Dune Vegetation Research Articles

Historical Coastal Evolution and Dune Vegetation in Isla Salamanca National Park, Colombia

ABSTRACT Gomez, J.F.; Byrne, M.-L.; Hamilton, J., and Isla, F., 2017. Historical coastal evolution and dune vegetation in Isla Salamanca National Park, Colombia. This paper analyzes the relationship between coastal dynamics and vegetation over dunes in Isla Salamanca Road Park (ISRP), a biosphere reserve and Ramsar site located on the Colombian Caribbean coast. Historical coastline changes together with the main geomorphological features were surveyed through fieldwork, satellite images, and historical aerial photographs, revealing that erosion is the predominant process in the eastern and central sectors of ISRP, and accreting trends throughout time occur in the westernmost sector of the study area. Dunes in the central and eastern sectors are scarped and regularly affected by storm wave action, whereas on the western end of the study area, embryo dunes are currently forming and evolving. Based on the mapped landforms and coastline trends for the last six decades, 1-square-m quadrats were used to identif...

Activity and short-term impacts of dromedary camels (Camelus dromedarius) foraging on perennial coastal sand dune vegetation

Previous studies have demonstrated the camels’ (1) dietary preference for perennial plants, (2) low selectivity among perennial species, and (3) ability to remove large amounts of perennial biomass, thus causing irreversible damage on the landscape. We studied the activity and feeding behaviour of camels on coastal sand dunes dominated by the dwarf shrub Artemisia monosperma, as well as the short-term impacts of camel foraging on perennial vegetation. The herd foraged on four semi-stabilised dunes during summer, when the available biomass was composed almost entirely of perennials. We recorded the activity and feeding selectivity of the camels, as well as the consumption and recovery of the common perennial plant species. The camels were selective foragers and spent relatively little time feeding when the more palatable perennial species became scarcer. Most of the more palatable (herbaceous) species were consumed, and these plant species recovered faster and more abundantly than the less palatable (both woody and herbaceous) species, which were hardly consumed. A. monosperma was practically avoided despite its dominance, even when more palatable species were nearly absent. In conclusion, results suggest that camels are selective feeders, and will not cause irreversible damage to the local vegetation.

Temporal changes in the vegetation of Italian coastal dunes: identifying winners and losers through the lens of functional traits

Summary Plant communities of coastal dunes are highly biodiverse and greatly valued for the services they provide, yet they are also threatened by global change and are often neglected in conservation planning. To determine the long‐term effectiveness of conservation actions on Mediterranean coastal dunes, here we focus on Italy's coastline and (i) assess how the vegetation cover of the major psammophilous habitats and species has changed since the 1960s, (ii) identify which ecological strategies have been most successful in the face of global change and (iii) evaluate the efficacy of the protected areas network for safeguarding plant communities of coastal dunes. We compiled 2583 geo‐located vegetation relevés spanning over half a century and covering the entire length of Italy's sandy coastline. Using this data base, we developed statistical models to test whether the vegetation cover of both individual species and habitats has changed over time. We then tested whether species‐level changes in vegetation cover through time could be explained by species’ functional traits and ecological strategy. Finally, we assessed the efficacy of current conservation measures by exploring how vegetation cover responded following the expansion of the protected areas network. Our results indicate that, where protected, plant communities have generally increased in vegetation cover in recent years. The strongest increase in cover occurred in the wooded dune habitats, where late‐successional, tall‐growing and large‐seeded species show the clearest signs of recovery. However, this has come in part at the expense of dune grasslands, which thrive under natural disturbance and have declined since the 1960s. The Natura 2000 network seems to have played a central role in this recovery process, as the cumulative coastal land area under protection has tripled since the network was first established. Synthesis and applications. Our results suggest that protected areas can play an important role in safeguarding coastal dune plant communities against land‐use transformations. In this context, functional traits can be a powerful tool in guiding conservation planning, helping to identify groups of species most at risk of population declines. Nonetheless, future conservation interventions need to be mindful to ensure that the natural disturbance regime of dune ecosystems is not disrupted.

