm experiment, we explored the effect of three rock powders on plant biomass, soil aggregation and organic carbon (OC) allocation within aggregates, in two soils with clayey and sandy textures, under regular watering or severe drought conditions. We demonstrate that the rock powder was the third factor after drought and soil texture significantly affecting the plant growth, resulting in a significant plant biomass decrease ranging from - 13 % to - 42 % compared with the control. We mainly attribute this effect to the increase of the already neutral soil pH, along with the release of excessive heavy metal amounts at a toxic range for the plant. Yet, we found that adding rock powder to the soil resulted in an increase of the relative amount of microaggregates in the soil by up to + 70 %, along with a re-distribution of OC within the fine fractions of the soil (up to + 32 % of OC in &lt; 250 &amp;#181;m fractions). The new mineral-mineral and organo-mineral interactions promoted by the rock powder addition could potentially favour OC persistence in soil on the long term. With our results, we insist on the potential risks for plant growth associated to the application of rock powder when not handled properly. In addition to the current enthusiasm around the capacity of rock powder to enhance carbon sequestration in the inorganic form, we also encourage scientists to focus their research on its effect on soil structure properties and OC storage.&lt;/p&gt;

Benthic species as mud patrol - modelled effects of bioturbators and biofilms on large-scale estuarine mud and morphology

2021 ◽  
Author(s):  
Muriel Brückner ◽  
Christian Schwarz ◽  
Giovanni Coco ◽  
Anne Baar ◽  
Márcio Boechat Albernaz ◽  
...  
Keyword(s):  
Morphological Change ◽  
Species Interactions ◽  
Large Scale ◽  
Habitat Degradation ◽  
Species Abundance ◽  
Estuarine Sediments ◽  
Morphological Development ◽  
Benthic Species ◽  
Species Dominance ◽  
Species Specific

&lt;p&gt;Benthic species that live within estuarine sediments stabilize or destabilize local mud deposits through their eco-engineering activities, affecting the erosion of intertidal sediments. Possibly, the altered magnitudes in eroded sediment affect the large-scale redistribution of fines and hence morphological change. To quantify this biological control on the morphological development of estuaries, we numerically model i) biofilms, ii) two contrasting bioturbating species present in NW-Europe, and iii) their combinations by means of our novel eco-morphodynamic model. The model predicts local mud erodibility based on species pattern, which dynamically evolves from the hydrodynamics, soil mud content, competition and grazing, and is fed back into the hydromorphodynamic computations.&lt;/p&gt;&lt;p&gt;We find that biofilms reduce mud erosion on intertidal floodplains and stabilize estuarine morphology, whereas the two bioturbators significantly enhance inter- and supratidal mud erosion and bed elevation change, leading to a large-scale reduction in deposited mud and a widening of the estuary. In turn, the species-dependent changes in mud content redefines their habitat and leads to a redistribution of species abundances. Here, the eco-engineering affects habitat conditions and species abundance while species interactions determine species dominance. Our results show that species-specific biostabilization and bioturbation determine large-scale morphological change through mud redistribution, and at the same time affect species distribution. This suggests that benthic species have subtly changed estuarine morphology through space and time and that aggravating habitat degradation might lead to large effects on the morphology of future estuaries.&lt;/p&gt;

scholarly journals Plants: biofactories for a sustainable future?

2011 ◽  
Vol 369 (1942) ◽  
pp. 1826-1839 ◽  
Author(s):  
Thomas Jenkins ◽  
Aurélie Bovi ◽  
Robert Edwards
Keyword(s):  
Organic Carbon ◽  
Large Scale ◽  
Plant Biomass ◽  
Biofuel Production ◽  
Scale Production ◽  
Edible Plant ◽  
Oil Reserves ◽  
Optimal Processing ◽  
Large Scale Production ◽  
Food Applications

