The “ReDune” index (Restoration of coastal Dunes Index) to assess the need and viability of coastal dune restoration

2015 ◽  
Vol 49 ◽  
pp. 178-187 ◽  
Author(s):  
Debora Lithgow ◽  
M. Luisa Martínez ◽  
Juan B. Gallego-Fernández
1997 ◽  
Vol 75 (6) ◽  
pp. 902-915 ◽  
Author(s):  
Gilles Houle

Coastal dunes are very dynamic systems, particularly where the coast is rising as a result of isostatic rebound. In those environments, succession proceeds from plants highly tolerant to sand accumulation, salt spray, and low nutrient availability to less disturbance-tolerant and stress-tolerant, more nutrient-demanding, and supposedly more competitive species. In the subarctic, the regional climate exacerbates the stresses imposed by local abiotic conditions on the dunes. I hypothesized that facilitation would be particularly significant on the foredune of subarctic coastal dune systems because of intense stresses (local and regional) and frequent disturbance in the form of sand deposition. Belowground and aboveground plant biomass was sampled at three different periods during the 1990 growing season along transects perpendicular to the shoreline on a coastal dune system in subarctic Quebec (Canada). The three herbaceous perennials found on the foredune (Honckenya peploides, Elymus mollis, and Lathyrus japonicus) were segregated in time during the growing season and in space along the topographical gradient. The biomass of Honckenya, the first species encountered as one progresses from the upper part of the beach towards the foredune ridge, was not correlated to substrate physicochemistry. However, the biomass of Elymus and that of Lathyrus, the next two species to appear along the flank of the foredune, were related to pH, Mg, Na, and Cl (negatively), and to P and Ca (positively). These results suggest variable linkages between substrate physicochemistry and plant species along the foredune, possibly in relation to species-specific tolerance for abiotic conditions and requirements for substrate resources or to microscale influence of the plants themselves on substrate physicochemistry. Removal experiments carried out over 2 years revealed only one significant unidirectional interaction between these three species along the topographical gradient, and little plant control over abiotic variables (e.g., soil temperature, wind velocity, and photosynthetically active radiation). Early primary succession on subarctic coastal dunes (and elsewhere) appears to be under the control of strong limiting abiotic conditions. As plants slowly gain more control over the physical environment, interspecific interactions (positive and negative) may become more significant. Key words: Elymus mollis, facilitation, Honckenya peploides, inhibition, Lathyrus japonicus, removal experiment, succession, tolerance.


2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Ana Novoa ◽  
Jan-Hendrik Keet ◽  
Yaiza Lechuga-Lago ◽  
Petr Pyšek ◽  
Johannes J Le Roux

ABSTRACT Coastal dunes are ecosystems of high conservation value that are strongly impacted by human disturbances and biological invasions in many parts of the world. Here, we assessed how urbanization and Carpobrotus edulis invasion affect soil bacterial communities on the north-western coast of Spain, by comparing the diversity, structure and composition of soil bacterial communities in invaded and uninvaded soils from urban and natural coastal dune areas. Our results suggest that coastal dune bacterial communities contain large numbers of rare taxa, mainly belonging to the phyla Actinobacteria and Proteobacteria. We found that the presence of the invasive C. edulis increased the diversity of soil bacteria and changed community composition, while urbanization only influenced bacterial community composition. Furthermore, the effects of invasion on community composition were conditional on urbanization. These results were contrary to predictions, as both C. edulis invasion and urbanization have been shown to affect soil abiotic conditions of the studied coastal dunes in a similar manner, and therefore were expected to have similar effects on soil bacterial communities. Our results suggest that other factors (e.g. pollution) might be influencing the impact of urbanization on soil bacterial communities, preventing an increase in the diversity of soil bacteria in urban areas.