Priority areas for conservation of beach and dune vegetation of the Mexican Atlantic coast

We modeled the potential distribution of plant species that grow on the beaches and dunes of the Mexican Atlantic coast in order to identify areas of high biodiversity. We used environmental layers in combination with georeferenced data, utilizing the MaxEnt algorithm, and produced four regional consensus maps according to the geographic distribution of the species: along the entire Mexican Atlantic coast, the Gulf of Mexico; the Yucatan Peninsula and all species combined together on a single map. The largest number of widely distributed species in the Gulf of Mexico was concentrated in the northern and central regions, while biodiversity on the Yucatan Peninsula was likely to be concentrated in the north and on Cozumel island, which is the biggest island in the Mexican Caribbean. The map combining all species together revealed a potential concurrence of species in the Gulf of Mexico and Yucatan Peninsula transition, where climatic characteristics converge within a small geographic area. In order to conserve beach and coastal dune plant biodiversity, special attention must be paid to the management plans of established protected areas and to the promotion of new protected areas consistent with the areas reported in this study, particularly in the central Gulf of Mexico and northern Yucatan Peninsula, where areas under protection are currently scarce.

Classification of Beach Erosion Vulnerability on the Yucatan Coast

ABSTRACTBeach erosion can have important socioeconomic and environmental consequences, particularly in tropical regions where tourism is a significant source of income. Although caused by natural processes, erosion is often aggravated by disorderly anthropogenic modification of the coast and extreme events. In Yucatan, Mexico, increasing urban development and deficient coastal management strategies as well as hurricanes have affected beach stability. This has highlighted the need for adequate coastal planning and policies that ensure the protection of key coastal ecosystems, such as beaches and sand dunes. To address this, a methodology to classify the coast according to its vulnerability is presented in this work. This methodology assumes that morphological features are indicators of beach evolution and the processes driving it and that these can be associated with different levels of vulnerability. The features considered are beach width, dune vegetation, anthropogenic pressure, and shoreline orientation, which were analyzed through aerial images and a multicriteria evaluation. It was observed that the most vulnerable areas are found near the most developed parts of the coast, where narrow beaches with little dune vegetation dominate. It is expected that this index will be of use to coastal planners and decision makers, particularly in the identification of critical zones.

Effect of artificial seagrass on wave attenuation and wave run-up

Natural processes like wave action, tides, winds, storm surges, and tsunamis constantly shape the shoreline by inducing erosion and accretion. Coastlines with intact vegetated dunes, mangroves, and reefs act as a buffer zone against wave attack on beaches. This article discusses the effect of simulated seagrass on wave height attenuation and wave run-up through an experimental study. The tests were carried out with submerged artificial seagrass subjected to varying wave climate in a 50-m-long wave flume. Measurements of wave heights along the seagrass meadow and the wave run-up on a 1:12 sloped beach were taken for wave heights ranging from 0.08 to 0.16 m at an interval of 0.02 m and wave periods 1.8 and 2 seconds in water depths of 0.40 and 0.45 m.

Floristic survey of flowering plants in a tropical coastal ecosystem in Veracruz, Mexico

Mexico is a megadiverse country and Veracruz is one of the states with the highest floristic diversity. The reserve of La Mancha in central coastal Veracruz comprises several vegetation types. In this site we conducted for a year, monthly surveys of flowering or fruiting plants in six vegetation types, considering the frequency of occurrence of different species. We found a total of 147 species (131 genera and 63 families). The families most represented were Asteraceae, Fabaceae and Verbenaceae. In addition, we found nine species that had not been reported in previous floristic studies. The highest taxonomic richness was observed in the tropical deciduous flood forest with wetland (59 species), while the highest diversity was found in tropical deciduous forest (ISI = 0.9562). We also found that the most similar vegetation types based on the composition and frequency of species were, coastal dune scrub, tropical deciduous forest and pioneer dune vegetation. The dominant plant biological form in La Mancha were herbs (40.41 %) followed by shrubs (23.97 %), vines-lianas (18.49 %) and trees (17.12 %). This study is the first to consider the frequency-occurrence of flowering and fruiting plants in La Mancha, covering six vegetation types through one year. The more relevant results of this study show the diversity of plants in different environments using the frequency of each species based on reproductive events. This information could be useful in future researches that evaluate plant-animal interactions, like pollination and seed dispersal.

