Global projections indicate that between 20% and 90% of current coastal wetland areas may be lost due to sea-level rise (SLR), depending on the severity of the scenario. Warming, acidification and other global change stressors such as eutrophication also show negative impacts on coastal wetlands. Such a scenario poses a dramatic threat to biodiversity, particularly in deltas and estuaries, which are vital for the conservation of coastal species and ecosystem functions. This paper summarizes the main impacts of climate change on coastal wetland biodiversity, with focus on vegetation, birds and fish. Management options to cope with climate change impacts are also summarized. Many coastal wetlands are already undergoing degradation or disappearing due to the combined impacts of climate change and other global drivers, including SLR, subsidence, sediment deficits, coastal erosion, and salt stress. Coastal squeeze, the restriction of natural habitat migration due to human infrastructure and natural constraints, also threatens these ecosystems. Enhancing the resilience of coastal wetlands involves improving hydrological connectivity, increasing sediment inputs, boosting wetland plant productivity, and allowing space for natural coastal processes. However, these efforts are highly dependent on active conservation, management and restoration policies. The future of coastal wetland biodiversity will vary significantly based on the climate scenarios that unfold, and the policies implemented. Highlights Coastal wetland biodiversity has severely declined due to habitat loss and other aspects of global change. Remaining wetlands are endangered by climate change impacts such as sea level rise.Salt marshes are the most endangered coastal wetlands in Europe, along with their associated flora and fauna. The Mediterranean coast may lose up to 90% of those habitats by the end of the 21st century due to sea level rise.Boosting coastal wetland resilience is critical to avoid biodiversity loss. To do this requires increasing the pace and scale of coastal wetland restoration, and enhancing the ecogeomorphic dynamics through the increase of hydrological connectivity and the supply of sediments to the coasts.

Temporary ponds are vital ecosystems in the Mediterranean basin, supporting many specialized species. Plants must endure significant interannual fluctuations in pond hydrology and may face increased stress from climate change. While research has largely focused on community-level dynamics, we still lack a clear understanding of how species respond to hydrology and the relative roles of plasticity versus adaptation in their responses. We studied selected vegetative (height, number of leaves, leaf area) and reproductive (number of fruits, number of seeds/spores per fruit, number of seeds/spores per plant, seed/spore size and seed mass) traits of six characteristic species (of the genera; Baldellia, Damasonium, Elatine and Isoetes) in 20 temporary ponds along a 750 km north-south latitudinal (climate) gradient (31 degrees-35 degrees N) in Morocco (mean annual precipitation range 264 to 856 mm). Traits were assessed on both field-collected specimens and those grown from seeds/spores in mesocosms under uniform experimental conditions. Our results showed a significant correlation between latitude and plant traits in the field. From north (humid) to south (dry), plants became shorter, with fewer and smaller leaves, fewer fruits, smaller seeds/spores, lower mass per fruit/sporangium, and fewer seeds per plant. Reduced growth and fecundity along the gradient likely result from limited and variable flooding in the south, increasing plant stress. However, these differences in traits were not observed when the plants were grown under common garden conditions. This pattern strongly suggests that differences in plant traits across the six species are mainly due to phenotypic plasticity to local hydrological conditions, although potential genetic differentiation cannot be excluded. In conclusion, phenotypic plasticity, likely favored by large interannual variations in hydrological conditions, may enhance species resilience to climate change and may aid in population transfers for restoration projects.

The role of temporary ponds in carbon budgets remains poorly understood, particularly in arid regions. This study quantified soil organic carbon (SOC) stocks in 15 temporary ponds in Morocco, across three land use types (agricultural, reserve, forest). In each pond, one soil core was collected in each of the three topographic zone (peripheral, intermediate, and central) and divided in three soil depth (0–15, 15–30, 30–45 cm) with sub-samples (3) averaged by layer. Relationship with vegetation abundance and plant diversity (aquatic and terrestrial), hydrological and soil properties were also assessed. SOC content was measured, and factorial ANOVAs with Tukey’s tests were used for statistical analysis. SOC density was significantly higher in agricultural and reserve ponds than in forest ponds. Total SOC stock was positively correlated with hydrology, soil nutrients, and vegetation attributes, while topographic zone, soil depth, or their interaction showed no significant effects. Extrapolation to all 672 ponds in the 2760 km2 study area estimated a total SOC stock of 153,878 metric tons. These results highlight the importance of conserving agricultural ponds and creating new reserves in pond-rich forest areas to maximize carbon sequestration in semi-arid regions.