2020 ◽  
Vol 44 (6) ◽  
pp. 814-836 ◽  
Author(s):  
Jinjuan Gao ◽  
David M Kennedy ◽  
Teresa M Konlechner

The mobility of coastal dunes is characterised by bio-geomorphological responses related to change in boundary conditions, particularly sediment supply, wind and vegetation cover, as well as human activities. There remains uncertainty regarding the relative importance of these drivers on dune mobility at a global scale. In this study, trends and dominant drivers of coastal dune mobility are synthesised through the literature review focusing on shifts in dune mobility over the last century (1870–2018). In total, 176 individual dunes, with 55 dunes from the Europe-Mediterranean area, 23 from Africa, 30 from North America, 23 from South America, 20 from Oceania and 23 from Asia, are reviewed in this work. The results show that there is a worldwide trend of dune stabilisation, with 93% (164 out of 176) of the reviewed sites showing a loss of bare sand area due to an increase in vegetation cover and urbanisation expansion. Multiple factors have contributed to the stabilisation process, including (a) land-use change such as the change of traditional farming practises, coastal urbanisation and tourism development; (b) dune stabilisation projects; (c) sediment decline caused by the riverine and coastal constructions; and (d) change in climate (i.e. the decrease in windiness, and the increase in temperature and rainfall) and storms. Our results suggest human intervention played a dominant role in altering dune mobility for most dunes during the past century, while climate and storms are also important drivers, especially for dune sites with limited human activities.


2020 ◽  
Author(s):  
Mihaela Tudor ◽  
Ana Ramos-Pereira ◽  
Joana Gaspar de Freitas

<p>Coastal dunes are very complex systems and very sensitive to climatic variability and human actions. In Portugal, coastal dune fields have undergone major changes over historical times. The aim of the paper is focused on the coastal dune systems evolution over the last five centuries, natural and man induced (namely by deforestation and afforestation) and their transformation under the present global changes (sea level rise and coastal storms). The analysis of historical records and environmental data using a set of proxies recorded over the last 1,000 yrs, show intense aeolian activity and sand drift episodes during Little Age Period, causing serious problems for human settlements and agriculture. Coastal society have responded to the wind-blown sands fixing the dunes through afforestation. The process is well documented in the historical sources and many management measures, including abundant legislation, projects and reports were carried out by Portuguese authorities to avoid sand incursion inland.  According to the main report of the General Forest Administration, in the final of 18th century, was estimated an area of about 72 000 ha of free aeolian sands in need of afforestation. Thus, along Portuguese coastline, the dunes experienced a period of stability during the 20th century, due to planting of grasses and pine forest. This paper examines the pathways of the transgressive dune fields of the Central Western Portuguese coast, over various stages of coastal evolution. Mapping the morphological features between Mondego river mouth and Nazaré, using a combination of satellite images, aerial photographs and Lidar data we identified distinct phases of aeolian activity and landforms modification that were associated to climatic fluctuations. This coastal dune system is composed by a succession of different aeolian phases, including a littoral foredune, which lies inland with a complexity of morphologies with transverse and crescentic ridges, and also parabolic dunes. The results show that the dunes building and sand migration inland appears to be linked to the conditions of predominantly negative winter North Atlantic Oscillation index (NAOi), driven by climatic variability during Holocene/Antrhopocene. The consistency of intense sand drift episodes with abrupt cold events during Little Age Period, drastically reduced the area occupied by vegetation, causing changes in aeolian sedimentary processes. Thus, it seems that coastal dunes evolution over the past centuries have been controlled by the two-way interactions between natural conditions and human activities, shaping the Portuguese coastline. Placing historical evidence in a geographical perspective, we hope to fill the gaps in coastal zone dynamics, providing new insights of the human-landscape relationships to predict the future response of the coastal dune systems to human pressure and climate change.<br>Key-words: coastal dunes evolution, geomorphological features, sand drift, anthropogenic impacts, climatic fluctuation, Western Portugal.</p>


EDIS ◽  
2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Debbie Miller ◽  
Mack Thetford ◽  
Chris Verlinde ◽  
Gabriel Campbell ◽  
Ashlynn Smith

Gopher apple occurs from the lower Florida peninsula northward to South Carolina westward to Louisiana in coastal dunes, sandhills, and disturbed areas such as roadsides. Gopher apple gets its name because gopher tortoises, along with other small mammals, eat their fruit. Gopher apple is an ideal groundcover for a coastal landscape with well-draining soil and a low pH (Gilman 2014).https://edis.ifas.ufl.edu/sg169 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle,  Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques


Geomorphology ◽  
2013 ◽  
Vol 199 ◽  
pp. 214-224 ◽  
Author(s):  
D. Lithgow ◽  
M.L. Martínez ◽  
J.B. Gallego-Fernández ◽  
P.A. Hesp ◽  
P. Flores ◽  
...  

