Dune Ecosystem Research Articles

Coupled simulation of percolation and evapotranspiration in semi-mobile and semi-fixed dunes

Accurately describing the important components of the water balance, such as precipitation (P), deep percolation (D), and evapotranspiration (ET) and their relationships is crucial for understanding the water cycle and eco-hydrological processes in arid and semi-arid regions. This study coupled the dual crop coefficient model (Dualkc) with the HYDRUS-1D model to simulate D and ET processes in the semi-mobile and semi-fixed dune ecosystem in China’s Horqin Sandy Land during the growing seasons from 2015 to 2022. The results indicated that the improved HYDRUS-1D model achieved high simulation accuracy at a daily scale, with the R2 of 0.83, RMSE of 0.392, NSE of 0.714, and b of 0.828, representing increases of 15.27%, 20.16%, 16.01%, and 5.6%, respectively, compared to the original model. ET and D constituted the primary water dissipation processes in semi-mobile and semi-fixed dunes, accounting for 97% to 99% of P during the growing season. The evaporative ratio (ET/P) ranged from 46.7% to 79.3%, averaging 65.67% over multiple years, and the deep percolation ratio (D/P) varied between 16.1% and 53%, averaging 31.02%. The distribution of precipitation events, soil water content, and vegetation conditions are critical factors affecting ET and D in arid and semi-arid dune ecosystems. This study is of great significance for a deep understanding of the eco-hydrological processes in the dune ecosystem, and it can provide important support in developing water management strategies in the desertification region.

The Environmental Legal Framework of Mexican Caribbean Dunes: A Retrospective Case Study of Vegetation and Coastal Dune Loss in the Sian Ka’an Biosphere Reserve

The Mexican Caribbean coastal dune is protected by national and international environmental legislation. However, through permits, concessions and authorizations for changes in land use, the coastal dune has been fragmented or suppressed, mainly for touristic activities, causing a decline in protective and ecological ecosystem services. In this study, we evaluated the strength and weakness of Mexican legislation to protect the Caribbean coastal dune ecosystem and estimated the historical and current effects on coastal dune vegetation and dune geomorphology, associated with legal allowances of land use change in the Sian Ka’an Biosphere Reserve (SKBR). Legislation at the federal, state and local level were critically reviewed, and with remote sensing techniques and the Remotely Piloted Aircraft System (RPAS), we conducted a case study in the SKBR to estimate coastal dune vegetation alteration trends during the period 2011–2020 and modifications on the dune geomorphology associated with land use change allowances. At the federal (four laws), state (eight laws) and local (nine Local and Territorial Planning Programs (POEL and POET) levels, we found a lack of consensus and alignment between regulations, starting with a lack of definition of ecosystems subject to protection. For coastal dunes, none of them consider topography, ecological function and a way to identify it in the field, making the surveillance highly complex and favoring land use changes, the removal of vegetation and dune geomorphology alteration. Remote sensing techniques showed that areas with land use authorizations exhibit negative vegetation cover trends (Mann–Kendall <−0.4), indicating a decline in vegetation cover density that is mostly anthropogenically induced. The RPAS analysis demonstrated drastic alterations to complete elimination of the coastal dune geomorphology in areas with land use change. In the Mexican Caribbean, the loss of coastal dune and associated ecosystem by the lack of congruent legislation threatens the environmental stability of the coastal areas.

Mosaic of biological soil crusts and vascular plants contributes to the spatial heterogeneity of key soil properties at different successional stages of restored inland sand dunes

Abstract Background and aims Inland sand dunes constitute Natura 2000 habitat that has become a priority to ensure biodiversity protection and habitat heterogeneity at the landscape scale; however, without proper management, spontaneous succession leads to overgrowing of trees and thus to habitat degradation. Understanding succession processes, relationships between biotic and abiotic components, and their changes over time after restoration, is the key to proper planning of future restoration activities. The aim was to determine the changes of biological soil crust (BSC), vascular plants and physicochemical parameters of BSC, below-crust, rhizosphere, and bare substrate types at different stages of succession in inland dunes of the Błędowska Desert (Poland). We also analyzed the interplay between these factors to further understand the mechanism of BSC development and recognize driving factors causing changes in the soil environment. Results Our results showed that BSCs contributed to increased organic C, total N, nutrients in soil, and acidification with the succession. The content of inorganic N forms was significantly higher in bare soil compared to below-crust soil. Rhizosphere soil was enriched in organic matter and nutrients, which improves soil conditions within plant patches. Moreover, below-crust soil pH, total N content and water holding capacity drive the patterns of BSC morphological groups and species composition of lichens, bryophytes, and vascular plants. Conclusion Our study shows that spatial structure of the inland dune ecosystem is a mosaic of BSCs and plants that contribute to the spatial heterogeneity of key soil properties. We concluded that it is necessary to consider the matter of BSC in restoration treatments.

