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The purpose of this study was to determine possible damage created by recreational activities in Yedigoller (Seven Lakes) National Park and to recommend recreational impact management decisions in order to ensure its sustainable use. Four picnic and camping areas and one control area in the National Park were selected as sampling areas. In order to determine the ecological effects of recreational activities and the pressures on the plant life and the soil, an observation form was used. The study also addressed the stress on the Fagus orientalis trees in all recreation areas near Nazli Lake, Buyuk Lake, and Derin Lake. Findings from the soil analysis indicated that in general, intense human activities in the area had negatively affected both the physical and chemical properties of the soil. As a result of the evaluation of the observation forms, all of the sampling areas in the park were determined to be in poor condition. project titled Research on Possible Damage of Recreational Activities in Yedigoller National Park This study was supported by the project titled Research on Possible Damage of Recreational Activities in Yedigoller National Park upon the request of the Nature Conservation and National Parks 9th Regional Directorate of the Bolu National Parks Branch Directorate. We also thank Assoc. Prof. Dr. Hulya Torun for contributing to the measurement of the physiological parameters in the study. WOS:000674564600002 2-s2.0-85110806711

This paper explores the relationship in three sedimentary systems of the Canary Islands (Spain) between four major land change processes (resource extraction, urbanization, tourism and nature protection) and six main environmental consequences (impacts on aeolian sedimentary dynamics, changes in sand landforms, disappearance of sand landforms and entire systems, changes in vegetation, impacts on the socioeconomic system, and changes in land use patterns). The results show that all the environmental consequences have impacted all three study sites, except in one of them (La Graciosa island) in producing disappearance of sand landforms and entire systems. It should be noted that the environmental consequences described concerns different scales (from entire systems to landforms). All the impacts are described and analyzed separately, and the results are discussed in detail and in relation to the presence of these environmental consequences in other parts of the world.

The aim of the present study is to present an actual information about the diversity and distribution of alien and native invasive plant species in the Sand Dunes and adjacent lakes of the Alepu Marsh and to assess the threat these species pose to the NATURA 2000 habitats in question. The study area is 178.7ha and includes the following habitat types according the Council Directive 92/43/EEC: 1150 Coastal lagoons, 2130 Fixed dunes with herbaceous vegetation (‘grey dunes’) and 2190 Humid dune slacks. The investigation was held in the period May-June, 2022. Sample plots were set up on each locality of the invasive species for the estimation of species abundance. The size of the sample plots was 10 m2 for grasslands and 100 m2 for woodlands and shrublands. Species abundance is measured by plant cover (%) in a sample plot. To assess the impact of each of the influences and threats from the invasive species, the three-level scale was used: H- High - currently acting and/or affecting a large area (>60%) of the habitat; M- medium- has been active in the past and has a high probability of recurrence and/or affects a small area (Acer negundo L., Ailanthus altissima (Mill.) Swingle, Amorpha fruticosa L., Broussonetia papyrifera (L.) L'Hér. ex Vent., Eleagnus angustifolia L. Erigeron canadensis L., Laburnum anagyroides Medik., Parthenocissus quinquefolia (L.) Planch., Robinia pseudoacacia L., Spartium junceum L., Xanthium italicum Moretti. Among the native plants the following species can be mentioned as invasive: Phragmites australis (Cav.) Trin. ex Steud. (this species is not noted in Table 1 because it is widespread in the study area), Paliurus spina-christi Mill., Tamarix ramosissima Ledeb. and Rubus discolor Weihe & Nees. The most dangerous to the habitats invasive alien species is False indigo (Amorpha fruticosa) and at the current stage the risk of this species impact is assessed as medium. Among the native species, Common reed (Phragmites australis) is the most aggressive species with high level of impact. The main routes for the spread of invasive alien pant species in the area are determined by the proximity of the hotel complex, where all the established invasive alien species are cultivated; the canal, which is the active water connection between the lakes and the dunes; the coastal road ruderalised in placed and the increased flow of tourists whose vehicles carry seeds and plant parts., {"references":["1.\tPalazov, A., R. Young, M. Stancheva, H. Stanchev. 2012. EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria., p.3039","2.\tProtected Areas Act.1998, Last amended 26.07.2013, State Gazette. (in Bulgarian)","3.\tBiological Diversity Act. 2002, Last amended 26.07.2016, State Gazette. (in Bulgarian)","4.\tAct on the Black sea coast spatial development. 2008, Last amended,State Gazette. (in Bulgarian)","5.\tGreen corridors. 2022. Alepu Marsh and Sand Dunes Alepu. https://greencorridors.burgas.bg/en/objects/view/16","6.\tCouncil Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. OJ L 206, 22.7.1992, p. 7–50","7.\tPavlov, D., M. Dimitrov. 2012. Phytocoenology. Publishing house University of forestry, 283pp. (in Bulgarian)","8.\tGusev, Ch., S. Bancheva. 2011. Methodology for monitoring of vascular plants. National Biodiversity Monitoring System. Executive Agency Environment. https://eea.government.bg/bg/bio/nsmbr/praktichesko-rakovodstvo-metodiki-za-monitoring-i-otsenka/visshi-rasteniya","9.\tPetrova A., V. Vladimirov, V. Georgiev. 2013, Invasive alien species of vascular plants in Bulgaria, IBER – BAS, Sofia, 320 pp.","10.\tPeev, D., Petrova, A.S., Anchev, M., Temniskova, D., Denchev, C.M., Ganeva, A., Gussev, Ch., Vladimirov, V. (Eds). 2015. Red Data Book of the Republic of Bulgaria. Vol. 1. Plants and Fungi. Publisher: Ministry of Environment and Waters. ISBN: 978-954-9746-21-1 http://e-ecodb.bas.bg/rdb/bg/","11.\tIvanova, I., N. Stankova, D. Borisova, T. Spasova, A. Dancheva. 2021. Dynamics and development of Alepu marsh for the period 2013-2020 based on satellite data. Proceedings Volume 11863, Earth Resources and Environmental Remote Sensing/GIS Applications XII; 1186315 https://doi.org/10.1117/12.2597726","12.\tTzonev, R. 2012. Black Sea fixed (gray) dunes. In: Bisserkov V. et al. (eds). Red Data Book of Bulgaria. Vol.3. Natural habitats. http://e-ecodb.bas.bg/rdb/en/vol3/"]}

