Effects of trampling limitation on coastal dune plant communities

Ecophysiological performance of terrestrial diatoms isolated from biocrusts of coastal sand dunes

Terrestrial diatoms are widespread in a large variety of habitats and are regularly recorded in biocrusts. Although diatoms have long been known to live in terrestrial habitats, only a few studies have focused on their diversity of ecophysiology. Here we present a study on the ecophysiological performance of five terrestrial diatom cultures from biocrusts, which were collected in sand dunes of the German coast of the Baltic Sea. The sampling sites were selected along a gradient of human impacts on the dunes. The richness of diatom species, roughly estimated from permanent slides, was around 30 species per sampling site. The species abundance was calculated in the same way revealing a high proportion of broken diatom frustules. All diatom cultures established in the laboratory showed no photoinhibition and high oxygen production along a light gradient. The desiccation tolerance differed among the strains, with high recovery observed for Hantzschia abundans and Achnanthes coarctata and low to no recovery for Pinnularia borealis and Pinnularia intermedia. The maximum growth rate for most strains was between 25 and 30°C. These temperatures can be easily reached in their natural environments. Nevertheless, during short-term exposure to elevated temperatures, oxygen production was recorded up to 35°C. Interestingly, two of five diatom cultures (Hantzschia abundans and Pinnularia borealis) produced mycosporine-like amino acids. These UV-protective substances are known from marine diatoms but not previously reported in terrestrial diatoms.

Dune plants as a sink for beach litter: The species-specific role and edge effect on litter entrapment by plants

Anthropogenic litter accumulates along coasts worldwide. In addition to the flowing litter load, wind, sea currents, geomorphology and vegetation determine the distribution of litter trapped on the sandy coasts. Although some studies highlighted the role of dune plants in trapping marine litter, little is known about their efficiency as sinks and about the small-scale spatial distribution of litter across the dune area. Here, we explore these gaps by analysing six plant species widespread in Mediterranean coastal habitats, namely Echinophora spinosa, Limbarda crithmoides, Anthemis maritima, Pancratium maritimum, Thinopyrum junceum, and Salsola kali. The present study analyses for the first time the capture of litter by dune vegetation at a multi-species level, considering their morphological structure. Data on plastic accumulation on dune plants were compared with unvegetated control plots located at embryo-dune and foredune belts. We found that dunal plants mainly entrapped macrolitter (> 0.5 cm). Particularly, E. spinosa, L. crithmoides, A. maritima and P. maritimum mostly accumulated litter in the embryo dune while T. junceum and S. kali entrapped more in the foredune area. Moreover, beach litter was mainly blocked at the edge of the plant patches rather than in the core, highlighting the 'Plant-edge litter effect'. As A. maritima and S. kali entrapped respectively more litter in embryo and foredune habitats, these species could be used to monitor and recollect litter. In this light, our findings provide further insight into the role of dune plants in the beach litter dynamics, suppling useful information for beach clean-up actions.

Spatial variation of soil seed banks along a gradient of anthropogenic disturbances in tropical forests on coral islands

Poor regeneration of natural vegetation is a major factor contributing to the degradation of tropical coral islands. Soil seed banks (SSB) are important for maintaining the resilience of plant communities. However, the community characteristics and spatial distribution of SSBs and the controlling factors along human disturbance on coral islands are unclear. To fill this gap, we measured the community structure and spatial distributions of forest SSBs on three coral islands in the South China Sea, with varying degrees of human disturbance. The results showed that strong human disturbance increased the diversity, richness, and density of SSBs, as well as increased the richness of invasive species. With increased human disturbance, the heterogeneity pattern of SSBs spatial distribution changed from difference between forest east and west to forest center and edge. The similarity between the SSBs and above-ground vegetation also increased, and the distribution of invasive species extended from the edge to the central area of the forests, demonstrating that human disturbance limited the outward dispersal of seeds of resident species but increased the inward dispersal of seeds of invasive species. Interaction between soil properties, plant characteristics, and human disturbance explained 23-45% of the spatial variation of forest SSBs on the coral islands. However, human disturbance reduced the correlations of plant communities and spatial distribution of SSBs with soil factors (i.e., available phosphorus and total nitrogen) and increased the correlations of the community characteristics of SSB with landscape heterogeneity index, road distance, and shrub and litter cover. Resident seed dispersal on tropical coral islands might be enhanced by reducing building height, constructing buildings in down-wind locations, and preserving corridors that support animal movement among forest fragments.