Human impact on the scenic quality of coastal dunes: A study of the central Caribbean coast of Colombia

This paper provides a scenic assessment of 19 dune sites using the Dune Scenery Evaluation System (DSES). The DSES assesses values from a checklist of 18 physical and 8 human parameters and allows the calculation of a scenic evaluation index (D Value), which classifies D sites into five classes: Class I, usually natural areas of top scenic characteristics, to Class V, poor scenic dune areas with a greater impact of human interventions. Our findings reveal a predominance of coastal dune systems falling into middle to lower scenic quality classes (III, IV, and V), indicating considerable degradation due to intense human activities. Notably, these activities have adversely impacted the structural integrity and scenic value of these dunes, leading to a loss of biodiversity and increased vulnerability to natural hazards. This paper highlights the critical need for integrated coastal management strategies that balance conservation with sustainable development. Furthermore, our study proposes the enhancement of existing regulatory frameworks, community engagement in conservation efforts, and the implementation of ecological restoration projects aimed at reversing the degradation and restoring the ecological and scenic value of these vital landscapes. The findings underline the potential of using scenic quality as an ecological indicator to guide conservation and management practices, ensuring the preservation of coastal dunes, which are essential for ecological sustainability and local economic benefits. This multidisciplinary approach not only enriches our understanding of the complex interactions within dune ecosystems but also sets a precedent for future research and policymaking in coastal zone management.

Integrating UAV imagery and machine learning via Geographic Object Based Image Analysis (GEOBIA) for enhanced monitoring of Yucca gloriosa in Mediterranean coastal dunes

Effective monitoring and early detection of invasive alien plant species (IAPs) are crucial for mitigating their spread and safeguarding native habitats. Unmanned Aerial Vehicles (UAVs) offer a cost-efficient solution, providing high resolution images. In this study, we aimed to develop a semi-automated methodology using a machine learning algorithm, spatial metrics, and clustering techniques on UAV images to monitor, map, and suggest management measures to counteract Yucca gloriosa, an invasive plant colonizing coastal fixed dunes in central Italy.UAV flights were conducted using two drones: one for the visible spectrum and the other for multispectral bands (Blue, Green, Red, Red Edge, and Near Infrared) along with a Digital Surface Model (DSM). Derived vegetation indices were also utilized. For mapping Y. gloriosa distribution, a Geographic Object Based Image Analysis (GEOBIA) approach was applied to the orthophoto segmentation, followed by a Random Forest algorithm in a training phase, considering three variable combinations (DSM + vegetation indices, DSM + spectral bands, DSM + mixed variables). The most accurate Y. gloriosa map was used to suggest management measures combining the spatial pattern of invaded patches (size, height, isolation level, and aggregation degree) and a mixed clustering approach (hierarchical and partitioning).The results highlighted that the most accurate prediction map was based on the DSM + mixed variables dataset, showing the important role of using a combination of spectral bands and vegetation indices. In all three cases, the DSM emerged as the pivotal variable for discriminating Y. gloriosa from the surrounding environment. Additionally, our results demonstrate the advantages of incorporating vegetation indices in discerning the target invasive alien plant (IAP) from the broader environment, particularly considering its distinctive photosynthesis process and biomass production. From a managerial standpoint, our pilot study indicates that the UAV-based mapping methodology represents an optimal balance between field efforts and costs. This approach allows for the precise identification of containment and removal areas of Y. gloriosa, without compromising the accuracy of the method. The generated prediction maps also hold potential significance for the conservation of coastal dune ecosystems, providing a promising tool for the effective management of invasive species and biodiversity conservation by suggesting management measures for Y. gloriosa.

