Restoration of tidal freshwater vegetation using controlled reduced tide (CRT) along the Schelde Estuary (Belgium)
TL;DR: In this article, controlled reduced tide (CRT) was used to restore tidal freshwater marsh habitat in an agricultural site where elevation relative to the estuarine marshes has been lowered.
Abstract: Throughout the world, tidal marshes are being restored to obtain natural protection against recurring storm surges and sea level rise and to preserve the resources these habitats provide. Managed realignment, or breaching of the seaward dikes, is a restoration technique increasingly used; yet unsuitable site elevation has been a major constraint to habitat development. Controlled reduced tide (CRT), a new technique to implement tidal regime on low elevated sites, could offer solutions for several problems associated with reconstruction or mitigation of tidal marshes. We followed vegetation development at 3-month intervals during two years after implementation of the first pilot CRT treatment, which aimed to restore tidal freshwater marsh habitat in an agricultural site where elevation relative to the estuarine marshes has lowered. The development of the plant community and its driving forces (flooding, remnant vegetation) were studied. Arrival and establishment of typical tidal freshwater marsh vegetation was rapid, and a clear elevation gradient developed by eradication of terrestrial species and colonisation by estuarine species. Remnant vegetation substantially reduced the number of new established species. General development trajectory as well as the changing effect of driving forces and their interaction point to a swift ecosystem shift during the first two surveys, and a gradual species saturation during the seven following surveys. Vegetation communities seem to deviate from the nearby tidal freshwater marshes, but show similarities with tidal freshwater marshes described for the beginning of the 20th century. The CRT-technique provides strong potential for durable, adaptive restoration of tidal marshes on sites with low elevation. Wider implementation of the CRT technique could increase the total surface of tidal freshwater marshes with fully developed vegetation gradients.
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TL;DR: In this article, the authors illustrate a typology of 14 natural and anthropogenic hazards, the evidence for their causes and consequences for society and their role as vectors of change in estuaries, vulnerable coasts and marine areas.
102 citations
TL;DR: In this article, the authors compared the long-term change in elevation (ΔE) within a restored CRT marsh and adjacent natural tidal marsh and found that the observed spatio-temporal variations in ΔE rate were related to variations in inundation depth.
72 citations
Cites background from "Restoration of tidal freshwater veg..."
...Organic matter accumulation can be expected to differ between the CRT sites and the natural tidal marsh due to the different vegetation species and colonization times (Jacobs et al., 2009)....
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...2C), and the differences in vegetation cover and thus organic accumulation rate (pioneer vegetation in CRT, climax vegetation in natural tidal marsh (Jacobs et al., 2009)), no significant differences are observed between ΔE in the CRT marsh and the natural tidal marsh (Fig....
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...This is important for the restoration of tidal marshes along the Scheldt estuary: a platform elevation belowMHWL implies the restoration of typical lower marshes, which is a habitat that is scarce along the Scheldt estuary (Jacobs et al., 2009)....
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...In the natural tidal marsh, the tidal freshwater vegetation already reached a climax state, while on the CRT marsh pioneer vegetation prevails (Jacobs et al., 2009)....
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TL;DR: In this paper, the spontaneous formation and evolution of a tidal channel network in a newly constructed tidal marsh (Scheldt estuary, Belgium) over a period of 4 years, by high-accuracy topographic surveying with a temporal resolution of 1 year at high spatial resolution considering all channels deeper than 0.1 m.
66 citations
TL;DR: Mallen-Cooper et al. as discussed by the authors describe a Fishway Consulting Services, 8 Tudor Pl, St Ives Chase, 2075, NSW, Australia, Australia. Email: mallencooper@optusnet.com.au
Abstract: Fishway Consulting Services, NSW, Australia 2 Institute for Land, Water and Society, Charles Sturt University, NSW, Australia 3 Inland Waters and Catchment Ecology Program, SARDI Aquatic Sciences, SA, Australia School of Biological Sciences, The University of Adelaide, SA, Australia Correspondence Martin Mallen‐Cooper, Fishway Consulting Services, 8 Tudor Pl, St Ives Chase, 2075, NSW, Australia. Email: mallencooper@optusnet.com.au
56 citations
Cites background from "Restoration of tidal freshwater veg..."
...In concert, operating the tidal barrages to be more permeable, allowing exchange of seawater and freshwater—similar to the growing trend in tidal floodgates (Boys & Pease, 2017; Jacobs et al., 2009)—may assist in restoring estuarine function in this highly regulated river system....
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Book•
14 Jul 2014
TL;DR: Managed realignment is a relatively new soft engineering alternative aiming to provide sustainable flood risk management with added environmental and socio-economic benefits by creating space for coastal habitats to develop more dynamically as mentioned in this paper.