The Remolar beach-dune system (700 m long and more than 100 m wide, 070N direction) borders a campground that was closed (2003), due to the Barcelona airport expansion. In order to recover and restore the dune ecosystem, a series of soft measures were performed. After 10 years, a study of the morphology, sedimentology, and vegetation of the ecosystem was carried out to evaluate the results of these measures. For this purpose, a series of topographic and ground-penetrating radar (GPR) profiles, grain-size analysis, and an analysis of plant communities found along the profiles were carried out. The data obtained were compared with data from a former 2004 study. The results show that the morphology of the dunes recovered, and a new primary dune has arisen. The system now has a greater process of aggradation than of progradation. The vegetation has recovered the global composition of dune systems, with a typical community of embryo dunes and others of primary dunes that are set in strips parallel to the coast. Despite this improvement, the opportunistic and ruderal component in the primary dune vegetation evidences a strong anthropic inheritance in the system.

The invasive ecosystem engineer Ammophila arenaria, native to Europe, was first introduced to California (USA) in 1896. More than a century later, it has come to dominate coastal foredune vegetation on the west coast of North America to the near exclusion of native species. A. arenaria builds a narrow, steep, peaked, and densely vegetated foredune, in contrast to the broad, more sparsely vegetated foredunes built by the native Elymus mollis. As such, it has modified dune processes by fixing the foredune and disrupting exchange of sediment between the beach, foredune, and dunefield. In the 1930s the congener A. breviligulata, native to the east coast and Great Lakes USA, was first introduced to Oregon, and has been displacing A. arenaria in southern Washington. Ammophila spp. have drastically reduced biodiversity, outcompeting native plant species, and displacing both invertebrate and vertebrate species. Restoration of west coast dunes through the removal of Ammophila began in the 1990s. Methods usually consist of one or a combination of manual digging, burning/herbicides, or excavation with heavy equipment. There are benefits and disadvantages to each method. Manual removal has proven most effective at restoring foredune form and process but is expensive. Excavation and herbicides may result in the loss of foredune morphology. Managers must articulate goals carefully before selecting restoration methods.

A common perception of plantation forests is that they constitute an “ecological desert” and that is why they are often disdained by scholars. Distribution patterns of understorey assemblages of coastal pine stands on sand dunes are still little known, despite such forests being widespread along the Mediterranean coastline, particularly in Italy. The purpose of this study of 167 plots along Italian coastlines was to analyse whether similar communities and specific species pools occur in different pine forest types dominated by Pinus pinea , P. halepensis or P. pinaster . Multivariate analysis was used, including the effects of sea-inland gradient and of pine canopy cover. The results indicated that pine forests show the lack of a clear floristic differentiation among different pine forest types at community level. Nevertheless, psammophilous species of coastal dunes occurring mostly in P. halepensis stands, and forest species mainly being linked to P. pinea stands, indicated a distinctiveness at species level probably related to different pine ecology as well as to the coastal zonation along the sea-inland gradient, already well-known for non-forested dunes. Thus, the natural zonation of coastal vegetation is maintained, although higher pine canopy cover affected the understory species assemblages, both herbaceous and woody, in a negative way. In light of this, species-specific management strategies are not recommended for Mediterranean coastal pine forests, and a long-sighted management should take into account actions considering floristic differentiation linked to coastal vegetation zonation. These findings should not be disregarded since they have implications for management planning and conservation and because understoreys of Mediterranean pine plantations, with a species reservoir of unknown value, have often hitherto been overlooked.

Coastal dunes provide the hinterland with natural protection from marine dynamics. The specialized plant species that constitute dune vegetation communities are descriptive of the dune evolution status, which in turn reveals the ongoing coastal dynamics. The aims of this paper were to demonstrate the applicability of a low-cost unmanned aerial system for the classification of dune vegetation, in order to determine the level of detail achievable for the identification of vegetation communities and define the best-performing classification method for the dune environment according to pixel-based and object-based approaches. These goals were pursued by studying the north-Adriatic coastal dunes of Casal Borsetti (Ravenna, Italy). Four classification algorithms were applied to three-band orthoimages (red, green, and near-infrared). All classification maps were validated through ground truthing, and comparisons were performed for the three statistical methods, based on the k coefficient and on correctly and incorrectly classified pixel proportions of two maps. All classifications recognized the five vegetation classes considered, and high spatial resolution maps were produced (0.15 m). For both pixel-based and object-based methods, the support vector machine algorithm demonstrated a better accuracy for class recognition. The comparison revealed that an object approach is the better technique, although the required level of detail determines the final decision.