Dunal plants as sink for anthropogenic marine litter: The entrapping role of Salsola kali L. (1753) in a Mediterranean remote beach (Sardinia, Italy)

The ability to retain anthropogenic marine litter by a halo-psammophilous plant formation dominated by a single prostrate species (Salsola kali) on a Sardinian beach was measured. We hypothesized that the anthropogenic litter (i) is trapped by plants to a greater extent than in control areas, and (ii) has more elongated size, mimicking the organic Posidonia wrack, largely occurring locally as 'banquettes'. Salsola kali patches show an apparently higher anthropogenic litter density than control sites without vegetation. Salsola kali plants trap litter items significantly longer and a larger number of size length categories than control plots. These effects may be due to the prostrate structure of the plant with small thorns at the apex. Also, litter entrapped by plants can interfere with the mechanisms of dune deposition and structuration, in turn affecting food chains by decreasing the availability of organic material for pedofauna.

General macro-litter as a proxy for fishing lines, hooks and nets entrapping beach-nesting birds: Implications for clean-ups

Fishing lines, hooks and nets represent a sub-category of macro-litter potentially entrapping plover birds nesting on sandy beaches. Here, during a winter period, the accumulation pattern of both general beach litter and fishing lines, hooks and nets was analysed on four central Italy beaches. Despite the active monthly litter removal by clean-ups, there was not a decrease in its density during the winter period, due to the continuous accumulation by frequent winter storms. However, the entrapping litter was very low (<2.5 % of the general litter) and appeared directly correlated to the general litter density. Following a DPSIR approach, the general litter can act as an indirect pressure indicator (proxy) of the amount of entrapping litter. Therefore, an increase in general macro-litter should alarm those involved in the conservation of entanglement-sensitive bird species, such as plovers, suggesting that they should implement high-frequency clean-up activities aimed at removing it.

A “diary of events” to support the management actions on two beach-nesting birds of conservation concern: Historicization of experiences, learned lessons, and SWOT analysis

During the project management actions, a chain of fine-grained events occur, both of bio-ecological and anthropic origin. While some may be expected or planned, others may be unforeseen. This work proposes the drafting of a ‘diary of events’ reporting bio-ecological and anthropogenic events, these last having both negative and positive impacts. This diary can be carried out using a schematic form, aiming to highlight the cause-effect relationships between events, the management responses, and the lessons learned. Analyzing the strengths, weaknesses, opportunities, and threats (i.e., the internal and external conditioning factors) linked to these events (SWOT analysis) to make a case of study from the real world, we applied this approach to a project aimed at protecting nests of two species of conservation interest (Charadrius alexandrinus and C. dubius) in a protected coastal area of central Italy.

Temporal changes of plastic litter and associated encrusting biota: Evidence from Central Italy (Mediterranean Sea)

We investigated the temporal changes from spring to summer of the stranded litter and the composition of plastic encrusting biota along an Italian beach. Our findings highlight a higher quantity of litter (average value 1510.67 ± 581.27 items) in spring, particularly plastic material with a composition driven by currents, winds and waves transported from rivers to sea. During summer the source was caused by anti-social behaviours (e.g. cigarettes). Regarding the plastic size, the most is macroplastic (85.96 %), followed by mesoplastic (13.74 %) and megaplastic (0.30 %) overall, and no seasonal trend was observed. Concerning the encrusting biota, Mollusca was the most frequent phylum found on plastic beach litter, whereas Porifera the most abundant overall. During spring a greater abundance of individuals was recorded compared to summer. The trend of taxa richness was decreasing from spring to summer. Arthropoda, Porifera and Mollusca phyla were significantly more abundant in spring, while Algae in summer.

Impact of Horse Grazing on Floristic Diversity in Mediterranean Small Standing-Water Ecosystems (SWEs)

Small standing-Water Ecosystems (SWEs), despite their pivotal ecological role due to their participation in hydrogeological processes and their richness in biodiversity, seem to be often overlooked by the scientific community. In this study, the vascular plant diversity in some representative SWEs, that host a peculiar assemblage of plant and animal species, was investigated in relation to the disturbance effects of a wild horse population. A total of 50 plots, equally distributed in small and large SWEs, were surveyed and a level of disturbance was attributed to each plot. We found greater species richness in small and undisturbed SWEs, which suggests the negative impact of horse grazing on the richness of plant species in this type of habitat. Significant differences in plant assemblage were found according to the disturbance level, whereas, contrary to what was observed for species richness, no differences were detected based on their size. The diversity indices, used to evaluate the richness and diversity in these areas, recorded the highest values for small and undisturbed areas. This result highlights that the disturbance of the horse grazing plays a pivotal role in affecting the diversity and richness of species in the SWEs. These findings suggest that SWE systems should be analyzed considering these areas as unique in order to allow the conservation of the plant richness and biodiversity of the SWE systems in conjunction with the protection of horses.