Environmental growth of the faecal indicator Enterococcus moraviensis

Soil passage through sand dunes has previously been shown to remove enteric micro-organisms very effectively, and hence is used for the production of drinking water. However, enterococci have occasionally been isolated from abstracted water (after dune passage) in one of the dune infiltration areas in the Netherlands. Enterococcus moraviensis was the most frequently isolated species. Until now, no faecal sources of this species have been reported and the potential for growth under certain environmental conditions was reported for other Enterococcus species. The aim of this study was to determine the ability of E. moraviensis to grow in habitats present in the dune passage process (dune vegetation, sediment from abstraction wells, biofilm developed using abstracted water and soil). Different concentrations of boiled and filtered (0.45 μm) plant extracts obtained from dune vegetation supported growth (up to 6 log), with maximum concentrations after 4 to 6 days at 15 °C. Although E. moraviensis was shown to be able to attach to the biofilm, no growth was observed in biofilm or in sediment and soil. These observations confound the use of E. moraviensis as a faecal indicator.

Long-term impacts of nitrogen deposition on coastal plant communities

Nitrogen deposition has been shown to have significant impacts on a range of vegetation types resulting in eutrophication and species compositional change. Data from a re-survey of 89 coastal sites in Scotland, UK, c. 34 years after the initial survey were examined to assess the degree of change in species composition that could be accounted for by nitrogen deposition. There was an overall increase in the Ellenberg Indicator Value for nitrogen (EIV-N) of 0.15 between the surveys, with a clear shift to species characteristic of more eutrophic situations. This was most evident for Acid grassland, Fixed dune, Heath, Slack and Tall grass mire communities and despite falls in EIV-N for Improved grass, Strand and Wet grassland. The increase in EIV-N was highly correlated to the cumulative deposition between the surveys, and for sites in south-east Scotland, eutrophication impacts appear severe. Unlike other studies, there appears to have been no decline in species richness associated with nitrogen deposition, though losses of species were observed on sites with the very highest levels of SOx deposition. It appears that dune vegetation (specifically Fixed dune) shows evidence of eutrophication above 4.1 kg N ha−1 yr−1, or 5.92 kg N ha−1 yr−1 if the lower 95% confidence interval is used. Coastal vegetation appears highly sensitive to nitrogen deposition, and it is suggested that major changes could have occurred prior to the first survey in 1976.

The effect of dune vegetation on leatherback hatchling’s sea-finding ability

Leatherback turtles, Dermochelys coriacea, are affected by a range of anthropogenic stressors throughout their range. However, little is known about the species’ responses to natural threats such as dune vegetation, which can have a negative effect on the quality of nesting habitats. In this study, we assessed the potential impact of Ipomoea pes-caprae on the sea-finding abilities of leatherback hatchlings at the Pacuare Nature Reserve on the Caribbean coast of Costa Rica. To analyse their effects on hatchling behaviour, we measured and compared the speed at which hatchlings managed to reach the water at open beach locations and vegetated locations. We recorded nest locations of 1491 nests, which were left in situ, and 784 that were relocated between 2012 and 2014. The majority of in situ nests were located in areas where the vegetation was denser than in open beach. We found that dune vegetation had a negative effect on hatchling speed, which led to an increased exposure time to predators and dehydration and could potentially entail extreme physiological stress affecting hatchling mortality. Thus, the presence of vegetation might negatively influence the suitability of nesting habitats if beach erosion processes increase on nesting grounds in the future.