The Coronavirus disease 2019 (COVID-19) is a pandemic that has altered practically all human activities worldwide. Since the pandemic started at the beginning of 2020, infections have fluctuated drastically over time. It is difficult to predict how this situation will evolve in the coming months/years or when a return to some semblance of ’normal’ activity might occur. Because of global lock-up and distancing measures, the beaches, otherwise filled with tourists, first emptied and then had a reduced density of visitors owing to a wide variety of social-distancing measures. Therefore, new safety protocols need to include a wide range of aspects, such as epidemiological conditions, socioeconomic realities, and ecological contexts in which the pandemic occurs. Here, we propose new nature-based landscapes for sandy beaches to help maintain the social distancing of beach visitors while beaches and dunes are restored. When sufficient sediment is available, the maintenance and restoration of healthy beaches with incipient dunes and vegetation will help reduce contagion, promote human health, and recover natural ecosystems.

Different successional stages, aged up to 205 years since the first tree individuals established, were identified and vegetation studied using 1200 permanent plots established in 1988 in three adjacent drift sand dune complexes of different successional age, and resampled during the past three decades in the Veluwe, central Netherlands. After two centuries, forest succession has proceeded to a pine forest with gradually increasing participation of native deciduous trees. However, their expansion has been arrested by browsing of wild ungulates. Species diversity peaked after about 40 years of forest succession, then declined, and increased again after 100 years. During the past three decades, the herb layer has differentiated in the oldest plots, and the spontaneous forest succession is still in progress. Besides open drift sand with early successional stages, also the spontaneously established late successional forests are valuable from the conservation point of view. Here we have stored a complete data set consisted of 10x10 m subplots of three (A, B and C) 200 x 200 m plots. Plots A and B were resampled only in 2003, while plot C also in 2018. Phytosociological relevés with records of vascular plants are provided in form of matrix in JUICE programme (Tichý 2002) including header data. These data from selected series of plots/years wera used for ordination analyses and to compare species composition of plot/years in a synoptic table.&nbsp

Coastal dunes occur along the sandy shores of most continents where they serve as coastal defence against flooding, provide areas for recreation, store drinking water and harbour unique biodiversity. Coastal dunes and the services they provide are threatened by climate-induced sea-level rise. This threat may be mitigated by the spontaneous formation of new dunes, for example in combination with mega-nourishments aimed at increasing beach width. Coastal dunes form by the interaction between vegetation, wind and wave action. Persistent dune development begins with the establishment of vegetation on the beach: the vegetation traps the wind-blown sand, forming an embryo dune. Over time an embryo dune can develop into a bigger foredune, increasing coastal safety. The formation and development of embryo dunes into foredunes depend on the vegetation establishment on the beach, dune growth over summer and dune erosion during winter. Although vegetation succession and geomorphological processes are each well described, the interaction between ecological and geomorphological processes during embryo dune development are not well known. The thesis aimed at further exploring these interactions, using a combination of experiments and high-resolution dune monitoring to study the mechanisms underlying early dune development and their implications for mega-nourishment design. To explore whether soil salinity, salt spray or storms determine the vegetation limit of dune building plant species on the beach, we performed a field transplantation experiment and a glasshouse experiment with two dune building grasses Ammophila arenaria and Elytrigia juncea. In the field growth of grasses transplanted into four vegetation zones from sea to dune was monitored for over a year and the response of these species to salt spray and soil salinity was tested in a glasshouse experiment. In the field, the vegetation zones were associated with differences in summer soil salinity: zones with both species present were significantly less saline than zones with only E. juncea or the zones without any vegetation. However, in our experiments the transplanted A. arenaria performed equal or better than E. juncea in all vegetation zones, suggesting soil salinity did not limit species performance at the studied site. Both species showed severe winter mortality. In the glasshouse experiment, A. arenaria biomass decreased linearly with soil salinity, presumably as a result of osmotic stress. Elytrigia juncea showed a nonlinear response to soil salinity with an optimum at 0.75% soil salinity and a decrease in biomass at higher salt concentrations. Our findings suggest that soil salinity stress either takes place in winter during storm inundation, or that development of vegetated dunes is less sensitive to soil salinity than hitherto expected. To understand the boundary conditions for embryo dune development over a longer time period we explored the effects of beach morphology, meteorological conditions and sand nourishment on early dune development using a 30 year time series of aerial photographs and beach profile monitoring data. We concluded that 1) beach morphology is highly influential in determining the potential for new dune development, with wide beaches enabling development of larger embryo dune fields, 2) sand nourishments stimulate early dune development by increasing beach width, and 3) weather conditions and non-interrupted sequences of years without high-intensity storms determine whether progressive dune development will take place. Dune development is the result of the interaction between vegetation development and sedimentation and erosion processes. To disentangle the effects of vegetation characteristics and that of dune size we monitored a natural dune field of 8 hectares for one year using an Unmanned Aerial Vehicle (UAV) with a camera. By constructing a digital surface model and a geometrical corrected image (an orthomosaic) for each flight campaign we calculated changes in dune volume over summer and winter and related these changes to vegetation, dune size and degree of shelter. The dune growth over summer was mainly determined by dune size, whereas dune growth over winter was determined by vegetation characteristics. Degree of shelter determined whether dune growth was limited by storm erosion (exposed dunes) or sand supply (sheltered dunes). These results suggest that vegetation characteristic may be particularly important for resisting storm erosion and speeding up recovery after erosion. Embryo dunes have been hypothesised to facilitate development of species rich green beach vegetation in the sheltered location between the embryo dunes and the primary foredunes. To test this hypothesis we explored the relative impacts of abiotic soil conditions as affected by the geomorphological setting on the species richness and species turn-over of green beach vegetation. To this end we characterised the geomorphology and measured abiotic conditions and species composition of green beach vegetation along transects from beach to foredune. We found that the geomorphological setting influenced plant species composition indirectly by affecting soil salinity and rate of sand burial. We found that plant species richness declined less at sheltered conditions, where there was a build-up of organic matter and no sand burial. Our results further suggest a non-linear relationship between embryo dune volume and number of green beach species: embryo dunes can be a source of shelter, thus stimulating green beach development, but can also compete for space, reducing green beach development. The net effect of embryo dunes most likely depends on the sediment budget of the beach and storm intensity. Mega-nourishments are single large sand nourishments that are applied locally, and are expected to exist for about 20 years, providing opportunities for the development of embryo dunes and rare pioneer plant communities (green beach vegetation). We explored this potential by comparing growth and development of dune building species on natural beaches with the results of plant transplantation and monitoring data of two mega-nourishments: the low-elevated Hondsbossche Duinen and the high-elevated Sandmotor. Our results suggest that establishment of dune building species on high-elevated mega-nourishment proceed slower than on natural beaches due to dispersal limitation. Once vegetation has established however, embryo dune development on high-elevated mega-nourishments may proceed faster than natural beaches due to low salinity and protection against storm erosion. Development of dune-building vegetation on the low-elevated mega-nourishment Hondsbossche Duinen showed the same rate and pattern as that on a natural beach. The potential for embryo dune development on mega-nourishments is far bigger than the potential for green beach development, since green beach vegetation develops under a narrower range of abiotic conditions. Such abiotic conditions can develop behind the shelter of embryo dunes or foredunes at low beach elevations. In conclusion this thesis shows that, 1) the potential of embryo dune development depends on a large beach width and low storm erosion which determines the vegetation limit. 2) Embryo dune growth over summer is mainly determined by existing dune volume and sand supply. 3) Heavy storms limit embryo dune development during winter, although dune erosion can be mitigated by vegetation composition. 4) On accreting beaches which continuously provide area for the development of new embryo dunes green beach vegetation can develop. 5) The design of a mega-nourishment determines the potential for the development of embryo dunes and green beach vegetation. Our findings provide insights in the interaction between ecological and geomorphological processes that determine embryo dune development. This knowledge can help to obtain better predictions of embryo dune development under the threat of sea-level rise.