Human-derived effects and failure in management drive coastal urban foredune degradation and novel vegetation structure

Urbanization can drive significant decay in species diversity and abundance; in dune ecosystems the composition changes at a pace with changes in spatial fragmentation. Infrastructure deployment and human activities may provoke synergistically a reduction in dune patch size and/or habitat loss and thus a potential for rapid establishment of exotic species, producing a 'novel' habitat configuration. In this study we examine the effects of coastal urbanization and associated human activities in foredune patch fragmentation and changes in floristic composition and abundance in an urban-rural gradient. Using samples from a recently bulldozed and managed urban foredune area, we assess the legacy of erroneous practices associated with planting of exotic species in urban settings. We found a significant increase in foredune fragmentation, estimated as the occurrence of marks left by vehicles (4WD, 2WD) and people in foredunes close to or within urban settings. A marked change from native to non-native plant species was found from rural to urban environments, with non-native species contributing to increase species richness in urban settings. A positive relationship of non-native species with level of foredunes fragmentation was found. Dominance of non-native species was persistent through time in altered foredune patches. Our findings showed that incorporation of non-native species for aesthetic or engineering purposes in bulldozed foredunes, could limit colonization of native species through rapid establishment and complete dominance of non-native ones. Historical activities associated with coastal infrastructure upgrades seem to configure the present foredune floristic pattern present in urbanized coasts. Management strategies correcting past erroneous actions and promoting foredune rehabilitation could help the conservation of services that these 'novel' habitats provide in coastal urban environments.

Effects of land use change on population survival of three wild rice species in China since 2001

Land use change stemming from human activities, particularly cropland expansion, heavily threatens the survival of crop wild relatives that usually occur nearby or scatter in farming systems. Understanding the impacts of land use change on wild populations is critical in forming the conservation decision-making of wild relatives. Based on the investigations on the population survival of three wild rice species (Oryza rufipogon, O. officinalis, and O. granulata) in China over the past 40 years (1978-2019), the effect of land use change during the past 20 years (2001-2019) on the natural populations of the three species was examined using the land use type data of satellite-based Earth observations (data from GlobCover). From 1978 to 2019, the number of populations (distribution sites) of the three wild rice species had decreased by 65-87%, mainly because of the habitat destruction or disappearance caused by human-induced land use change. The three wild rice species display different habitat preferences, resulting in specific land use types surrounding their populations. In the recent 20 years, although the surrounding community composition of the wild rice population has been relatively stable, the surrounding vegetation cover area of the survived populations was significantly more extensive than that of the extinct ones (p < 0.05). These findings suggest that habitat vegetation plays a "biological barrier" role in the survival of wild populations through resisting or mitigating the disturbing impact of land use change on wild populations. This study provides not only direct guidelines for the conservation of wild rice but also new insights into the mechanisms underlying the influence of land use change on wild populations.

Carpobrotus spp. patches as trap for litter: Evidence from a Mediterranean beach

Dunal plants may affect the patterns of deposition of beach litter. In this study, we aimed at evaluating if Carpobrotus spp. patches may act as a litter trap in coastal dune systems. To do so, we counted the number of macrolitter occurring in both Carpobrotus and control (embryo dune vegetation) patches classifying each item into categories according to the Marine Strategy. Totally, we observed a significant difference between litter trapped in Carpobrotus (331 items, representing 62.4% of the total beach litter) and control (199, 37.6%). Plastic fragments were the most trapped items by both Carpobrotus (46.2%) and control patches (47.2%). We also calculated the item co-occurrence, obtaining a random aggregated 'litter community'. The main emerging output is that Carpobrotus patches act as filter in respect to different anthropogenic materials (overall plastics), suggesting that alien plant management actions may contribute to solve beach litter issues as well.

From Citizen Science to Citizen Management: Suggestions for a pervasive fine-grained and operational approach to biodiversity conservation

Citizen Science involves people as part of a scientific enquiry. However, in an age of great environmental changes, citizens are faced with degradation that affects ecosystem structure and function. Their role as drivers of change can be also relevant for biodiversity conservation. As in Citizen Science, where the citizens, properly trained, can initiate a widespread and fine-grained knowledge process, it is also possible to start a Citizen Management process, where citizens, adequately trained in problem solving, can change the state of an environmental system, with positive effects on the latter and on themselves. To prepare citizens for the acquisition of a problem solving and management paradigms, a quick meeting carried out with citizens by a senior manager as facilitator can be an opportunity to explain some basic steps: introducing them to the concept of ‘problem’, the definition of a project team and SMART objectives, the use of creativity during brainstorming, choosing an approach to the decision-making process and defining a strategy (actions, times, roles, resources, monitoring, and adaptation). According to the Hill and Westbrook’s SWOT approach, we suggest a list of strengths, weaknesses, opportunities and threats that characterize the Citizen Management approach.