「海浜植物群落の保全・復元に向けた取り組み－景観生態学からの展望」を特集するにあたって

「海浜植物群落の保全・復元に向けた取り組み－景観生態学からの展望」を特集するにあたって

The Mediterranean Ammophiletea Database: a comprehensive dataset of coastal dune vegetation

This paper introduces the Mediterranean Ammophiletea Database (GIVD ID: EU-00-016), reporting history of data collection, current content and further development of this new research infrastructure for coastal dune vegetation. The main aim was to compile, in a unique repository, vegetation plot data of psammophilous herbaceous communities (Ammophiletea and Helichryso-Crucianelletea maritimae phytosociological classes) from Southern Europe and Northern Africa. In 2016 the database contained 7,769 releves and 1,586 species from the Mediterranean basin, the South Atlantic side of Europe (Morocco, Portugal and Spain) and the Black Sea. A total of 200 bibliographic references were used to digitize phytosociological releves currently stored in Turboveg software. Most plots were georeferenced to a precision of < 1 km. 80% of the plots include information about plot size and 74% about total cover of the sampled communities. The database is registered in the Global Index of Vegetation Database (GIVD) and is available by request through the European Vegetation Archive (EVA).

Seasonal change monitoring and mapping of coastal vegetation types along Midnapur-Balasore Coast, Bay of Bengal using multi-temporal landsat data

The present study highlights the application of satellite remote sensing in seasonal change monitoring and mapping of coastal vegetation types along Midnapur-Balasore coast, Bay of Bengal, using multi-temporal satellite images of Landsat ETM+ of 2000, 2001 and 2002 of pre-monsoon and post-monsoon seasons. Two types of image analysis techniques were applied in this study to identify different species of coastal vegetations, health and their areal extent. RGB-NDVI was computed to detect and monitor the changes of vegetation health during pre and post-monsoon period. Another technique is supervised digital classification was used for mapping of different coastal vegetations and to determine their spatial extent of the study area. Five major coastal vegetation types were delineated using satellite data viz., dune vegetation, mangroves, salt marsh, agricultural lands and other vegetations. An attempt has been made to analyze seasonal change monitoring and mapping of different coastal vegetations communities including mangroves, salt marsh, and dune vegetation from 2000 to 2002 using Landsat 7 ETM+ data. From 2000 to 2002 it is observed that the areal extent of salt marsh and dune vegetation is changed seasonally along each littoral cell. It is increased during post-monsoon season and decrease during pre-monsoon season. In this period, the gain of 704.34 ha area of salt marsh and 2153.88 ha area of dune vegetations cover was noticed. During post-monsoon period the mangrove vegetation covers along all littoral cells have increased this may be due to supply of huge amount of sediment and increase of salinity condition after monsoon. But over the entire 3 years period from pre-monsoon 2000 to post-monsoon 2002 the net change was negative, which was quantified as 61.83 ha. The depletion of mangroves may be due to high anthropogenic pressure, commercial aquaculture, highly eroding nature of the coast and tidal activities. The NDVI derived from ETM+ images provide useful information to monitor coastal vegetation changes, especially the natural plants growing on sand dunes, mangroves and salt marsh vegetations. The analysis of NDVI variations showed the qualitative information about the vegetation. On the other hand classified image provide quantitative information about the coastal vegetation.