Herein, a phenomenological theory that unifies the flow resistance caused by a variety of submerged bluff bodies, including cylindrical vegetation, two-dimensional dunes and the roughness elements studied in Schlichting's 1936 experiments, is presented. For the different flow obstructions, scaling relations that relate the equivalent roughness length to the obstructions’ spatial dimensions are derived, by adopting the concepts of the turbulent energy cascade and the momentum thickness in the wake of a bluff body. In the derivation, it is hypothesized that the equivalent roughness height represents the volumetric average of the prevailing turbulence length scale that is present in wakes of the roughness elements. A comparison with experimental literature data indicates that the derived scaling relations capture the dominant dependencies of the equivalent roughness length. These expressions have important engineering applications in large-scale flows where employment of more detailed flow-modelling techniques is not feasible.

[EN] A botanical survey has been conducted to determine the influence of invasive species on the main indigenous communities in the Spanish Mediterranean coast and evaluate the current status of these communities in the eastern coast of Spain. The work was done in about 35 km of coastline located in Valencia (Spain). A total of 361 species cataloged are present in the study area, belonging to 79 different families. 49 of them have been inventoried invasive species which currently affect 38 plant communities. For this cause, we have developed a map of location finding out the area occupied by the same at every point and key to indigenous communities it affects. The plant communities characteristic of semi-mobile dunes Centaureo maritimae-Echietum sabulicolae and Medicagini marinae-Ammophiletum australis have turned out to have a greater degree of invasion. Carpobrotus edulis, Agave americana, Arundo donax, Oxalis pes-caprae and Cortaderia sellowiana are invasive species that cause further encroachment, both in area as a number of vegetation communities they affect., This study is part of a project to study the coast by the UPV and directed by Jose Serra, has been sponsored by government institutions (General Directorate of Coasts, Ministry of Environment (“Ministerio de Medio Ambiente y Medio Rural y Marino”) and Wildlife Service of Valencia Regional Government (Generalitat Valenciana, the Local Government of the Valencian region).

The root-feeding nematode community of wild plants may vary throughout their natural range. Little is known about how the variation of wild plants along their range affects their relationship with root-feeding nematodes. In the present study, we examined local and non-local combinations of host plants and root-feeding nematodes to test the hypothesis that nematode reproduction is favoured by local hosts. In two indoor experiments, we exposed populations of the wild dune grass Ammophila arenaria from northern and southern European coastal sand dunes to plant parasitic nematode species (Helicotylenchus spp.) from those same geographical origins. First, we used the southern nematode species to determine whether the effect of a local versus a non-local host may depend on nematode density. Then, in a cross-inoculation experiment we investigated how both nematode species performed with their local, as compared to the non-local hosts. In both experiments, plant biomass and ontogenetic characteristics were not significantly different between the northern and southern populations. The applied nematode densities did not have a negative impact on plant performance. This allowed us to consider the response of the two different nematode species and their host plants without co-varying differences in plant responses. Reproduction of the nematode species differed according to host origin, but contrary to what we expected, nematode species did not perform better on their local hosts. Helicotylenchus n. sp., the southern species originating from Portugal, performed better on the non-local than on the local host. Male to female ratios were significantly different between the two nematode populations and were lowest in Helicotylenchus pseudorobustus from The Netherlands. Female and juveniles percentages were also quite distinct, with more females in the nematode species from The Netherlands and more juveniles in the nematode species from Portugal. We concluded that ectoparasitic root-feeding nematodes Helicotylenchus spp. do not necessarily perform best on their local host population of the foredune grass A. arenaria. Our results imply that the natural distribution of Helicotylenchus spp. along the European coast is determined by other factors than host populations. These other factors that could be abiotic, e.g. water availability, or biotic, e.g. local natural enemies adapted to Helicotylenchus spp. Introducing plant genotypes from other parts of the natural range will, therefore, not necessarily lead to reduced abundance of semi-endo or ectoparasitic root-feeding nematodes.