Assessing effectiveness of exclusion fences in protecting threatened plants

Overgrazing stands out as threat factors on biodiversity, being especially harmful in the Mediterranean, due to strong human pressure and an accelerated climate change acting synergistically. Fencing is a common tool used in conservation biology to tackle this problem. Advantages of fences are usually fast, intuitive, and easy to evaluate. However, disadvantages could also arise (increasing interspecific competition, disturbing habitat structure, limiting pollination, reducing dispersion). Together with management issues (maintenance, conflicts with stakeholders, and pulling effect). Effectiveness of fencing for conservation has been frequently assessed for animals, while it is almost a neglected topic in plants. We evaluated the outcome of fencing three threatened and narrow-endemic plants. Selected 5 populations were only partly fenced, which allowed comparing different variables inside and outside the fence. For evaluating the fencing effects, we sampled several habitats (vegetation cover, composition, density of target species), and target-species features (individual size, neighbouring species, and fruit-set). Fencing had strong effects on the habitat and on target-species individuals, showing contrasting responses at species and population level. Particularly, for Erodium cazorlanum, fence had a positive effect in one case, and negative in another. In Hormathophylla baetica effect was positive in all populations. Finally, fencing negatively affected Solenanthus reverchonii by increasing competition and limiting seed-dispersal. Fencing outcome was different in assessed species, highlighting the need to a case-by-case evaluation to determine the net balance (pros vs. cons), also its suitability and most favourable option (i.e. permanent vs. temporary fences).

A Hybrid Method for Citizen Science Monitoring of Recreational Trampling in Urban Remnants: A Case Study from Perth, Western Australia

Vegetation trampling that arises from off-trail excursions by people walking for recreation can negatively impact the structure of understory plants in natural spaces that are an essential element of urban green infrastructure in a modern city. In addition to reducing the esthetic quality and environmental values of urban remnant and replanted native vegetation, such trampling reduces the habitat that supports wildlife populations within the urban fabric. This case study draws upon several disparate methods for measuring vegetation structure and trampling impacts to produce a hybrid method that community-based citizen scientists (and land managers and other researchers) could use to simply, rapidly, and reproducibly monitor how trampling associated with urban recreation trails impacts the structure of understory vegetation. Applying the novel hybrid method provided evidence that trampling had reduced the vegetation structure adjacent to a recreational walking trail in an urban woodland remnant in Perth, Western Australia. The hybrid method also detected ecological variability at the local ecosystem-scale at a second similar woodland remnant in Perth. The hybrid sampling method utilized in this case study provides an effective, efficient, and reproducible data collection method that can be applied to recreation ecology research into aspects of trampling associated with trail infrastructure.

Small Environmental Actions Need of Problem-Solving Approach: Applying Project Management Tools to Beach Litter Clean-Ups

Clean-ups can be considered real conservation actions since beach litter may impact many ecosystem components. However, although these actions are quite easy to carry out, we think that they need to follow specific criteria and clear planning. Contrariwise, an unplanned clean-up could lead to counter-productive—or even harmful—consequences to the fragile dune ecosystem; e.g., excessive trampling and/or extreme sand removal. Here, we defined a road map for implementing beach clean-ups according to the logic of problem solving and project management, also adding a flow chart. More particularly, we subdivided the clean-up project into different steps as follows: context analysis, input and planning, process, monitoring (outputs and outcomes) and adaptation.

Can Vegetation Removal Successfully Restore Coastal Dune Biodiversity?

Coastal dune habitats have been declining globally over the last several decades due to rapid urbanization. Within remaining dune systems, dune fixation has resulted in further losses of mobile dunes with negative impacts on their associated species. Some studies suggest vegetation removal can initially promote habitat heterogeneity, and increase availability of suitable habitats for psammophile, xeric and endemic mobile dune species, but longer-term responses are generally unknown. We investigated the temporal trends of four taxonomic groups to determine the effect of vegetation removal on dune assemblages over a 12-year period at an LTER site. Three different forms of removal are investigated here—removal in a grid form on fixed dunes, removal of the wind-facing slope vegetation on semi-fixed dunes and opportunistic off-road driving on disturbed dunes. Results were varied across taxa, highlighting the need for multi-taxa monitoring in conservation and restoration management. Overall, fixed dune treatment had very little effect, while a stronger response was found in semi-fixed treatments in particular for mobile dune indicator species, which showed evidence of recolonization within a few years following treatment. Disturbed dunes were most similar to mobile dunes for animal taxa indicating that pulse removal may not be as effective as continuous press disturbance. Nevertheless, a less destructive form of disturbance such as re-introduction of grazing might be preferable and requires further investigation.