Depletion of oil reserves and the associated effects on climate change have prompted a re-examination of the use of plant biomass as a sustainable source of organic carbon for the large-scale production of chemicals and materials. While initial emphasis has been placed on biofuel production from edible plant sugars, the drive to reduce the competition between crop usage for food and non-food applications has prompted massive research efforts to access the less digestible saccharides in cell walls (lignocellulosics). This in turn has prompted an examination of the use of other plant-derived metabolites for the production of chemicals spanning the high-value speciality sectors through to platform intermediates required for bulk production. The associated science of biorefining, whereby all plant biomass can be used efficiently to derive such chemicals, is now rapidly developing around the world. However, it is clear that the heterogeneity and distribution of organic carbon between valuable products and waste streams are suboptimal. As an alternative, we now propose the use of synthetic biology approaches to ‘re-construct’ plant feedstocks for optimal processing of biomass for non-food applications. Promising themes identified include re-engineering polysaccharides, deriving artificial organelles, and the reprogramming of plant signalling and secondary metabolism.

scholarly journals A Global Synthesis Reveals Gaps in Coastal Habitat Restoration Research

2018 ◽  
Vol 10 (4) ◽  
pp. 1040 ◽  
Author(s):  
Y. Zhang ◽  
William Cioffi ◽  
Rebecca Cope ◽  
Pedro Daleo ◽  
Eleanor Heywood ◽  
...  
Keyword(s):  
Salt Marshes ◽  
Species Interactions ◽  
Habitat Restoration ◽  
Experimental Studies ◽  
Coastal Ecosystems ◽  
Marine Conservation ◽  
Coastal Habitat ◽  
Coastal Restoration ◽  
Vote Count ◽  
Abiotic And Biotic Factors

Coastal ecosystems have drastically declined in coverage and condition across the globe. To combat these losses, marine conservation has recently employed habitat restoration as a strategy to enhance depleted coastal ecosystems. For restoration to be a successful enterprise, however, it is necessary to identify and address potential knowledge gaps and review whether the field has tracked scientific advances regarding best practices. This enables managers, researchers, and practitioners alike to more readily establish restoration priorities and goals. We synthesized the peer-reviewed, published literature on habitat restoration research in salt marshes, oyster reefs, and seagrasses to address three questions related to restoration efforts: (i) How frequent is cross-sector authorship in coastal restoration research? (ii) What is the geographic distribution of coastal restoration research? and (iii) Are abiotic and biotic factors equally emphasized in the literature, and how does this vary with time? Our vote-count survey indicated that one-third of the journal-published studies listed authors from at least two sectors, and 6% listed authors from all three sectors. Across all habitat types, there was a dearth of studies from Africa, Asia, and South America. Finally, despite many experimental studies demonstrating that species interactions can greatly affect the recovery and persistence of coastal foundation species, only one-fourth of the studies we examined discussed their effects on restoration. Combined, our results reveal gaps and discrepancies in restoration research that should be addressed in order to further propel coastal restoration science.

scholarly journals Large-scale predictions of salt-marsh carbon stock based on simple observations of plant community and soil type

2019 ◽  
Vol 16 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Hilary Ford ◽  
Angus Garbutt ◽  
Mollie Duggan-Edwards ◽  
Jordi F. Pagès ◽  
Rachel Harvey ◽  
...  
Keyword(s):  
Plant Community ◽  
Salt Marshes ◽  
Soil Type ◽  
Carbon Stock ◽  
Large Scale ◽  
Coastal Wetland ◽  
Blue Carbon ◽  
Wetland Ecosystems ◽  
Soc Stock ◽  
Carbon Store

Abstract. Carbon stored in coastal wetland ecosystems is of global relevance to climate regulation. Broadscale inventories of this “blue” carbon store are currently lacking and labour intensive. Sampling 23 salt marshes in the United Kingdom, we developed a Saltmarsh Carbon Stock Predictor (SCSP) with the capacity to predict up to 44 % of spatial variation in surface soil organic carbon (SOC) stock (0–10 cm) from simple observations of plant community and soil type. Classification of soils into two types (sandy or not-sandy) explained 32 % of variation in SOC stock. Plant community type (five vegetation classes) explained 37 % of variation. Combined information on soil and plant community types explained 44 % of variation in SOC stock. GIS maps of surface SOC stock were produced for all salt marshes in Wales (∼4000 ha), using existing soil maps and governmental vegetation data and demonstrating the application of the SCSP for large-scale predictions of blue carbon stores and the use of plant community traits for predicting ecosystem services.

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