Present state of vegetation of sand dunes in Vendée. Vastes areas of sand dunes line the coast of Vendée. Historical background to their knowledge is given, then the main features of the flora is sketched and a few problems are evoked. Then, the main plant communities and several variations are described. Despite numerous degradations, the richness of vegetation remains substantial and conservation management is imperative., D'importantes étendues de dunes longent le littoral de la Vendée. Après un historique de leur connaissance, les grands traits de la flore sont exposés et quelques problèmes sont évoqués. Puis les principaux groupements végétaux et diverses variations sont décrits. Malgré de nombreuses dégradations, la richesse de la végétation reste élevée et une gestion conservatoire s'impose., Dupont Pierre. L'état actuel du peuplement végétal des dunes de Vendée. In: Le Journal de botanique, n°32, 2005. pp. 5-31.

Coastal dunes are prominent features along many of the world’s sandy shorelines. They are valued for their contributions to flood protection, biodiversity, fresh water supply and recreation. The most seaward dune ridge or foredune is the most dynamic part, showing fluctuations in size and morphology in response to erosion by the sea and subsequent recovery by interactions between wind-blown sand and vegetation. Given their dependency on multiple natural processes, coastal dunes may be particularly sensitive to the effects of climate change, including sea-level rise (SLR) and changes in temperature and precipitation. To mitigate anticipated coastal erosion in the next decades, the Dutch sand nourishment regime will be intensified to raise the beach profile proportionally to the SLR. However, it is not clear how the added sand is distributed within the foredune system and whether this enables foredunes to keep up with sea-level rise. In addition, possibilities for dune re-mobilisation are investigated to enhance landward transport and biodiversity. However, effects of this intervention on foredune dynamics and the dune landscape are not entirely clear. This thesis has examined yearly to decadal scale foredune dynamics and the impacts of climate change and management options on these dynamics. Which factors control year-to-year variations in dune growth on the Dutch coast? Dunes depend on aeolian transport for sand supply. While measurements of aeolian transport show complex spatio-temporal variations, we find that the yearly sand supply to dunes along the Dutch coast is relatively constant, between 10-20 m3/m irrespective of the beach width (Chapter 2). This means that a wider beach does not necessarily provide more sand to dunes and beach width is not a limiting factor in sand supply to the dunes. In contrast to the sand input, the amount of sand lost during a storm surge does depend on the beach width. Wider beaches are able to dissipate more of the incoming wave energy and thus protect the dune better than narrow beaches. On a term of decades, this gives rise to steady dune growth on wider beaches and irregular, frequently interrupted growth on narrow ones. How do biogeomorphic interactions control foredune shape? The distribution of sand over the foredune, and therefore the morphological evolution, is strongly tied to vegetation patterns (Chapter 3). It was found that deposition patterns across foredunes show a characteristic distribution, starting with a sharp increase upon crossing the seaward vegetation limit, reaching a maximum between 5-20 m further landward and then gradually decreasing inland of the crest. The deposition pattern is further modified by the general vegetation pattern. On a timescale of years, there is no correlation between density of vegetation cover and the amount of accretion. However, by accounting for the gradual depletion of the sand load over the foredune, an empirical relationship can be defined between vegetation cover and its sand trapping efficiency. For fully covered surfaces, sand trapping efficiency is around 50%, indicating that sediment can pass densely covered foredunes. Although literature suggests a relation between the level of plant burial and plant growth, we found no evidence for enhanced vegetation growth in high-deposition zones. A gain in vegetation cover was found to occur for burial between 0 m/year and 1 m/year, which indicates that lower and upper tolerance limits of burial have not been exceeded. Other growth limiting factors are likely to be of similar importance, masking any possible dependency of vegetation growth on sand accretion. What are the effects of climate change on meso-scale evolution of coastal dunes? The results on yearly erosion/accretion and sedimentation patterns were implemented in a computer for dune evolution called DUBEVEG, developed in Wageningen (Chapter 4). Algorithms for aeolian transport and vegetation growth were taken from existing models and combined with a new module for wave action and dune erosion. The model was calibrated and validated against field measurements. The good agreement between observations and predictions indicates that the model successfully incorporates the suite of biogeomorphic and marine processes involved in dune building. Model simulations show that the evolution of a dune strongly depends on the sequence of storms and quiet periods. During quiet periods, dunes are able to build seaward at several metres per year as vegetation colonises the area near the dune foot, leading to dune accretion. Following the dune-foot position through time, we find an irregular pattern of seaward advance and regression. However, the average of a large number of runs with varying storm sequences reveals a clear trend. For a given wave climate and beach profile, we find that the model predicts a certain seaward limit to which the foredunes may build, or equilibrium position at which erosion and accretion are balanced. If the momentary position of the dune foot is seaward of this limit, seaward movement can be rapid. If, in contrast, the momentary position is at or seaward of the limit, periods of minor seaward growth are followed by periods of landward retreat, resulting in an oscillation around the equilibrium. Climate scenarios, consisting of SLR and a gradual change in vegetation growth, were developed to examine climate-change effects on dune dynamics. Sea-level rise largely determines the direction of dune evolution by forcing the dune-foot landwards. The rate of rising controls whether dunes are able to preserve their height or sand volume while migrating landwards. The effect of changing vegetation growth rates, resulting from climate change, is most manifest in dune response to large disturbances. If vegetation is removed halfway into the simulation, vegetation growth rate determines whether a foredune will re-vegetate and re-stabilise: a value below the threshold will preclude complete recovery and the dune remains bare. What management options are available to mitigate climate-change effects on coastal dune evolution? Sand nourishments are effective to mitigate the effect of SLR on coastal dunes. Model results show that by raising the beach proportionally to SLR, dunes are able to preserve their dunefoot position, height and volume. sHowever, the associated landward retreat is often not feasible. A reduction in vegetation cover, related to either (1) artificial remobilisation, (2) dunefoot erosion or (3) climate change promotes landwards transport and therefore contributes to the long-term preservation of a wider dune zone. If vegetation growth is reduced as a consequence of increasing summer drought, re-mobilisation becomes more effective, with high rates of landwards transport persisting for several decades. On the long term, it is recommended to use a combination of sand nourishments and remobilisation efforts to preserve the coastline, promote landwards transport and make benefit of a dune’s natural self-regenerating capacity. Under the precondition that safety requirements are met, these natural processes enable long-term preservation of flood protection, biodiversity and dynamic landscapes.