Deer do not affect short-term rates of vegetation recovery in overwash fans on Fire Island after Hurricane Sandy

Coastal resilience is threatened as storm-induced disturbances become more frequent and intense with anticipated changes in regional climate. After severe storms, rapid recovery of vegetation, especially that of dune-stabilizing plants, is a fundamental property of coastal resilience. Herbivores may affect resilience by foraging and trampling in disturbed areas. Consequently, assessing the impacts of herbivores on recovering vegetation is important for coastal land management.We combined imagery classification, wildlife monitoring, and trend analysis to investigate effects of white-tailed deer on recovery rates of vegetation four years poststorm in nine overwashed areas. We estimated local deer density with trail cameras, how it relates to an index of primary productivity, and assessed the relationship between deer density and rates of vegetation recovery in overwash fans.Prestorm vegetation cover consisted of shrubs and sporadic patches of beach grass. Poststorm cover was dominated by beach grass. At current rates, vegetation coverage will return to prestorm conditions within the decade, though community transition from grasses to shrubs will take much longer and will vary by site with dune formation.The effect of deer on rates of vegetation recovery was negative, but not statistically significant nor biologically compelling. Although effects of deer trampling on beach grass are evident in classified imagery, deer foraging on beach grass had little effect on its rate of spread throughout overwash fans.While the rate of spread of the primary dune-building grass was not deleteriously affected by deer, locally high deer densities will likely affect the future establishment and development of herbs and shrubs, which are generally more palatable to deer than beach grass.

Effects of white-tailed deer (Odocoileus virginianus) exclusion on plant recovery in overwash fans after a severe coastal storm

We documented the impacts of an abundant deer population on dune vegetation recovering from severe storm surge on a barrier island through use of permanent plots and a repeated measures analysis. Three years after landfall of the storm, vegetation cover was dominated by American beachgrass, Ammophila breviligulata, though we observed 12 plant species among plots surveyed. We documented significantly greater vegetation cover in fenced than unfenced plots in overwash fans in two consecutive years. The difference in species richness between fenced and unfenced plots was significant, though richness was consistently low (≤4 species per plot) and we did not detect a statistically significant difference between years. Both deer trampling and foraging effects were captured in this study, though separation between these effects was not possible. Because trampling effects are often exacerbated on sandy soils, trampling and foraging effects should be isolated and investigated in future assessments of deer impacts on coastal vegetation. Managing deer to lower abundance may enhance coastal resilience if vegetation is allowed to recover unimpeded by foraging and trampling, though a better understanding of the precise nature of deer impacts on dune vegetation is necessary.

Is vegetation an indicator for evaluating the impact of tourism on the conservation status of Mediterranean coastal dunes?

Mediterranean coastal dunes are threatened by several factors; particularly, tourism causes modifications to the vegetation and the disappearance of endemic species. Understanding the dunes' conservation status is crucial for preserving these vulnerable environments through appropriate management strategies. This study was conducted on 17 Sardinian coastal dunes, with different levels of touristic pressure. We focused on endemic plant species and developed a new endemicity index (EI). Our study aimed: 1) to assess the conservation status by applying the diversity indices; 2) to verify if the study sites would reveal a general pattern based on different degrees of human disturbance and 3) to test the effectiveness of the EI index. Four m² plots (2 × 2 m) were placed along orthogonal transects to the coastline (446 plots in total), in which all plant species were identified, and their relative abundance was estimated. We found significant differences among the sites for H_dune and EI values but no statistically significant differences in the N values. The EI showed the high naturalistic value of Sardinian coastal dunes and allowed us to distinguish the sites with higher anthropic pressure. We found significant differences in the indices among the degrees of human disturbance in the coastal systems. The H_dune values were positively related to a medium level of human disturbance, and the EI allowed us to distinguish the sites with varying levels of human disturbance, although it differentiated better those with the highest anthropic pressure. A medium level of human disturbance was positively related to the plant richness and cover, and human trampling could be tolerated by psammophilous vascular plants. Results showed a satisfactory conservation status of Sardinian dune systems and highlighted diversity indices as valuable support for implementing a conservation strategy, compatible with the tourism purposes and the integrated management of the Mediterranean coastal dune systems.

Capturing Coastal Dune Natural Vegetation Types Using a Phenology-Based Mapping Approach: The Potential of Sentinel-2

Coastal areas harbor the most threatened ecosystems on Earth, and cost-effective ways to monitor and protect them are urgently needed, but they represent a challenge for habitat mapping and multi-temporal observations. The availability of open access, remotely sensed data with increasing spatial and spectral resolution is promising in this context. Thus, in a sector of the Mediterranean coast (Lazio region, Italy), we tested the strength of a phenology-based vegetation mapping approach and statistically compared results with previous studies, making use of open source products across all the processing chain. We identified five accurate land cover classes in three hierarchical levels, with good values of agreement with previous studies for the first and the second hierarchical level. The implemented procedure resulted as being effective for mapping a highly fragmented coastal dune system. This is encouraging to take advantage of the earth observation through remote sensing technology in an open source perspective, even at the fine scale of highly fragmented sand dunes landscapes.