Seawater spray as a significant nitrogen source across coastal dune vegetation gradients

BackgroundNitrogen significantly influences plant performance and vegetation development in nutrient-poor ecosystems like coastal dunes. While various sources contribute nitrogen, including N2 fixation and marine inputs, the significance of seawater spray remains understudied. In this study, we aimed to assess the relevance of seawater spray as a source of nitrogen input and its potential role in plant community composition in dune ecosystems. MethodsThe δ15N, δ13C, N, and C content of leaves from the most abundant 21 species were measured in 6 positions across a beach inland gradient in a Mediterranean dune system in SW Spain. Soil samples at different depths were collected in each position and N, C, P, K, NH4+, NO3=, and organic matter were measured. Salt spray accumulation was determined on Achillea maritima leaves across the gradient. ResultsLeaf nitrogen content did not exhibit a beach-inland gradient, but δ15N decreased with distance from the sea. Species displayed three distinct N uptake strategies along the gradient: species from Upper Beach and Foredune communities showed high δ15N values, suggesting a marine origin; species distributed across the gradient exhibited decreasing δ15N patterns from the Upper Beach to the Inland, indicative of seawater spray influence; species farthest from the sea relied on non-marine nitrogen sources. ConclusionsThese results indicate the importance of seawater nitrogen income for the dune system vegetation and evidence that dune plant species exhibit varied N uptake strategies influenced by their position across the beach-inland gradient.

Decoupling the effects of near-surface characteristic change on soil roughness in a dune-meadow cascade ecosystem

As an important indicator of ecological restoration, soil roughness changes exhibit a synergistic evolutionary relationship with near-surface characteristics such as soil and vegetation. However, the main controlling factors for changes in soil roughness in different ecosystems are still unclear. This study was conducted to clarify the changes in soil roughness in different ecosystems and to decouple and quantify the impact of near-surface characteristics on soil roughness in the Horqin Sandy Land (China). Soil roughness was measured using the structure-from-motion (SfM) technique, showing a pattern of farmland (14.08 mm) > semi-mobile dune (12.59 mm) > meadow (6.19 mm) > woodland (5.67 mm). Redundancy analysis (RDA) results showed that the near-surface characteristics of the dune-meadow cascade ecosystem that explained soil roughness, in descending order of importance, were as follows: sand, soil moisture content (MC), silt, plant stem diameter (SD), clay, pH, soil organic matter (SOM), soil shear resistance (SC), litter thickness (LT), water-stable aggregates (WSA), litter density (LD) and bulk density (BD). Specifically, in the semi-mobile dune ecosystem, the order of total effects on soil roughness was as follows: sand (1.311) > pH (0.447) > clay (0.387). In the woodland ecosystem, SC (0.226), pH (|-0.216|), and LD (0.179) were important factors controlling soil roughness. In the farmland ecosystem, MC (0.380), LT (|-0.378|), and SOM (|-0.336|) were the main controlling factors of soil roughness. In the meadow ecosystem, silt (0.574), SOM (|-0.413|), and clay (|-0.380|) significantly influenced soil roughness. Compared to other machine learning models and stepwise regression models, the k-nearest neighbors (KNN) model could predict soil roughness changes more accurately. The findings of this research are of great significance for ecological restoration and sustainable development of the ecologically fragile areas in northern China.

Low impact of Carpobrotus edulis on soil microbiome after manual removal from a climate change field experiment

Synergic effects between climate change and invasive species may alter soil microbial diversity and functioning, as well as cause major shifts in physicochemical properties. Moreover, some of these ecological impacts may manifest even after the removal of the invasive species. We have conducted a field experiment to assess such effects on soil microbial communities (fungi and bacteria) and physicochemical properties seven months after the removal of Carpobrotus edulis (L.), an invasive plant of coastal dune ecosystems. C. edulis grew on the experimental plots for 14 months under current (“invasive species treatment”) and increased warming and drought conditions (“combined treatment”). Then, all plant parts (above and belowground biomass) were removed with a non-aggressive eradication method and soil samples were collected seven months later in the experimental and control plots (no invasive species and current climatic conditions). We predicted a general compositional shift in microbial communities in response to the presence of the invasive species. Moreover, given that water is the most limiting factor in this type of ecosystem, we also predicted a more pronounced compositional shift in the treatment combining invader presence and climate change. While species richness was similar amongst treatments, we observed some taxonomic and functional variation in soil microbial communities. Notably, fungal and bacterial communities exhibited contrasting responses. The species composition of bacteria differed significantly between the “invasive species” and “control” treatments, while, in the case of fungi, the most substantial difference occurred between the “invasive species” treatment and the combined treatment of “invasive species and climate change”. Some chemical properties, such as carbon and nitrogen content or pH, strongly differed amongst treatments, with the “invasive species” showing a different response compared to the other two treatments. Overall, our study suggests smaller short-term effects on the microbial community compared to soil chemical properties. Furthermore and contrary to our initial expectations, the potential impact on the soil microbiome seemed to be weaker in the face of rising temperatures and drought conditions predicted by climate change. This outcome highlights the remarkable complexity of the impact of invasive species and climate change on belowground microbial communities.