Coastal dunes are prominent features along many of the world’s sandy shorelines. They are valued for their contributions to flood protection, biodiversity, fresh water supply and recreation. The most seaward dune ridge or foredune is the most dynamic part, showing fluctuations in size and morphology in response to erosion by the sea and subsequent recovery by interactions between wind-blown sand and vegetation. Given their dependency on multiple natural processes, coastal dunes may be particularly sensitive to the effects of climate change, including sea-level rise (SLR) and changes in temperature and precipitation. To mitigate anticipated coastal erosion in the next decades, the Dutch sand nourishment regime will be intensified to raise the beach profile proportionally to the SLR. However, it is not clear how the added sand is distributed within the foredune system and whether this enables foredunes to keep up with sea-level rise. In addition, possibilities for dune re-mobilisation are investigated to enhance landward transport and biodiversity. However, effects of this intervention on foredune dynamics and the dune landscape are not entirely clear. This thesis has examined yearly to decadal scale foredune dynamics and the impacts of climate change and management options on these dynamics. Which factors control year-to-year variations in dune growth on the Dutch coast? Dunes depend on aeolian transport for sand supply. While measurements of aeolian transport show complex spatio-temporal variations, we find that the yearly sand supply to dunes along the Dutch coast is relatively constant, between 10-20 m3/m irrespective of the beach width (Chapter 2). This means that a wider beach does not necessarily provide more sand to dunes and beach width is not a limiting factor in sand supply to the dunes. In contrast to the sand input, the amount of sand lost during a storm surge does depend on the beach width. Wider beaches are able to dissipate more of the incoming wave energy and thus protect the dune better than narrow beaches. On a term of decades, this gives rise to steady dune growth on wider beaches and irregular, frequently interrupted growth on narrow ones. How do biogeomorphic interactions control foredune shape? The distribution of sand over the foredune, and therefore the morphological evolution, is strongly tied to vegetation patterns (Chapter 3). It was found that deposition patterns across foredunes show a characteristic distribution, starting with a sharp increase upon crossing the seaward vegetation limit, reaching a maximum between 5-20 m further landward and then gradually decreasing inland of the crest. The deposition pattern is further modified by the general vegetation pattern. On a timescale of years, there is no correlation between density of vegetation cover and the amount of accretion. However, by accounting for the gradual depletion of the sand load over the foredune, an empirical relationship can be defined between vegetation cover and its sand trapping efficiency. For fully covered surfaces, sand trapping efficiency is around 50%, indicating that sediment can pass densely covered foredunes. Although literature suggests a relation between the level of plant burial and plant growth, we found no evidence for enhanced vegetation growth in high-deposition zones. A gain in vegetation cover was found to occur for burial between 0 m/year and 1 m/year, which indicates that lower and upper tolerance limits of burial have not been exceeded. Other growth limiting factors are likely to be of similar importance, masking any possible dependency of vegetation growth on sand accretion. What are the effects of climate change on meso-scale evolution of coastal dunes? The results on yearly erosion/accretion and sedimentation patterns were implemented in a computer for dune evolution called DUBEVEG, developed in Wageningen (Chapter 4). Algorithms for aeolian transport and vegetation growth were taken from existing models and combined with a new module for wave action and dune erosion. The model was calibrated and validated against field measurements. The good agreement between observations and predictions indicates that the model successfully incorporates the suite of biogeomorphic and marine processes involved in dune building. Model simulations show that the evolution of a dune strongly depends on the sequence of storms and quiet periods. During quiet periods, dunes are able to build seaward at several metres per year as vegetation colonises the area near the dune foot, leading to dune accretion. Following the dune-foot position through time, we find an irregular pattern of seaward advance and regression. However, the average of a large number of runs with varying storm sequences reveals a clear trend. For a given wave climate and beach profile, we find that the model predicts a certain seaward limit to which the foredunes may build, or equilibrium position at which erosion and accretion are balanced. If the momentary position of the dune foot is seaward of this limit, seaward movement can be rapid. If, in contrast, the momentary position is at or seaward of the limit, periods of minor seaward growth are followed by periods of landward retreat, resulting in an oscillation around the equilibrium. Climate scenarios, consisting of SLR and a gradual change in vegetation growth, were developed to examine climate-change effects on dune dynamics. Sea-level rise largely determines the direction of dune evolution by forcing the dune-foot landwards. The rate of rising controls whether dunes are able to preserve their height or sand volume while migrating landwards. The effect of changing vegetation growth rates, resulting from climate change, is most manifest in dune response to large disturbances. If vegetation is removed halfway into the simulation, vegetation growth rate determines whether a foredune will re-vegetate and re-stabilise: a value below the threshold will preclude complete recovery and the dune remains bare. What management options are available to mitigate climate-change effects on coastal dune evolution? Sand nourishments are effective to mitigate the effect of SLR on coastal dunes. Model results show that by raising the beach proportionally to SLR, dunes are able to preserve their dunefoot position, height and volume. sHowever, the associated landward retreat is often not feasible. A reduction in vegetation cover, related to either (1) artificial remobilisation, (2) dunefoot erosion or (3) climate change promotes landwards transport and therefore contributes to the long-term preservation of a wider dune zone. If vegetation growth is reduced as a consequence of increasing summer drought, re-mobilisation becomes more effective, with high rates of landwards transport persisting for several decades. On the long term, it is recommended to use a combination of sand nourishments and remobilisation efforts to preserve the coastline, promote landwards transport and make benefit of a dune’s natural self-regenerating capacity. Under the precondition that safety requirements are met, these natural processes enable long-term preservation of flood protection, biodiversity and dynamic landscapes.