Not just a sandy beach. The multi-service value of Mediterranean coastal dunes

Coastal sand dunes are complex transitional systems hosting high levels of biodiversity and providing important benefits to society. In this paper we aimed to evaluate the multi-service nature of ecosystem services (ES) supply in the dunes of the Italian Adriatic coast within Natura 2000 (N2K) sites. We i) identified ES indicators and assessed the supply capacity (Climate regulation, Protection from wind and aerosol, Erosion regulation, Recreation and Tourism and Existence value of biodiversity) of natural dune ecosystems of European conservation concern; ii) upscaled this data to create an inventory of ES supply for all dune N2K sites in the study area; iii) explored the trade-offs among ES; and iv) summarized and spatially compared the overall multi-service value of the N2K sites. The study provides a method for quantifying the role of N2K sites in supplying benefits for our society. We found that the multi-service capacity of coastal dunes is uneven within sites and within administrative regions. This variability is related to both ecological (e.g. distribution, ecological integrity, extent and conservation status of dune habitats) and administrative (e.g. local implementation of the Habitats Directive) characteristics of the analysed area. ES are not coupled as several sites with high values for one ES show very low values for others. The results suggest that conservation actions should favour restoration of the natural dune zonation, since this underpins multi-service ES supply. The approach can distinguish regions with high ES values and regions where the paucity of protected areas represents a gap in ES supply, fact that offers an incentive to enhance the protection strategy but also suggests an urgent need to improve the N2K network by enlarging existent sites and including new ones.

Multiple drivers of plant diversity in coastal dunes: A Mediterranean experience

In light of the global biodiversity loss, syntheses of the available knowledge about drivers of biodiversity are becoming increasingly important. However, despite the high number of studies analyzing patterns of plant species diversity, few attempts have been made to synthesize findings within different ecosystems. In this work, the relative role of a wide set of predictors imputable to three conceptual-methodological domains (abiotic, human-mediated disturbance and landscape domain, hereafter AD, DD and LD) was simultaneously analyzed in 644 random plots distributed along the coastal dunes of Central Italy. Native species richness and focal species cover, both field-recorded, were used as response variables. Predictors pertaining to the three domains were derived from both field surveys and high-resolution remotely sensed imagery (LiDAR and orthophotos). To test how AD, DD and LD affect native species richness and focal species cover, a GLM and a linear model were fitted respectively. The three domains were then ranked according to their relative importance. Although the role of the three domains was always significant, they turned out to unequally contribute to the explanation of native species richness and focal species cover patterns. For Mediterranean coastal dune ecosystems, AD appears to be the key biodiversity driver, followed by DD and LD. Our results suggest that as long as human disturbance is limited, plant diversity will distribute according to species abiotic tolerances, regardless of habitat loss and fragmentation per se. Representing a first effort towards a synthesis of plant diversity drivers in coastal dunes, this work points to the importance, in Mediterranean coastal dune ecosystems, of zonation dynamics, whose occurrence should be addressed as a priority issue by efficient conservations strategies.

Fishing lines and fish hooks as neglected marine litter: first data on chemical composition, densities, and biological entrapment from a Mediterranean beach

We reported first data on the densities and chemical composition of fishing lines and fish hooks deposited on a Mediterranean beach. On a sampling area of 1.5 ha, we removed a total of 185,028 cm of fishing lines (density 12.34 cm/m²) and 33 hooks (density 22 units/ha). Totally, 637.62 g (42.5 mg/m²) of fishing lines were collected. We sampled 120 items entangled belongings to 7 animal taxa (density 6.49 items/100 m of fishing lines). We also observed a not quantifiable number of egagropiles (Posidonia oceanica spheroids), Rhodophyceae (Halymenia sp.) and segments of reeds of Phragmites communis, trapped in the fishing lines. Fourier transform infrared (FTIR) spectroscopy was used in order to identify the chemical composition of the fishing lines: 92% was made of nylon while 8.0% was determined as fluorocarbon based polymers (polyvinylidene fluoride). Because of their subtlety and reduced size, sandy beach cleaning operations should include at least two consecutive removal samplings: indeed, a part of this litter (12.14%) is not removed in the first sampling. The unexpected high density of fishing lines suggests specific management actions aimed to periodically remove this neglected anthropogenic litter.