Introduction Temporary ponds in the Mediterranean climate have a high conservation value, but many have been severely destroyed or degraded. Pond restoration and new pond creation have been engaged widely. Evaluations of the success of such operations are generally carried out over 10-15 years and show divergent results over this timeframe. In the Camargue (Rh & ocirc;ne delta, South of France), several temporary ponds were created with various objectives since the second half of the 19th century.Objectives Study the long-term trajectory of plant communities in created temporary ponds and compare them with those of reference temporary ponds.Methods We carried out vegetation surveys and measured environmental parameters in 25 ponds created in the 19th, 20th, and 21st centuries, as well as in 27 natural reference ponds (space-for-time substitution approach).Results Submerged macrophyte communities (composition, abundance, and species-richness) converged toward the reference communities after one or several decades. Emergent plant communities (terrestrial plants and helophytes) converged more slowly toward the reference communities (composition and abundance). Even after 150 years, the emergent plant communities with the highest conservation interest (in particular Natura 2000 habitat) were not found in created ponds.Conclusions The creation of temporary ponds in the Camargue is of conservation interest but cannot compensate for the loss of natural temporary ponds.

Coastal wetlands host a large part of the world’s biodiversity and provide various ecosystem services with a known economic value. However, they experience many pressures due to anthropogenic and natural drivers, causing periodic changes in their structure and functioning. Earth Observation provides opportunities for monitoring water surface dynamics and understanding the impacts of different drivers on wetland degradation. This study had two objectives: to assess the spatiotemporal dynamic of the Sidi Boughaba Lake surface area (Mediterranean and North African coastal Ramsar site, Morocco) over 38 years (1984–2021) and to identify natural and anthropogenic drivers of this dynamic, mainly land-use and land-cover changes and policies. This work focused on the use of multiple datasets based on remote sensing images within a cloud-based computing platform. Time series of satellite images were classified and used after a series of processing procedures to assess the land use and land cover and water extent dynamics. Results reveal that over 38 years, the lake shows intra- and inter-annual variations, including significant losses of permanent water impacting its dynamic and extent. Those trends call into question the urban and agricultural policies adopted. Pressure on resources and the regressive trend recorded in the dynamic of the lake are likely to increase further in future years if effective protection measures are not implemented. The results of this study help authorities, civil society, and decision makers to make decisions and call for action to protect these areas and maintain their capacity to provide ecosystem services and address global concerns such as biodiversity conservation and climate change mitigation.

The concept of a reference ecosystem is fundamental in restoration ecology, especially in assessing the success of ecological restoration projects. In response to criticism, it has undergone conceptual evolutions in its definition and use in the last decades. Even though there is still a need to develop statistical methods and analyses to account for reference variability. Here, we focus on two original and one literature‐based calculation methods for designed indexes, which all aim to compare a community to be assessed (undergoing restoration) with a variable set of reference communities. These methods either use the average reference situation (species composition and abundance) as the restoration target or on the contrary, allow any reference site to be considered a relevant target. We compare the results of these methods by analyzing a simulated dataset. We then illustrate the application of the most relevant index by a real case study that compared a created Mediterranean temporary pond to a panel of 27 reference ponds located in the south of France. The results show that the Distance to Reference Communities Index (DRCI) correctly measures differences in species composition and abundance between an assessed and a reference panel of communities. It takes into account the variability of the reference communities, while the use of other indexes focuses on unrealistic average and fixed reference values. DRCI is complementary to a detailed ecological interpretation and to the use of other commonly used indexes, by giving a synthetic metric.