Permanent loss of barrier island resilience due to a critical transition in dune ecosystems

Barrier islands cover a large fraction of US coasts and support unique ecosystems and coastal infrastructure. The ‘barrier’ function of a barrier island depends on coastal dunes that can prevent storm flooding and widespread ecosystem loss. Furthermore, dune-less barriers are more susceptible to breaching and potential drowning under sea level rise. Here we study the transition from richly-vegetated barriers with mature dunes (‘high’ state) to dune-less barren barriers (‘barren’ state) using data from a representative set of barrier islands in Virginia, US. We find that these two states are possible stable solutions of a non-linear stochastic dynamics characterized by a tipping point at which barriers with elevation around beach berms experience a critical transition into a permanently barren state. Our results suggest that frequently-flooded dune-less barren islands are a natural endpoint of barrier’s evolution under sea level rise.

A Synthetic Framework to Match Concepts and Approaches When Managing Anthropogenic Threats

Anthropogenic threats impacting ecological targets should be mitigated and solved using fast and schematic tools useful in conservation strategies. Herein, we suggest a mixed and quick approach implementing coarse-grained (and expert-based) threat analysis with the fine-grained (and analytical) DPSIR (driving forces, pressure, status, impact, and response) framework of indicators, all included in a single causal chain. Both approaches are largely used in conservation but never combined. A simulated example of the application of the set of indicators (status, pressure, impact, and response) on dune ecosystems (and nested targets represented by halo-psammophilous plants) has been included. Due to its schematic format, values as targets, pressures as threats, and responses as conservation strategies have been unified in a single conceptual framework. This synthetic framework can also be used to communicate to academic students the complexities of socio-ecological systems on the conservation front lines using a simplified cause–effect chain.

Containing alien plants in coastal dunes: Evidence from a soil manipulation experiment

Biological invasion is recognised as one of the major threats to biodiversity, particularly in disturbance-prone ecosystems such as costal dunes. Many studies have associated alien plant invasion of dune ecosystem to human disturbances, but less is known about the role of soil properties in invasion after disturbance. Soil properties are crucial filters during plant succession and soil-related changes in the initial stage of species colonization might shape the final success of the invaders.We performed a manipulative experiment aimed at elucidating the effects of soil properties on plant colonization processes in highly invaded dune systems, as a proxy for plausible management actions to curb the success of exotic plant species over native ones, which was measured through species richness and abundance.In a barrier island of the Marano and Grado lagoon, Northern Adriatic Sea, we mechanically removed all the native and alien vegetation present in the back dune (also known as secondary dune), triggering a new ecological succession and further altered, for the following three months, soil properties by adding salt, nitrogen, and organic matter in a full factorial design with randomized blocks.The soil treatments reduced the overall species richness and abundance of alien plants. Further, soil treatment interactions strongly shaped community evenness and species richness. Soil salinity had a positive effect on native cover while decreasing the overall number of alien species, especially in soil with added organic matter.Our findings suggest that soil salinity, and its interplay with organic matter, might significantly reduce the initial success of alien species propagule pressure (i.e. alien plant germination), with likely implications for the trajectories of future plant communities. This study highlights that alien plant containment should be focused on early stages of succession, giving new perspective on future environmental management actions for dune restoration and conservation.