Tracking Fine-Scale Structural Changes in Coastal Dune Morphology Using Kite Aerial Photography and Uncertainty-Assessed Structure-from-Motion Photogrammetry

Coastal dunes are globally-distributed dynamic ecosystems that occur at the land-sea interface. They are sensitive to disturbance both from natural forces and anthropogenic stressors, and therefore require regular monitoring to track changes in their form and function ultimately informing management decisions. Existing techniques employing satellite or airborne data lack the temporal or spatial resolution to resolve fine-scale changes in these environments, both temporally and spatially whilst fine-scale in-situ monitoring (e.g., terrestrial laser scanning) can be costly and is therefore confined to relatively small areas. The rise of proximal sensing-based Structure-from-Motion Multi-View Stereo (SfM-MVS) photogrammetric techniques for land surface surveying offers an alternative, scale-appropriate method for spatially distributed surveying of dune systems. Here we present the results of an inter- and intra-annual experiment which utilised a low-cost and highly portable kite aerial photography (KAP) and SfM-MVS workflow to track sub-decimetre spatial scale changes in dune morphology over timescales of between 3 and 12 months. We also compare KAP and drone surveys undertaken at near-coincident times of the same dune system to test the KAP reproducibility. Using a Monte Carlo based change detection approach (Multiscale Model to Model Cloud Comparison (M3C2)) which quantifies and accounts for survey uncertainty, we show that the KAP-based survey technique, whilst exhibiting higher x, y, z uncertainties than the equivalent drone methodology, is capable of delivering data describing dune system topographical change. Significant change (according to M3C2); both positive (accretion) and negative (erosion) was detected across 3, 6 and 12 months timescales with the majority of change detected below 500 mm. Significant topographic changes as small as ~20 mm were detected between surveys. We demonstrate that portable, low-cost consumer-grade KAP survey techniques, which have been employed for decades for hobbyist aerial photography, can now deliver science-grade data, and we argue that kites are well-suited to coastal survey where winds and sediment might otherwise impede surveys by other proximal sensing platforms, such as drones.

Plastisphere in action: evidence for an interaction between expanded polystyrene and dunal plants

Among the many threats that can be recorded on sandy beaches, plastic litter represents a serious problem for these complex and endangered ecosystems. Expanded polystyrene (EPS) is increasingly abundant as a form of plastic litter in natural environments, particularly along shores and waterways. Nevertheless, despite the great number of scientific articles concerning the impact of litter on animal species, there are still no research focusing on the interaction between this type of beach litter and other biodiversity components. In this work, we reported the first evidence of interactions between EPS and living plants along a sandy beach of Tyrrhenian central Italy. We sampled 540 EPS items, mainly deriving from fishery activities (>75%). We obtained evidence for an interaction between EPS and plants: about 5% of items resulted perforated or have roots of three species (Phragmites australis, Spartina versicolor, Anthemis maritima). Apparently, we did not observed a relationship between plants and EPS items size. More research is needed to assess if the plant assemblage growing on EPS is random or if peculiar substrate exerts some sort of selection on the plant community.

The use of plant community attributes to detect habitat quality in coastal environments

The monitoring of biodiversity has mainly focused on the species level. However, researchers and land managers are making increasing use of complementary assessment tools that address higher levels of biological organization, i.e. communities, habitats and ecosystems. Recently, a variety of frameworks have been proposed for assessing the conservation status of communities or ecosystems. Among the various criteria proposed, all the protocols suggest considering (i) spatial aspects (range and area), and (ii) qualitative aspects of specific structures and functions. However, changes to ecological function are difficult to quantify and many protocols end up by using qualitative criteria. The aim of this work was to test the efficacy of some plant community attributes for the detection of vegetation quality in sand dune plant communities. We chose plant community attributes that either help to distinguish a habitat from others (diagnostic components) or play a significant role in habitat function and persistence over time. We used a diachronic approach by contrasting up-to-date vegetation data with data from previous studies carried out within the same areas. Changes in species composition were detected through detrended correspondence analyses (detrended correspondence analyses), Multi-Response Permutation Procedures and Indicator Species Analysis, while structural changes were analyzed by comparing species richness, total species cover, ecological groups of species and growth forms through null models. Ecological groups such as native focal species and aliens, and growth forms proved their efficacy in discriminating between habitat types and in describing their changes over time. The approach used in this study may provide an instrument for the assessment of plant community quality that can be applied to other coastal ecosystems.

Bats in a Mediterranean Mountainous Landscape: Does Wind Farm Repowering Induce Changes at Assemblage and Species Level?

We reported data on flying bat assemblages in a Mediterranean mountain landscape of central Italy on a 5-year time span (2005-2010) where a wind farm repowering has been carried out (from 2009, 17 three-blade turbines substituted an a priori set of one-blade turbines). In 4 yearly based surveys, we calculated a set of univariate metrics at species and assemblage level and also performing a diversity/dominance analysis (k-dominance plots) to evaluate temporal changes. Nine species of bats were present (eight classified at species level, one at genus level). Number of detected taxa, Margalef richness, and Shannon-Wiener diversity apparently decreased between 2005-2007 (one-blade turbine period) and 2009-2010 (three-blade turbines period). We showed a weak temporal turnover only between 2007 and 2009. In k-dominance plots, the occurrence curves of the years before the new wind farming activity (2005 and 2007) were lower when compared to the curves related to the 2009 and 2010 years, suggesting an apparent stress at assemblage level in the second period (2009 and 2010). Myotis emarginatus and Pipistrellus pipistrellus significantly changed their relative frequency during the three-blade wind farming activity, supporting the hypothesis that some bats may be sensitive to repowering. Further research is necessary to confirm a possible sensitivity also for locally rare bats (Miniopterus schreibersii and Plecotus sp.).