Coastal wetlands are crucial in climate change regulation due to their capacity to act as either sinks or sources of carbon, resulting from the balance between greenhouse gas (GHG) emissions, mainly methane (CH4), and soil carbon sequestration. Despite the paramount role of wetlands in climate regulation few studies investigate both aspects. The Camargue is one of the largest wetlands in Europe, yet the ways in which environmental and anthropic factors drive carbon dynamics remain poorly studied. We examined GHG emissions and soil organic carbon (SOC) stocks and accumulation rates in twelve representative wetlands, including two rice fields, to gain insights into the carbon dynamics and how it is influenced by hydrology and salinity. Mean CH4 rates ranged between - 87.0 and 131.0 mg m-2 h-1and the main drivers were water conductivity and redox, water table depth and soil temperature. High emission rates were restricted to freshwater conditions during summer flooding periods whereas they were low in wetlands subjected to summer drought and water conductivity higher than 10 mS cm-1. Nitrous oxide emissions were low, ranging from - 0.5 to 0.9 mg N2O m-2 h-1. The SOC stocks in the upper meter ranged from 17 to 90 Mg OC ha-1. Our research highlights the critical role of low-saline wetlands in carbon budgeting which potentially are large sources of CH4 but also contain the largest SOC stocks in the Camargue. Natural hydroperiods, involving summer drought, can maintain them as carbon sinks, but altered hydrology can transform them into sources. Artificial freshwater supply during summer leads to substantial CH4 emissions, offsetting their SOC accumulation rates. In conclusion, we advocate for readjusting the altered hydrology in marshes and for the search of management compromises to ensure the compatibility of economic and leisure activities with the preservation of the inherent climate-regulating capacity of coastal wetlands.

Unravelling patterns and mechanisms of biogeographical transitions is crucial if we are to understand compositional gradients at large spatial extents, but no studies have thus far examined breakpoints in community composition of freshwater plants across continents. Using a dataset of almost 500 observations of lake plant community composition from six continents, we examined, for the first time, if such breakpoints in geographical space exist for freshwater plants and how well a suite of ecological factors (including climatic and local environmental variables) can explain transitions in community composition from the subtropics to the poles. Our combination of multivariate regression tree (MRT) analysis and k-means partitioning suggests that the most abrupt breakpoint exists between temperate to boreal regions on the one hand and freshwater plant communities harbouring mainly subtropical or Mediterranean assemblages on the other. The spatially structured variation in current climatic conditions is the most likely candidate for controlling these latitudinal patterns, although one cannot rule out joint effects of eco-evolutionary constraints in the harsher high-latitude environments and post-glacial migration lags after Pleistocene Ice Ages. Overall, our study supports the foundations of global regionalisation for freshwater plants and anticipates further biogeographical research on freshwater plant communities once datasets have been harmonised for conducting large-scale spatial analyses.

This issue of Marine and Freshwater Research celebrates 50 years of the Ramsar Convention on Wetlands, which was signed in 1971. It contains papers that describe the development of the Convention and its implementation, including the listing of wetlands of international importance and maintenance of their ecological character. The latter is a fundamental issue for wetland management as illustrated in papers that address a range of management issues, including the impact of climate change, and approaches for building awareness about their values, and concludes with a forward view for potentially reframing human–wetland relationships.

Coastal lagoons have been recognised as a priority habitat for conservation and have benefited from several conservation plans. Under the Mediterranean climate, some of these lagoons might dry out during summer due to drought events. We propose the term Mediterranean Temporary Lagoons (MTLs) for these ephemeral water bodies and discuss their definition and characteristics. This term emerged in France among its coastal zone managers, who now commonly use it for conservation purposes. It is used in both natural systems as well as most artificial salt ponds in abandoned saltworks. In Europe, two directives have integrated lagoons as key targets to be preserved. Nonetheless, a certain discrepancy in the different definitions of lagoons has constrained joint actions. Indeed, while institutional definitions were originally derived from the scientific concept, their legislative and managerials meanings have been gradually modified and nowadays often differ from the original concept to create difficulties in the field. In addition, while it has been recommended to consider MTLs as a coastal lagoon habitat in the European Habitat Directive, its interpretation among EU member states is unsettled. Thus, clarifying lagoon habitats' terminology is required to ensure better management, monitoring and planning, and coordinate conservation actions. We discuss the inclusion of MTLs in habitat 1150 by confronting scientific and institutional literature and propose a new framework to better delimitate lagoon habitat around the Mediterranean basin, integrating MTLs. MTLs represent a specific habitat that hosts a pool of stenoecious macrophytes of conservation interest like Althenia filiformis, Riella helicophylla or Tolypella salina.

This article presents information on the distribution and ecology of Callitriche species in Morocco, based on field survey, literature review, and examination of herbarium specimens. Taxa reported erroneously from the country are discussed and new information is presented on the morphology of C. mathezii and C. truncata subsp. truncata.