Pinus banksiana Lamb. Regeneration Patterns in a Lacustrine Dune System

Successional patterns in lacustrine sand dunes along Lake Superior begin with grass-dominated plant communities leading to the establishment of Pinus banksiana Lamb. as initial forests. Using maximum entropy models, we predicted P. banksiana seedling and sapling patterns within the Grand Sable Dunes, Pictured Rocks National Lakeshore, USA, based on slope, aspect, forest basal area, and vegetation types. Across the different vegetation types, there were variable probabilities of seedling and sapling occurrence. For both seedlings and saplings, the higher likelihoods of occurrence were observed in coastal pine barrens vegetation types. P. banksiana regeneration is occurring in the Grand Sable Dunes in the absence of fire, with seedlings establishing and saplings being recruited in a variety of vegetation types. With the greatest probabilities in barrens, there is likely a relationship with seed source and canopy density. Understanding regeneration patterns in dune ecosystems is necessary to predict the future forest arrangement and colonization of P. banksiana into the dunes. These results contribute insights into the dynamics of plant communities in lacustrine dune systems, specifically the establishment of P. banksiana seedlings in various vegetation types. Continued forest establishment and increasing P. banksiana density will influence endangered species and non-native species management strategies for Pictured Rocks National Lakeshore.

Enhancing precision in coastal dunes vegetation mapping: ultra-high resolution hierarchical classification at the individual plant level

ABSTRACT The classification of ultra-high-resolution (UHR) imagery, characterized by spatial resolutions exceeding 10 cm, presents opportunities and challenges distinct from lower-resolution counterparts. Particularly, challenges are pronounced in some scenarios, such as mapping plant species in coastal environments, where similar vegetation responses and small plant sizes pose additional difficulties. The present work addressed such issues by developing a UHR vegetation cover classification model at the single plant level using data from uncrewed aerial systems (UASs) equipped with a multispectral optical sensor. The model was tested across the San Rossore Regional Park (Italy), where three pilot areas were defined as training-test-validation sites. The proposed solution consists of a hierarchical two-level-of-detail machine learning model based on object-based image analysis (OBIA) and random forest. This model considers spectral features and indices, elevation, and texture and can classify twelve plant species and two service classes (debris and sand) within the study areas. Train and test were carried out utilizing UAS flight data collected during two specific phenological periods and precise field data derived from in-situ vegetation surveys, which provided 937 herbaceous and shrub samples. The model performance was evaluated based on the error matrix and 50-fold stratified cross-validation method, obtaining an overall accuracy (OA) of 0.76 and a standard deviation of 0.08. Such assessment underscored the crucial role of texture information, in addition to radiometric and elevation. Finally, the model was tested against an unseen dataset, proving its transferability (OA equal to 0.62). Although the discussion highlights some aspects to be further improved and claims for future research, the first version of this hierarchical classification model demonstrated its potential for mapping and monitoring coastal sand dune ecosystems, providing data for understanding and, eventually, modeling ecological and biogeomorphological dynamics.

Effect of glyphosate on germination and seedling development of four native plants of dunes in Spain

Using glyphosate is easier than manually controlling the invasive plant Carpobrotus in dune ecosystems. However, before it is used its effect on native species in this ecosystem needs to be determined. This study reports the effects in the laboratory of different concentrations of glyphosate (1.0, 0.5, 0.3, 0.1, 0.05, 0.01, and 0.005 g/m2 ) on germination and seedling emergence of four species of Mediterranean dune plants, Lotus creticus, Medicago marina, Ononis ramosissima and Ammophila arenaria, used in the restoration of this natural ecosystem. Germination was completely inhibited when glyphosate was applied at 0.5, and 1.0 g/m2. The recommended dose (0.3 g/m2 ) also inhibited the germination of L. creticus and M. marina. The percentage germination of O. ramosissima and A. arenaria was around 40% and 30% respectively when a dose of glyphosate of 0.1 g/m2 was used, whereas for seeds of L. creticus and M. marina it was lower than 5%. The T50 at germination of seed incubated with glyphosate increased in all species independently of the dose of glyphosate. Seedling emergence from seeds previously germinated in the presence of glyphosate was only recorded for O. ramosissima and A. arenaria. The results indicate that seeds of O. ramosissima are more tolerant of glyphosate, followed by those of A. arenaria and those of L. creticus and M. marina are the most sensitive.