Mediterranean coastal sand dune vegetation: influence of natural and anthropogenic factors

The aim of the present work was to assess the conservation status of coastal dune systems in Tuscany (Italy). Emphasis was given to the presence and abundance of plant communities identified as habitat in accordance with the Directive 92/43/EEC. Twenty transects perpendicular to the shoreline were randomly positioned on the whole coastal area (30 km in length) in order to sample the full spectrum of plant communities. Vegetation zonation and relationships with the most frequent disturbance factors in the study area-beach cleaning, coastline erosion, presence of paths and roads, bathing settlements and trampling-were investigated through principal coordinate analysis and canonical correspondence analysis. Natural factors, such as distance from the sea and total length, were also considered. Differences in the conservation status of the sites were found, ranging from the total disappearance of the foredune habitats to the presence of the complete psammophilous (sand-loving) plant communities. Erosion, trampling, and paths were found to be closely correlated with degradation and habitat loss. Furthermore, the overall plant species diversity of dunes was measured with NHDune, a modified version of the Shannon index; while the incidence of invasive taxa was calculated using N, a naturalness index. However, these diversity indices proved to be a weaker bioindicator of ecosystem integrity than habitat composition along transects. A possible strategy for the conservation and management of these coastal areas could be to protect the foredunes from erosion and limit trampling through the installation of footbridges or the use of appropriate fences.

The fate of threatened coastal dune habitats in Italy under climate change scenarios

Coastal dunes worldwide harbor threatened habitats characterized by high diversity in terms of plant communities. In Italy, recent assessments have highlighted the insufficient state of conservation of these habitats as defined by the EU Habitats Directive. The effects of predicted climate change could have dramatic consequences for coastal environments in the near future. An assessment of the efficacy of protection measures under climate change is thus a priority. Here, we have developed environmental envelope models for the most widespread dune habitats in Italy, following two complementary approaches: an "indirect" plant-species-based one and a simple "direct" one. We analyzed how habitats distribution will be altered under the effects of two climate change scenarios and evaluated if the current Italian network of protected areas will be effective in the future after distribution shifts. While modeling dune habitats with the "direct" approach was unsatisfactory, "indirect" models had a good predictive performance, highlighting the importance of using species' responses to climate change for modeling these habitats. The results showed that habitats closer to the sea may even increase their geographical distribution in the near future. The transition dune habitat is projected to remain stable, although mobile and fixed dune habitats are projected to lose most of their actual geographical distribution, the latter being more sensitive to climate change effects. Gap analysis highlighted that the habitats' distribution is currently adequately covered by protected areas, achieving the conservation target. However, according to predictions, protection level for mobile and fixed dune habitats is predicted to drop drastically under the climate change scenarios which we examined. Our results provide useful insights for setting management priorities and better addressing conservation efforts to preserve these threatened habitats in future.

Integrating movement ecology with biodiversity research - exploring new avenues to address spatiotemporal biodiversity dynamics

Movement of organisms is one of the key mechanisms shaping biodiversity, e.g. the distribution of genes, individuals and species in space and time. Recent technological and conceptual advances have improved our ability to assess the causes and consequences of individual movement, and led to the emergence of the new field of 'movement ecology'. Here, we outline how movement ecology can contribute to the broad field of biodiversity research, i.e. the study of processes and patterns of life among and across different scales, from genes to ecosystems, and we propose a conceptual framework linking these hitherto largely separated fields of research. Our framework builds on the concept of movement ecology for individuals, and demonstrates its importance for linking individual organismal movement with biodiversity. First, organismal movements can provide 'mobile links' between habitats or ecosystems, thereby connecting resources, genes, and processes among otherwise separate locations. Understanding these mobile links and their impact on biodiversity will be facilitated by movement ecology, because mobile links can be created by different modes of movement (i.e., foraging, dispersal, migration) that relate to different spatiotemporal scales and have differential effects on biodiversity. Second, organismal movements can also mediate coexistence in communities, through 'equalizing' and 'stabilizing' mechanisms. This novel integrated framework provides a conceptual starting point for a better understanding of biodiversity dynamics in light of individual movement and space-use behavior across spatiotemporal scales. By illustrating this framework with examples, we argue that the integration of movement ecology and biodiversity research will also enhance our ability to conserve diversity at the genetic, species, and ecosystem levels.