Abstract: Climate change and environmental and financial concerns have led to a shift from the traditional ‘hold-the-line’ approach of coastal protection towards more flexible soft engineering options. Managed realignment is a coastal management strategy increasingly implemented in Europe and other countries worldwide. It is a relatively new soft engineering alternative aiming to provide sustainable flood risk management with added environmental and socio-economic benefits by creating space for coastal habitats to develop more dynamically. The natural adaptive capacity of coastal habitats and the delivery of ecosystem services underpin the sustainability of managed realignment. However, many definitions of managed realignment exist and the understanding of what the term actually represents in practice has evolved through time and varies regionally. This book clarifies the definitions and terminology used in the literature and proposes that managed realignment is used as a general term that encompasses the many different methods of implementation worldwide, including: removal, breach and realignment of defences; controlled tidal restoration ; and managed retreat. These methods of implementation are explained and illustrated with examples from around the world. In addition to a general overview of emerging policies and current practices, specific chapters discuss approaches adopted in the Netherlands, the UK and Maui (US). The UK experience is presented from the perspectives of three sectors: the National Trust (a charity that owns 10% of England’s coastline), the Environment Agency (a government organisation responsible for implementing flood and erosion risk policy) and a private consultant involved in the design and delivery of managed realignment projects. Recent national and regional strategies worldwide give managed realignment an increasing role in climate change and flood risk management. Gaining stakeholders and public support is fundamental for the success of emerging coastal management strategies. However, public perception and stakeholders engagement are often cited as a factor limiting the wider uptake of managed realignment. Results from a recent survey are used to benchmark the current thinking about the potential, the performance and the limitations of managed realignment in the UK and elsewhere. The views of stakeholders are considerably more negative and notably contrast with the views of practitioners and researchers. The only clear and dominant agreement across all groups of respondents is that better understanding about the long-term evolution of sites is needed. Taking a wider perspective to consider the range of implementation methods, the viability of managed realignment as a long-term coastal management strategy is discussed.
54 citations
Cites methods from "Restoration of tidal freshwater veg..."
...Controlled reduced tide (CRT) is an approach similar to RTE, more widely applied in Belgium to describe the use of carefully designed sluices to control tidal flows within FCAs with the objective of promoting intertidal habitat development (Cox et al., 2006; Maris et al., 2007; Jacobs et al., 2009; Vandenbruwaene et al., 2011; Beauchard et al., 2011, 2013)....
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References
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Book•
01 Jan 1991
TL;DR: This book discusses the construction of tests in non-standard situations testing for randomness of species co-occurences on islands examining time change in niche ovelap probing multivariate data with random skewers other examples.
Abstract: Part 1 Randomization tests and confidence intervals: the idea of a randomization test examples of a randomization test aspects of randomization testing raised by the examples confidence intervals from randomization. Part 2 Monte Carlo and other computer intensive methods: Monte Carlo tests jackknifing bootstrapping bootstrap tests of significance and confidence intervals. Part 3 Some general considerations: power determining how many randomizations are needed determining a randomization distribution exactly the computer generation of pseudo-random numbers generating random permutations. Part 4 One and two sample tests: the paired comparisons design the one sample randomization test the two sample randomization test the comparison of two samples on multiple measurements. Part 5 Analysis of variance: one factor analysis of variance Bartlett's test for constant variance examples of more complicated types of analysis of variance discussion computer program. Part 6 Regrssion analysis: simple regression testing for a non-zero beta value confidence limits for beta multiple linear regression randomizing X variable values. Part 7 Distance matrices and spatial data: testing for association between distance matrices Mantel's test determining significance by sampling randomization distribution confidence limits for a matrix regression coefficient problems involving more than two matrices. Part 8 Other analyses on spatial data: the study of spatial point patterns Mead's randomization test a test based on nearest neighbour distances testing for an association between two point patterns the Besag-Diggle test tests using distances between points. Part 9 Time series: randomization and time series randomization tests for serial correlation randomization tests for trend randomization tests for periodicity irregularly spaced series tests on times of occurence discussion of procedures for irregular series bootstrap and Monte Carlo tests. Part 10 Multivariate data: univariate and multivariate tests sample means and covariance matrices comparison on sample means vectors chi-squared analyses for count data principal component analysis and other one sample methods discriminate function analysis. Part 11 Ad hoc methods: the construction of tests in non-standard situations testing for randomness of species co-occurences on islands examining time change in niche ovelap probing multivariate data with random skewers other examples. Part 12 Conclusion: randomization methods bootstrap and Monte Carlo methods.