2020 ◽  
Author(s):  
Thomas Smyth ◽  
Ryan Wilson ◽  
Paul Rooney ◽  
Katherine Yates

<p>Coastal dunes are dynamic landforms whose morphology is governed primarily by climate and vegetation dynamics. Over the last 50 years, coastal sand dunes across the globe have dramatically ‘greened’ and wind speeds fallen (Pye et al., 2014; Delgado-Fernandez et al., 2019; Jackson et al., 2019), reducing aeolian transport of sediment and minimising dune reshaping by near-surface winds.  This rapid vegetation has also been attributed to a dramatic decline of several rare species of plants and invertebrates in several coastal dune systems (Howe et al., 2010; Pye et al., 2014). In an effort to increase habitat diversity, large-scale vegetation removal and dune re-profiling are becoming increasingly common interventions. However sustained aeolian activity following intervention appears to be rare (Arens et al., 2013).</p><p>In order to better understand the environmental drivers of long-term dune mobility, this work explores the landscape scale physical factors related to self-sustaining ‘natural’ mobile dunes across the United Kingdom. The analysis presented includes the use of geographically weighted regression, a spatial analysis technique that models the local relationships between predictors (e.g. wind speed, slope, elevation, aspect, surface roughness) and an outcome of interest (mobile dunes). It is hoped that the results of this work will help guide decision-making with regards the location, scale and morphology of future interventions in order to maximise their sustainability, minimising the need for maintenance and further intervention.</p><p>References</p><p>Arens, S.M., Slings, Q.L., Geelen, L.H. and Van der Hagen, H.G., 2013. Restoration of dune mobility in the Netherlands. In Restoration of coastal dunes (pp. 107-124). Springer, Berlin, Heidelberg.</p><p>Delgado-Fernandez, I., O'Keeffe, N., & Davidson-Arnott, R. G. (2019). Natural and human controls on dune vegetation cover and disturbance. Science of The Total Environment, 672, 643-656.</p><p>Howe, M. A., Knight, G. T., & Clee, C. (2010). The importance of coastal sand dunes for terrestrial invertebrates in Wales and the UK, with particular reference to aculeate Hymenoptera (bees, wasps & ants). Journal of Coastal Conservation, 14(2), 91-102.</p><p>Jackson, D. W., Costas, S., González-Villanueva, R., & Cooper, A. (2019). A global ‘greening’of coastal dunes: An integrated consequence of climate change?. Global and Planetary Change, 182, 103026.</p><p>Pye, K., Blott, S. J., & Howe, M. A. (2014). Coastal dune stabilization in Wales and requirements for rejuvenation. Journal of coastal conservation, 18(1), 27-54.</p>


Baltica ◽  
2018 ◽  
Vol 30 (2) ◽  
pp. 106-97 ◽  
Author(s):  
Jacek Tylkowski

The study looked at the temporal and spatial variability of dune erosion in the Polish Baltic coastal zone in the period 1972–2008. The dynamics of coastal dune erosion in the area are presented in relationship to the main hydro-meteorological factors: storm surges and types of atmospheric circulation. The greatest destruction of the coastal dunes in Poland was observed on sandbar sections, where the erosion was over 100,000 m3 per 1 km, causing dune baseline retreat by several tens of meters. The main causes of this considerable coastal erosion are the sudden rise of the sea level and the waves during extreme storm surges, when the loss of dune sediment across the entire Polish Baltic Sea coastal zone can reach about 400,000 m3. These extremely erosive storm surges are particularly generated by cyclonic atmospheric circulation, which accounts for more than 52% of such surges from the north-west, north, and west. It was also found that sea level increases of more than 1 meter (about 602 cm) above the mean sea level (about 500 cm) can result in significant erosion of coastal dunes in Poland (>100,000 m3). However, there is a relationship between the intensity of the dune erosion and sea level. The results of the present study could be applied to studies of Baltic coastal dunes functioning in the lagoon-spit coastline, especially in the stretch from Estonia to Germany.


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