15 Captive breeding, rearing and releases (ex situ conservation) 3.15.1 Captive breeding Artificially incubate and hand-rear birds in captivity (raptors) Artificially incubate and hand-rear birds in captivity (seabirds) Artificially incubate and hand-rear birds in captivity (songbirds) Artificially incubate and hand-rear birds in captivity (waders) Use captive breeding to increase or maintain populations (raptors) Artificially incubate and hand-rear birds in captivity (bustards) Artificially incubate and hand-rear birds in captivity (cranes) Artificially incubate and hand-rear birds in captivity (gamebirds) Artificially incubate and hand-rear birds in captivity (parrots) Artificially incubate and hand-rear birds in captivity (penguins) Artificially incubate and hand-rear birds in captivity (rails) Artificially incubate and hand-rear birds in captivity (storks and ibises)1.

Wetlands are critically important for biodiversity and human wellbeing, but face a range of challenges. This is especially true in the Mediterranean region, where wetlands support endemic and threatened species and remain integral to human societies, but have been severely degraded in recent decades. Here, in order to raise awareness of future challenges and opportunities for Mediterranean wetlands, and to inform proactive research and management, we identified (a) 50 key issues that might affect Mediterranean wetlands between 2020 and 2050, and (b) 50 important research questions that, if answered, would have the greatest impact on the conservation of Mediterranean wetlands between 2020 and 2050. We gathered ideas through an online survey and review of recent literature. A diverse assessment panel prioritised ideas through an iterative, anonymised, Delphi-like process of scoring, voting and discussion. The prioritised issues included some that are already well known but likely to have a large impact on Mediterranean wetlands in the next 30 years (e.g. the accumulation of dams and reservoirs, plastic pollution and weak governance), and some that are currently overlooked in the context of Mediterranean wetlands (e.g. increasing desalination capacity and development of antimicrobial resistance). Questions largely focused on how best to carry out conservation interventions, or understanding the impacts of threats to inform conservation decision-making. This analysis will support research, policy and practice related to environmental conservation and sustainable development in the Mediterranean, and provides a model for similar analyses elsewhere in the world.

ABSTRACT Wetlands have been declining worldwide, with an estimated 64–71% loss over the last century. Climate change is increasing pressure on wetlands, affecting their hydrology, and Mediterranean temporary ponds could be particularly vulnerable to these changes. We studied the expected changes in hydrology and plant community according to climatic change scenarios in 18 temporary ponds distributed in 6 areas along a latitudinal and climatic gradient in Morocco (750 km; 4° latitudinal gradient). Richness of pond species was significantly correlated with water level and pond hydroperiod and showed a strong decline from north to south along with increased water stress. Using the Mar-O-Sel software (mar-o-sel.net), we simulated the future evolution of water balance and wetland hydroperiod (duration and frequency of flooding) in these ponds for mid- and late-21st century. Climate projections were estimated based on 2 Representative Concentration Pathway (RCP) scenarios assuming a stabilization (RCP4.5) or increase (RCP8.5) in greenhouse gas emissions. The mean water deficit of the ponds currently ranges between −1380 and −1812 mm/yr and would increase by 16–67% in 2100 under the RCP8.5 scenarios. Pond richness is expected to decrease by 8–15 species in 2100, depending on area, as a result of shorter projected hydroperiods. Severity of change was not related to location of the ponds along the latitudinal (aridity) gradient, but rather to the interaction between the size of their catchment area and the thickness of the permeable soil layer.

Seventeen European endemic plant species were considered extinct, but improved taxonomic and distribution knowledge as well as ex situ collecting activities brought them out of the extinct status. These species have now been reported into a conservation framework that may promote legal protection and in situ and ex situ conservation.

The ecological niche defines the favourable range of a species in a multidimensional space of ecological factors that determine the presence and function of individuals. This fundamental concept in ecology is widely used to understand plant species coexistence and segregation. In this study, we test for ecological differentiation among six annual Lythrum species that are characteristic of temporary pools in the South of France, where they either coexist or occur separately. We first analysed the co-occurrence of species at two different geographical scales: cluster analyses of species presence in 10 km grid cells and coexistence in 0.25 m2 quadrats within populations of each species. Second, for three to nine populations of each species, we quantified a range of biotic and abiotic parameters using point contacts and soil measurements in five 0.25 m2 quadrats per population. We performed PCA on all variables and analysed each variable separately to compare the ecological niche features of the six species. A phenological index was assessed for the plant community of each site. We detected highly localized niche differentiation in terms of soil pH (all species) and for a range of variables among pairs of species. The six species also showed marked differences in the flowering period relative to the mean and variability of flowering time in their local community. These fine-scaled niche differences are associated with phylogenetic distances among species and may contribute to species' coexistence. These results are integrated in a conservation management plan for the habitat of the rarest species in this group.