Ecological status of a retired mine lake in a protected dune ecosystem

ABSTRACT Ottawa Sands Lake is a retired mine lake located in a protected dune ecosystem adjacent to Lake Michigan in western Michigan, USA. Development activities are planned for the lake and surrounding land, potentially threatening the lake’s ecological health. We conducted a baseline study of water quality and macroinvertebrates, combined with exclusion cage experiments, to examine the role of predation. Our results indicated the lake’s littoral zone had good water quality with low phosphorus (mean soluble reactive phosphorus [SRP] < 5 µg/L; mean total phosphorus [TP] < 10 µg/L) and nitrogen (mean nitrate [NO3-N] = 38–190 µg/L; mean ammonia [NH3-N] = 8–19 µg/L, excluding deep hole) concentrations, high dissolved oxygen (>9.5 mg/L, excluding deep hole), and low chlorophyll a (<12 µg/L, except for 1 sampling date) concentrations. The macroinvertebrate community was dominated by 9 families, with Chironomidae the most abundant. Three environmental factors—specific conductivity, total dissolved solids, and ammonia—were significantly related, albeit weakly, to macroinvertebrate community structure. The exclusion cages did not result in a statistically significant difference in macroinvertebrate community structure, although high variance may have masked differences. Overall, Ottawa Sands Lake is a high-quality system, but development plans, including the installation of a paved trail around the lake and the implementation of a nonmotorized boating program, may result in changes. The baseline conditions outlined in this work will allow lake managers to assess the impact of development activity and add to the limited database regarding the limnology of retired mine lakes around the globe.

Fungal communities are passengers in community development of dune ecosystems, while bacteria are not.

An increasing number of studies of above-belowground interactions provide a fundamental basis for our understanding of the coexistence between plant and soil communities. However, we lack empirical evidence to understand the directionality of drivers of plant and soil communities under natural conditions: 'Are soil microorganisms driving plant community functioning or do they adapt to the plant community?' In a field experiment in an early successional dune ecosystem, we manipulated soil communities by adding living (i.e., natural microbial communities) and sterile soil inocula, originating from natural ecosystems, and examined the annual responses of soil and plant communities. The experimental manipulations had a persistent effect on the soil microbial community with divergent impacts for living and sterile soil inocula. The plant community was also affected by soil inoculation, but there was no difference between the impacts of living and sterile inocula. We also observed an increasing convergence of plant and soil microbial composition over time. Our results show that alterations in soil abiotic and biotic conditions have long-term effects on the composition of both plant and soil microbial communities. Importantly, our study provides direct evidence that soil microorganisms are not "drivers" of plant community dynamics. We found that soil fungi and bacteria manifest different community assemblies in response to treatments. Soil fungi act as "passengers," that is, soil microorganisms reflect plant community dynamics but do not alter it, whereas soil bacteria are neither "drivers" nor "passengers" of plant community dynamics in early successional ecosystems. These results are critical for understanding the community assembly of plant and soil microbial communities under natural conditions and are directly relevant for ecosystem management and restoration.

Larval diet of the carpenter bee Xylocopa (Neoxylocopa) cearensis (Hymenoptera: Apidae: Xylocopini) from the Delta do Parnaíba environmental protection area, Brazil

The genus Xylocopa Latreille, 1802 (Apidae: Xylocopini) Latreille includes efficient pollinating bees that visit a wide range of botanical species. Although several studies have investigated their interactions with plants in dune ecosystems, there is still a limited understanding of these bee communities in coastal environments. This study aimed to characterize the larval diet of Xylocopa (Neoxylocopa) cearensis Ducke, 1910 by analyzing pollen from their nests to assess the presence of specialization or generalization in relation to botanical species. The research was carried out in coastal sandbanks of the Delta do Parnaíba Environmental Protection Area, Tutóia, Maranhão-BR, over a 12-month period. The natural nests were inventoried by active searches and, when possible, transported to the Federal University of Maranhão. Pollen samples were collected from 19 brood cells of 12 nests in total. All the nests were found on branches of Anacardium occidentale L. Using the acetolysis method, 21 types of pollen were recognized, representing 14 botanical families. Three of those types of pollen were considered to be Frequent pollen, Mouriri cearensis Huber (35.44%), Chamaecrista ramosa (Vogel) H. S. Irwin & Barneby (32.80%) and Myrcia multiflora (Lam.) DC (27.05%). Based on these results, X. cearensis can be characterized as a polylectic species that demonstrates adaptability. These floral resources serve as essential protein sources for the nutrition of their brood, highlighting the importance of these plant species in supporting their reproductive success. This study provides useful information that can serve as a reference for future research on other Xylocopa species in similar ecosystems.