Een verzameling essays over de grote verscheidenheid aan natuur in Europa: wildernis, natuurlijke en oude cultuurlandschappen. Hoe staat het met de bescherming van deze uiteenlopende natuurtypen? Van de Europese laaglandrivieren en hun begeleidende hooilanden tot kalkmoerassen in de bergen: tal van bijzondere landschappen en hun verhalen komen aan bod. flora, fauna, biodiversiteit, natuurbeheer, halfnatuurlijke graslanden, plantengemeenschappen, vegetatiekunde, ecologie, duinen, kalkmoerassen, wateren, bevloeiingssystemen, wildernis, natuur in Europa

Coastal dunes are increasingly at risk due to pressures deriving from global climate change, sea level rise, recreation and development. The consequences of the “coastal squeeze” in which dunes are placed, such as erosion and the loss of critical ecosystem services, are usually followed by expensive restoration and protection measures, many of which are unsuccessful. Due to the poor understanding and acknowledgement of the key attributes of coastal dunes in decision making processes, it is essential to provide scientific data on the impacts of human interference on coastal dunes so as to inform executives and guide them towards a sustainable management of the coastal zone. The aim of this study was to investigate the impact of five different levels of infrastructure development on the vegetation community structure of coastal dunes in Jeffreys Bay, South Africa. The effects of infrastructure development on dune vegetation were quantified by measuring the richness, diversity, cover, height and composition of plant species. With an increase in infrastructure development a significant decrease in dune width, average species richness and height of the plants occurred, accompanied by a shift in plant community composition. The foredunes that were backed immediately by infrastructure presented significantly greater species richness, diversity, cover and height compared with the foredunes abutted by primary dunes. This study demonstrated that coastal dunes are environments which are sensitive to varying levels of human impact. Informed and comprehensive management planning of these environments is therefore imperative for the restoration and maintenance of remnant dunes and for the conservation of undeveloped coastal dunes.

Een verzameling essays over de grote verscheidenheid aan natuur in Europa: wildernis, natuurlijke en oude cultuurlandschappen. Hoe staat het met de bescherming van deze uiteenlopende natuurtypen? Van de Europese laaglandrivieren en hun begeleidende hooilanden tot kalkmoerassen in de bergen: tal van bijzondere landschappen en hun verhalen komen aan bod. flora, fauna, biodiversiteit, natuurbeheer, halfnatuurlijke graslanden, plantengemeenschappen, vegetatiekunde, ecologie, duinen, kalkmoerassen, wateren, bevloeiingssystemen, wildernis, natuur in Europa

Coastal dune fields and dune-body associated lakes were studied through sedimentological, malacological and palynological analyses. Lake deposits and palaeosoil horizons gave new information about phases of aeolian activity and dune building, coastline and sea level, vegetation history and cultural impact. After a period of intense aeolian activity (Late Pleistocene) that limited soil-forming processes, a wet aeolian field, recorded by podzolized sands and interdune wetland deposits, was present in the region. Around 5000 to 4000 yr BP sea level reached the current level and the coastline was situated c. 1 km further inland compared with the present situation. Subsequently lagoon-barrier island systems developed c. 4000 yr BP. Vegetation in the region during this time was a pine/oak forest. Between 4000 and 1600 yr BP the forest was replaced by a semi-natural heathland. Later the heathland was degraded, allowing dune migration and finally formation of a desert-like landscape. This process was probably a consequence of a combination of deteriorating climate during the ‘Little Ice Age’ (LIA) and overgrazing. To counteract sand invasion, reforestation efforts were initiated in the region c. 300 years ago and locally along the coastal margin between 1924 and 1940. Formation of the row of freshwater lakes bordering the dune field at present was contemporaneous with the initial reforestation phase. A close relation between lake formation and accumulation of sand dunes was found. Various types of dunes were identified, truncated dunes, parabolic dunes and transverse/oblique dunes. Dune migration caused an eastward displacement of lakes.

Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation. Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush.