Quantifying energy and water fluxes in dry dune ecosystems of the Netherlands

Abstract. Coastal and inland dunes provide various ecosystem services that are related to groundwater, such as drinking water production and biodiversity. To manage groundwater in a sustainable manner, knowledge of actual evapotranspiration (ETa) for the various land covers in dunes is essential. Aiming at improving the parameterization of dune vegetation in hydrometeorological models, this study explores the magnitude of energy and water fluxes in an inland dune ecosystem in the Netherlands. Hydrometeorological measurements were used to parameterize the Penman–Monteith evapotranspiration model for four different surfaces: bare sand, moss, grass and heather. We found that the net longwave radiation (Rnl) was the largest energy flux for most surfaces during daytime. However, modeling this flux by a calibrated FAO-56 Rnl model for each surface and for hourly time steps was unsuccessful. Our Rnl model, with a novel submodel using solar elevation angle and air temperature to describe the diurnal pattern in radiative surface temperature, improved Rnl simulations considerably. Model simulations of evaporation from moss surfaces showed that the modulating effect of mosses on the water balance is species-dependent. We demonstrate that dense moss carpets (Campylopus introflexus) evaporate more (5 %, +14 mm) than bare sand (total of 258 mm in 2013), while more open-structured mosses (Hypnum cupressiforme) evaporate less (−30 %, −76 mm) than bare sand. Additionally, we found that a drought event in the summer of 2013 showed a pronounced delayed signal on lysimeter measurements of ETa for the grass and heather surfaces, respectively. Due to the desiccation of leaves after the drought event, and their feedback on the surface resistance, the potential evapotranspiration in the year 2013 dropped by 9 % (−37 mm) and 10 % (−61 mm) for the grass and heather surfaces, respectively, which subsequently led to lowered ETa of 8 % (−29 mm) and 7 % (−29 mm). These feedbacks are of importance for water resources, especially during a changing climate with an increasing number of drought days. Therefore, such feedbacks need to be integrated into a coupled plant physiological and hydrometeorological model to accurately simulate ETa. In addition, our study showed that groundwater recharge in dunes can be increased considerably by promoting moss vegetation, especially of open-structured moss species.

Assessment of Beach Access Paths on Dune Vegetation: Diversity, Abundance, and Cover

ABSTRACT Purvis, K.G.; Gramling, J.M., and Murren, C.J., 2015. Assessment of beach access paths on dune vegetation: Diversity, abundance, and cover. Coastal human populations are expanding and affecting plant communities, in particular dune systems. Coastal communities face risks from storm events, while coastal dune systems are heavily affected by human population and recreation pressures. Here, we evaluate the impacts of human disturbance (beach access paths) on vegetative cover and plant diversity in coastal dunes on the Isle of Palms, South Carolina. Transects were created in the foredune, middune, and backdune vegetation communities, and plots were placed 0, 1.5, 5, 10, and 20 m from a path to assess the impacts of three types of paths (public sand paths, private sand paths, and private wooden paths) at these distances on diversity, abundance, and measures of cover. Results indicate that beach access paths reduce biodiversity and density of beach dune vegetation. Sand paths contribute to greater redu...

Levantamento florístico de um remanescente de Mata Atlântica no litoral norte do Estado da Bahia, Brasil

RESUMO A Mata Atlântica do Nordeste brasileiro abriga diversas fisionomias, tendo cerca de 46% dos seus remanescentes localizados no Estado da Bahia. Entretanto, inventários florísticos realizados no Domínio Atlântico no Estado estão geralmente concentrados em áreas no litoral sul e de restinga no litoral norte. Dessa forma, o presente trabalho realizou o levantamento florístico de um remanescente de Floresta Estacional Semidecidual, na Fazenda Regional de Criação/UFBA, município de Entre Rios, litoral norte do Estado. Foram registradas 192 espécies, distribuídas em 139 gêneros e 59 famílias. A presença de duas espécies novas, uma espécie rara, quatro espécies com distribuição restrita para essa região e duas citadas como vulneráveis demonstram a importância dos remanescentes de Mata Atlântica do litoral norte da Bahia, visto que eles possuem riqueza e características fisionômicas não encontradas em outras áreas do Domínio Atlântico.

Human use and modification of beaches and dunes are linked to ghost crab (Ocypode spp) population decline in Ghana

The increasing urbanization of much of the world’s coasts threatens irreversible damages to beach ecosystems, if unchecked. Unfortunately, beach monitoring programmes for remediation actions are uncommon, especially for less developed nations where infrastructural development and socio-economic goals are regarded more important than environmental goals. This study aimed at obtaining information about the effects of the modification and use of beaches and dunes on beach biota using ghost crab burrow density and size as variables. The study tested a hypothesis that the mean densities and sizes of ghost crab burrows on six beaches under three categories of human use in the Central Region of Ghana are different. Results indicated that low use beaches had significantly higher numbers of burrows and larger burrow sizes compared to medium use and high use beaches. Since physical and environmental parameters were consistently the same amongst the six surveyed beaches, the paper concluded that the differences in the observed beach use and dune modifications were responsible for the observed differences in ghost crab abundance and sizes. Major beach use such as intense trampling levels and clearing of dune vegetation for infrastructural developments are most likely responsible for the observed differences. On account of ecological considerations, it is recommended that beach land use reforms by coastal municipal authorities in Ghana should ensure that infrastructure development along undeveloped sections of the coast is limited to a safe distance from the shoreline. There should also be consideration of natural vegetation barriers between development and the beach to enhance natural beach–dune ecosystem interaction.