Implementing a vegetation-based risk index to support management actions in Mediterranean coastal dunes

Coastal dunes play a crucial role in mitigating sea-related impacts and safeguarding coastlines. However, increasing human influence and natural factors such as sea-level rise underscore the need for effective coastal risk assessment methodologies. This study introduces a comprehensive coastal risk index covering 24 km of the Italian coastline within the protected area of San Rossore Park (Tuscany, Italy). The study area, distinguished by its notable coastal dune ecosystems, holds naturalistic, cultural, and economic importance. Nevertheless, diverse uses, zoning, and human impact variables pose challenges.By incorporating geological, socioeconomic, cultural, and ecological parameters, the index integrates a range of data sources and field observations. This research focused on developing and applying a vegetation-based risk index (VRI) within a geographic information system (GIS) framework, recognizing the ecological importance of dune vegetation in mitigating coastal erosion. Analysisrevealed varying risk levels within the study area. Half of the San Rossore Park coastline exhibited low risk values, 37.5% had moderate risk values, and 12.5% had high risk values. The publicly accessible northernmost section displays excellent preservation of dune habitats but faces heightened risk due to anthropogenic impacts. Conversely, the central-southern portion, inaccessible to the public, registers high-risk levels linked to variables associated with coastal erosion.Furthermore, the results highlight areas with heightened cultural and ecological vulnerabilities aligned with elevated risk levels. The index facilitates clear and intuitive cartographic representations of coastal risk, identifying variable categories that substantially influence on risk determination. Tailored strategies, including mitigating human pressure in the northern sector and implementing erosion management in the central-southern region, are recommended.In summary, this study not only provides a practical tool for assessing and managing coastal areas and directing attention to specific threats but also supports stakeholders in informed decision-making. The VRI enhances global sustainable coastal conservation, deepening our understanding of coastal risks and providing valuable insights for effective management strategies.

Digital Elevation Models and Orthomosaics of the Dutch Noordwest Natuurkern Foredune Restoration Project

Coastal dunes worldwide are increasingly under pressure from the adverse effects of human activities. Therefore, more and more restoration measures are being taken to create conditions that help disturbed coastal dune ecosystems regenerate or recover naturally. However, many projects lack the (open-access) monitoring observations needed to signal whether further actions are needed, and hence lack the opportunity to “learn by doing”. This submission presents an open-access data set of 37 high-resolution digital elevation models and 24 orthomosaics collected before and after the excavation of five artificial foredune trough blowouts (“notches”) in winter 2012/2013 in the Dutch Zuid-Kennemerland National Park, one of the largest coastal dune restoration projects in northwest Europe. These high-resolution data provide a valuable resource for improving understanding of the biogeomorphic processes that determine the evolution of restored dune systems as well as developing guidelines to better design future restoration efforts with foredune notching.

Status of the invasion of Carpobrotus edulis in Uruguay based on citizen science records

Carpobrotus edulis, a highly invasive plant species repeatedly introduced along the Atlantic coast of South America, poses a significant threat to the ecological integrity of coastal dune ecosystems in Uruguay. This study used 15 years of iNaturalist records to assess the magnitude of Carpobrotus invasion, focusing on its distribution, abundance, and reproductive phenology. Through the analysis of georeferenced and dated data, we determined that Carpobrotus has spread extensively, covering a 10-km-wide coastal area and occupying approximately 220 km along the Atlantic coast and the outer Rio de la Plata estuary. Records have increased in the last three years, with a summer prevalence of 52.9%, due to higher activity on the platform. The species exhibited two flowering peaks in spring and autumn, suggesting an extended reproductive period. The widespread presence of this species in both natural and urbanized areas highlights the urgent need for effective management strategies to mitigate its impact on native biodiversity. Utilizing citizen science platforms like iNaturalist has been instrumental in monitoring and documenting processes of invasion. However, further investigations are necessary, particularly in less sampled regions, to fully understand the extent of Carpobrotus invasion. To protect the country’s coastal ecosystems, it is crucial for local authorities to reassess current practices related to non-native species ornamental planting. By addressing the invasion of C. edulis, the ecological integrity of coastal dune ecosystems can be preserved, ensuring the survival of native flora and fauna along Uruguay’s Atlantic coast.