1,705 citations
1,618 citations
"Restoration of tidal freshwater veg..." refers background in this paper
...Moreover, the helophyte community, which is the dominant plant life-form for all known tidal freshwater marshes (Ellenberg, 1963; Struyf et al., 2009) completely deviates from the present marsh vegetations in the Schelde....
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Cornell University1, Université libre de Bruxelles2, United States Environmental Protection Agency3, Oregon State University4, Iowa State University5, Stockholm University6, Smithsonian Institution7, Wageningen University and Research Centre8, Commonwealth Scientific and Industrial Research Organisation9, United States Geological Survey10
TL;DR: In this paper, the authors present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North America, South America, Europe, and Africa which collectively comprise the drainage basins to North Atlantic.
Abstract: We present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North America, South America, Europe, and Africa which collectively comprise the drainage basins to the North Atlantic. The Amazon basin dominates the overall phosphorus flux and has the highest phosphorus flux per area. The total nitrogen flux from the Amazon is also large, contributing 3.3 Tg yr-1 out of a total for the entire North Atlantic region of 13.1 Tg yr-1. On a per area basis, however, the largest nitrogen fluxes are found in the highly disturbed watersheds around the North Sea, in northwestern Europe, and in the northeastern U.S., all of which have riverine nitrogen fluxes greater than 1,000 kg N km-2 yr-1.
1,614 citations
"Restoration of tidal freshwater veg..." refers background in this paper
...Their role in estuarine biogeochemistry has been studied and reviewed intensively in recent decades (e.g. Dame et al., 1986; Howarth et al., 1996), emphasising their role in C, N and P transformations (e.g. Spurrier and Kjerfve, 1988; Childers and Day, 1988; Gribsholt et al., 2005) and in the…...
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...Their role in estuarine biogeochemistry has been studied and reviewed intensively in recent decades (e.g. Dame et al., 1986; Howarth et al., 1996), emphasising their role in C, N and...
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01 Jan 2004
1,195 citations
"Restoration of tidal freshwater veg..." refers methods in this paper
...All computations and associated graphical representations were implemented using the ade4 package (Chessel et al., 2004) available in R freeware (R, 2008)....
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Journal Article•
TL;DR: In this article, the authors present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North America, South America, Europe, and Africa which collectively comprise the drainage basins to the Atlantic Ocean.
Abstract: We present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North America, South America, Europe, and Africa which collectively comprise the drainage basins to the North Atlantic. The Amazon basin dominates the overall phosphorus flux and has the highest phosphorus flux per area. The total nitrogen flux from the Amazon is also large, contributing 3.3 Tg yr−1 out of a total for the entire North Atlantic region of 13.1 Tg yr−1 . On a per area basis, however, the largest nitrogen fluxes are found in the highly disturbed watersheds around the North Sea, in northwestern Europe, and in the northeastern U.S., all of which have riverine nitrogen fluxes greater than 1,000 kg N km−2 yr−1.Non-point sources of nitrogen dominate riverine fluxes to the coast in all regions. River fluxes of total nitrogen from the temperate regions of the North Atlantic basin are correlated with population density, as has been observed previously for fluxes of nitrate in the world's major rivers. However, more striking is a strong linear correlation between river fluxes of total nitrogen and the sum of anthropogenically-derived nitrogen inputs to the temperate regions (fertilizer application, human-induced increases in atmospheric deposition of oxidized forms of nitrogen, fixation by leguminous crops, and the import/export of nitrogen in agricultural products). On average, regional nitrogen fluxes in rivers are only 25% of these anthropogenically derived nitrogen inputs. Denitrification in wetlands and aquatic ecosystems is probably the dominant sink, with storage in forests perhaps also of importance. Storage of nitrogen in groundwater, although of importance in some localities, is a very small sink for nitrogen inputs in all regions. Agricultural sources of nitrogen dominate inputs in many regions, particularly the Mississippi basin and the North Sea drainages. Deposition of oxidized nitrogen, primarily of industrial origin, is the major control over river nitrogen export in some regions such as the northeastern U.S.Using data from relatively pristine areas as an index of change, we estimate that riverine nitrogen fluxes in many of the temperate regions have increased from pre-industrial times by 2 to 20 fold, although some regions such as northern Canada are relatively unchanged. Fluxes from the most disturbed region, the North Sea drainages, have increased by 6 to 20 fold. Fluxes from the Amazon basin are also at least 2 to 5 fold greater than estimated fluxes from undisturbed temperate-zone regions, despite low population density and low inputs of anthropogenic nitrogen to the region. This suggests that natural riverine nitrogen fluxes in the tropics may be significantly greater than in the temperate zone. However, deforestation may be contributing to the tropical fluxes. In either case, projected increases in fertilizer use and atmospheric deposition in the coming decades are likely to cause dramatic increases in nitrogen loading to many tropical river systems.
494 citations