The Andalusian International University held a workshop entitled Temporary wetlands' future in drylands under the projected global change scenario in March 2020 in Baeza, Spain, with 26 participants from 10 countries. The workshop objectives were to promote international cooperation and scientific exchange on the conservation and protection of temporary wetlands. The participants highlighted the extreme conditions that temporary and permanent wetlands, ponds, and shallow lakes are currently facing and predicted a dismal future for these systems due to climate change. To foster a holistic view of these ecosystems, the workshop included wetland watersheds. It was concluded that the main threats are those affecting water quality and quantity as well as egg-seed banks, species population dynamics, and food webs. The inherent characteristics of waterbodies in drylands, including high resilience and resistance to harsh conditions, are already negatively impacted by direct human actions and climate change. Another threat is the time lag between scientific warnings about threats and the social and political concern leading to mitigating actions. Thus, more effective actions to protect and conserve temporary wetlands are essential. Research networks could help stimulate the necessary conservation actions, but the global recession due to the COVID-19 pandemic will pose a challenge as economies are burdened with urgent expenditure. This special issue of the journal Inland Waters is the outcome of the workshop presentations and is composed of the ensuing papers on wetlands in drylands.

QuestionsWhich are the effects of inter-annual meteorological fluctuations on plant species richness and vegetation dynamics in Mediterranean temporary ponds, shallow wetlands characterized by alternating phases of drought and flooding? Which are the effects of wild boar disturbance? How do the responses of specialist or non-specialist species of the habitat differ? LocationNW Sardinia Island (Italy). MethodsWe assessed plant cover during six years within one 60 cm x 60 cm quadrat in each of five areas. To measure the effect of inter-annual meteorological fluctuations on vegetation, we used two indices: the evapotranspiration and the synthetic agrometeorological indicator. To quantify the effect of disturbance by boars, we compared two treatments: disturbed and non-disturbed (located outside and inside 1.5 m x 1.5 m exclosures respectively). As a whole, we monitored 60 plots (6 years x 2 treatments x 5 replications). We analyzed data using ANOVA, PERMANOVA and BIO-ENV. ResultsPlant species richness and composition showed significant differences between years and treatments. Species composition was correlated with the evapotranspiration before the vegetative peak during the last period and with the agrometeorological indicator during the whole vegetative period. Specialist species showed much weaker growth, quantified as cover, in the drier years. Starting from the third survey year, plant richness and cover of specialist species were significantly higher in disturbed than in not-disturbed plots. The extent of bare soil generally was not affected by the treatment. ConclusionsMeteorological fluctuations affect plant species composition and vegetation dynamics in Mediterranean temporary ponds. The sensitivity of specialist species could make them particularly vulnerable to climate change. Nevertheless, they are resilient to unpredictable disturbances such as burrowing by wild boar. However, our results concerning the positive impact of wild boar disturbance on the vegetation cannot be generalized. Elsewhere, the lack of hunting activity could also be a problem for these habitats.

The Ramsar Convention (or the Convention on Wetlands), signed in 1971, was one of the first international conservation agreements, promoting global wise use of wetlands. It has three primary objectives: national designation and management of wetlands of international importance; general wise use of wetlands; and international cooperation. We examined lessons learnt for improving wetland conservation after Ramsar’s nearly five decades of operation. The number of wetlands in the Ramsar Site Network has grown over time (2,391 Ramsar Sites, 2.5 million km 2 , as at 2020-06-09) but unevenly around the world, with decreasing rate of growth in recent decades. Ramsar Sites are concentrated in countries with a high Gross Domestic Product and human pressure (e.g., western Europe) but, in contrast, Ramsar Sites with the largest wetland extent are in central-west Africa and South America. We identified three key challenges for improving effectiveness of the Ramsar Site Network: increasing number of sites and wetland area, improved representation (functional, geographical and biological); and effective management and reporting. Increasing the number of sites and area in the Ramsar network could benefit from targets, implemented at national scales. Knowledge of representativeness is inadequate, requiring analyses of functional ecotypes, geographical and biological representativeness. Finally, most countries have inadequate management planning and reporting on the ecological character of their Ramsar Sites, requiring more focused attention on a vision and objectives, with regular reporting of key indicators to guide management. There are increasing opportunities to rigorously track ecological character, utilizing new tools and available indicators (e.g., remote sensing). It is critical that the world protect its wetlands, with an effective Ramsar Convention or the Convention on Wetlands at the core.