Impact of invasive Rosa rugosa on the arthropod fauna of Danish yellow dunes

We compared the arthropod fauna of Rosa rugosa patches to the adjacent native yellow dune vegetation by pitfall trapping in the National Park Thy at the Danish North Sea coast. R. rugosa changes the vegetation from a dune grassland (dominated by Ammophila arenaria) poor in flowering plants to a low monospecific shrubbery rich in large flowers. We predicted faunal responses according to the changes in resource availability and environmental conditions promoted by this particular invasive plant: increased populations of flower-visiting insects and species of the phytophagous and detritivorous guilds, and a decrease in thermophilic predator species. A matched-pairs sampling design allowed us to isolate the effects of the vegetation change from those of potentially confounding landscape gradients. The arthropod communities were significantly affected by the vegetation change (redundancy analysis). Six taxa (Opiliones, Lepidoptera larvae, Hymenoptera, Diptera, Tipulidae, Geotrupidae) increased in abundance, and three (Araneae, Staphylinidae, Auchenorrhyncha) were reduced in the rose patches. The main exception from predictions was the lack of effects on large detritivores (isopods, diplopods). Overall, total catches were increased by 45 % in the rose patches, primarily caused by an increase in the abundance of Diptera. Arachnids and carabid beetles were analyzed at species level: the assemblage structure was significantly affected in arachnids but not in carabids. Arachnids showed reduced species richness and diversity and increased dominance in the rose patches, due to reductions among xerotherm species. The results indicate that considerable faunistic impoverishment of thermophilic dune specialist species can be expected in the future if R. rugosa is allowed to continue its invasion across the dune habitat.

Species composition of coastal dune vegetation in Scotland has proved resistant to climate change over a third of a century.

Climate change is expected to have an impact on plant communities as increased temperatures are expected to drive individual species' distributions polewards. The results of a revisitation study after c. 34years of 89 coastal sites in Scotland, UK, were examined to assess the degree of shifts in species composition that could be accounted for by climate change. There was little evidence for either species retreat northwards or for plots to become more dominated by species with a more southern distribution. At a few sites where significant change occurred, the changes were accounted for by the invasion, or in one instance the removal, of woody species. Also, the vegetation types that showed the most sensitivity to change were all early successional types and changes were primarily the result of succession rather than climate-driven changes. Dune vegetation appears resistant to climate change impacts on the vegetation, either as the vegetation is inherently resistant to change, management prevents increased dominance of more southerly species or because of dispersal limitation to geographically isolated sites.

Plant selection and grazing activity of the invasive snail Theba pisana in coastal Algoa Bay, South Africa

The land snail Theba pisana is a coastal species native to the Mediterranean but has been introduced to regions all over the world, including South Africa and Australia, where it is considered a pest. This study examines the diet of T. pisana and its preference for certain dune plants in the Cape Recife Nature Reserve of Algoa Bay in the Eastern Cape, South Africa. Field observations identified plants being fed on by T. pisana, accounting for almost half of the dune plant species present in the study area. Five plant species, on which snails were found frequently and in high abundance, were selected for feeding preference experiments. Laboratory experiments and field observations indicate that T. pisana feed preferentially on Tetragonia decumbens over Osteospermum moniliferum, Osyris compressa and Cynanchum obtusifolium. It is clear that while T. pisana is reported to have a generalist diet, consuming a range of plant species commonly found in South African dune vegetation, it also exhibits a definite preference for T. decumbens. The reasons for this preference need to be investigated further.