Wie door de duinen van Goeree wandelt, ziet grotendeels de duindoorn overwoekerd landschap. Diezelfde duinen bestonden voor 1970 vrijwel uitsluitend uit lage, soortenrijke duingraslanden, zoals nu nog in Westduinen, een terrein van Zuid Hollands Landschap, te zien is. Ook het landschap achter de zeereep zag er anders uit. Landschap en landgebruik hangen nauw samen. Professor Karlè Sýkora sprak met Henk Mastenbroek, hovenier te Ouddorp, die zich nog veel belangrijke details van het boerenleven op Goeree voor 1970 herinnert. Een samenleving waar hij met weemoed op terugkijkt

Wie door de duinen van Goeree wandelt, ziet grotendeels de duindoorn overwoekerd landschap. Diezelfde duinen bestonden voor 1970 vrijwel uitsluitend uit lage, soortenrijke duingraslanden, zoals nu nog in Westduinen, een terrein van Zuid Hollands Landschap, te zien is. Ook het landschap achter de zeereep zag er anders uit. Landschap en landgebruik hangen nauw samen. Professor Karlè Sýkora sprak met Henk Mastenbroek, hovenier te Ouddorp, die zich nog veel belangrijke details van het boerenleven op Goeree voor 1970 herinnert. Een samenleving waar hij met weemoed op terugkijkt

The abundance and species richness of the germinable seed content of dung of free ranging horses was quantified and related to seven variables: plant species abundance in the field (cover) and in the horse diet, seed sizes (length, width and mass), seed longevity index and seed shape which was expressed as variance in seed dimensions. Analyses were run both across species, with species treated as independent data points, and for 40 ‘phylogenetically independent contrasts’. From 56 dung samples, 2.5 l each, 53,493 seedlings emerged, representing 106 different plant species, i.e. 21.4% of all species recorded in the established vegetation of the study sites. A majority of plant species (50%) was only found in less than 10% of the dung samples while 68% of the germinating species emerged with on average less than 1 seedling per dung sample. Overall dung seed density ranged on average between 280.4 and 525.2 seedlings per litre. Mean species richness of dung samples varied between 19 and 34 plant species. Urtica dioica , Veronica spp. and several graminoid species were among the most abundant and frequently out of dung emerging plant taxa. Dung seed content was positively correlated with plant species abundance in the field and in the diet. Relative dung seed density (i.e. per unit cover) was positively correlated with seed longevity index and negatively correlated with all three seed size variables. There was no significant relationship with seed shape. These relationships were not affected by phylogenetic constraints. As far as the possible role of endozoochory for conservation of plant diversity in grassland is concerned, the results emphasise the importance of large herbivores as potentially strong seed dispersal vectors.

Research was conducted in the nature reserve De Westhoek (De Panne, Belgium) in order to determine leaf-area-index (LAI) in different dune vegetation types by both direct (destructively) and indirect optical measurements. The destructive LAI determination was conducted in herbaceous and shrub vegetation types. It was found that the LAI of herbaceous vegetation ranges between 0.87 and 4.60 and the LAI of shrub vegetation between 2.25 and 3.58. Ground-based optical determination of LAI was only conducted in the shrub vegetation, by means of the SunScan (Delta-T Devices Ltd, Cambridge, UK). This indirect LAI method systematically overestimated direct LAI. Another applied optical method is the hemispherical photography (Nikon Coolpix 5000 camera). Airborne remote sensing data are used to establish a relationship between direct LAI and some vegetation indices. Based on the above established relationship a map of the horizontal LAI distribution in the nature reserve De Westhoek will be produced.

In een duinvalleigebied op Vlieland is begrazing ingevoerd. Welke effecten heeft dit op de vegetatie en fauna van het betreffende gebied?

Door de toenemende groei in de internationale luchtvaartsector, ziet Schiphol zich genoodzaakt om uit te breiden. Gezien de ruimteclaims en de milieuwetgeving zal voor de lange termijn een verdere uitbreiding van Schiphol op de huidige locatie moeilijker worden. Een alternatief voor de locatie Schiphol is het aanleggen van een eiland in de Noordzee. Dit rapport beschrijft en waar mogelijk kwanitificeert de effecten van de aanleg van een luchthaveneiland in de Noordzee op de ecologie van strand en duin. De belangrijkste effecten van een eiland in de Noordzee op strand en duin, zijn gelegen in veranderingen in kustmorfologie en saltspray. Veranderingen in de morfologie hebben het grootste effect op het strand (en zeereep) en veranderingen in saltspray op de vegetatie in de duinen. Voor strand en zeereep geeft een aanwaskust in de luwte van het eiland mogelijkheden voor natuurontwikkeling, maar voor de duinen betekent de afname van saltspray een achteruitgang in natuurbehoudswaarde van deze internationaal beschermde gebieden.

Door de toenemende groei in de internationale luchtvaartsector, ziet Schiphol zich genoodzaakt om uit te breiden. Gezien de ruimteclaims en de milieuwetgeving zal voor de lange termijn een verdere uitbreiding van Schiphol op de huidige locatie moeilijker worden. Een alternatief voor de locatie Schiphol is het aanleggen van een eiland in de Noordzee. Dit rapport beschrijft en waar mogelijk kwanitificeert de effecten van de aanleg van een luchthaveneiland in de Noordzee op de ecologie van strand en duin. De belangrijkste effecten van een eiland in de Noordzee op strand en duin, zijn gelegen in veranderingen in kustmorfologie en saltspray. Veranderingen in de morfologie hebben het grootste effect op het strand (en zeereep) en veranderingen in saltspray op de vegetatie in de duinen. Voor strand en zeereep geeft een aanwaskust in de luwte van het eiland mogelijkheden voor natuurontwikkeling, maar voor de duinen betekent de afname van saltspray een achteruitgang in natuurbehoudswaarde van deze internationaal beschermde gebieden.