Quels objectifs de restauration pour un ancien polder de la basse vallée du Vistre ?

In areas deeply modified by human activities, the target ecosystems for restoration and/or rehabilitation projects can seldom be related to known reference systems accepted by all parties. Such projects are hence constructed around objectives defined with the owner according to a combination of biological, hydrological, social and political criteria. The rehabilitation on the Vistre marshes (Gard, France) was in such a way orientated by multiple objectives. The change of the fallow land towards a wetland with floodplain functions, a regional patrimonial value, can be considered a success. The area is dry by the end of summer and is filled annually by autumn floods. lt supports fish communities that attract fish eating birds. The colony of tree nesting herons is one of the most important of the region, and hosts a significant proportion of the French population of Squacco Heron (Ardeola ralloides). Moreover, it was turned into a Nature Reserve before the end of the project. However, a detailed analysis leads to a more critical evaluation of the multi-objective choice done initially. It led to abundant and costly monitoring studies that did not necessarily provide useful answers. It was for example not possible to conclude to what extent the area was a sink for nutrients. The need for social and economic studies was under-evaluated despite objectives of human use (hunting, grazing and reed harvesting). lt was concluded that such a project should be more strictly aimed to few targets, monitored and evaluated rigorously. Additional biological, hydrological, economical or social issues, in that case would be taken into account only when compatible with the priority objectives set. The initial choices have to be defined carefully and agreed upon by ali stakeholdersDans des zones fortement modifiées par les activités humaines, les systèmes visés par des projets de restauration et/ou de réhabilitation ne peuvent que rarement être définis par rapport à des écosystèmes de référence connus et acceptés par tous. Les projets sont donc construits autour d'objectifs déterminés avec les commanditaires selon des critères biologiques, hydrologiques, sociaux et politiques. La réhabilitation de marais dans la basse vallée du Vistre (Gard, France) a ainsi été orientée par de multiples objectifs. Le retour d'une friche agricole à une zone humide qui assure son rôle de plaine d'inondation, et qui a une valeur patrimoniale régionale, peut être considéré comme un succès. La colonie de hérons arboricoles y est une des plus importantes de la région et abrite une proportion significative de la population française de Héron crabier (Ardeola ralloides). L'analyse détaillée des divers aspects amène cependant à une évaluation plus critique du caractère multi-objectifs du projet qui a conduit à de nombreux suivis dont certains n'ont pas répondu aux questions posées. Il n'a pas été possible par exemple de conclure sur le caractère source ou puits pour les nutriments. L'importance des études sociales et économiques, malgré des objectifs d'usage, n'a pas été assez prise en compte. Nous concluons qu'un tel projet doit être centré sur peu d'objectifs, suivis et évalués avec rigueur, et qui auront été l'objet d'un consensus initial. Les autres demandes, biologiques, hydrologiques, économiques ou sociales, des acteurs et/ou commanditaires, ne seront prises en compte que si elles sont compatibles avec ces objectifs prioritaires et serviront surtout à définir les limites d'interventio

The Plants of Mediterranean temporary pools: do we know enough for their conservation?

Mediterranean wetlands combine high conservation value and intense pressure from human activities and climate change. Temporary pools, which are important habitats for biodiversity in the Mediterranean region, are particularly exposed to destruction following their small size and depth. They show high species richness including many rare and specialized species, as well as high beta and gamma diversity resulting from the range of environmental conditions they encompass

Bellis prostrata Pomel (Asteraceae), a new species for Morocco

Investigations conducted in temporary wetlands of the coastal Meseta of W Morocco (Benslimane region) lead to the discovery of Bellis prostrata in a small endoreic temporary pool (ca. 1 ha) of the quartzitic-limestone plateau of Benslimane

6. Peatland Conservation

Expert assessors Stephanie Boudreau, Canadian Sphagnum Peat Moss Association, Canada Emma Goodyer, IUCN UK Peatlands Programme, UK Laura Graham, Borneo Orangutan Survival Foundation, Indonesia Richard Lindsay, University of East London, UK Edgar Karofeld, University of Tartu, Estonia David Locky, MacEwan University, Canada Nancy Ockendon, University of Cambridge, UK Anabel Rial, Independent Consultant & IUCN Species Survival Commission, Colombia Sarah Ross, Penny Anderson Associates, UK Nigel..

Seventeen ‘extinct’ plant species back to conservation attention in Europe

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.info:eu-repo/semantics/publishedVersio

Ramsar Wetlands of International Importance–improving conservation outcomes

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 km2, 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

Network‐scale effects of invasive species on spatially‐structured amphibian populations

Understanding the factors affecting the dynamics of spatially‐structured populations (SSP) is a central topic of conservation and landscape ecology. Invasive alien species are increasingly important drivers of the dynamics of native species. However, the impacts of invasives are often assessed at the patch scale, while their effects on SSP dynamics are rarely considered. We used long‐term abundance data to test whether the impact of invasive crayfish on subpopulations can also affect the whole SSP dynamics, through their influence on source populations. From 2010 to 2018, we surveyed a network of 58 ponds and recorded the abundance of Italian agile frog clutches, the occurrence of an invasive crayfish, and environmental features. Using Bayesian hierarchical models, we assessed relationhips between frog abundance in ponds and a) environmental features; b) connectivity within the SSP; c) occurrence of invasive species at both the patch‐ and the SSP‐levels. If spatial relationships between ponds were overlooked, we did not detect effects of crayfish presence on frog abundance or trends. When we jointly considered habitat, subpopulation and SSP features, processes acting at all these levels affected frog abundance. At the subpopulation scale, frog abundance in a year was related to habitat features, but was unrelated to crayfish occurrence at that site during the previous year. However, when we considered the SSP level, we found a strong negative relationship between frog abundance in a given site and crayfish frequency in surrounding wetlands during the previous year. Hence, SSP‐level analyses can identify effects that would remain unnoticed when focussing on single patches. Invasive species can affect population dynamics even in not invaded patches, through the degradation of subpopulation networks. Patch‐scale assessments of the impact of invasive species can thus be insufficient: predicting the long‐term interplay between invasive and native populations requires landscape‐level approaches accounting for the complexity of spatial interactions

Puntos de inflexión en los gradientes de composición de las comunidades de plantas acuáticas de diferentes continentes

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.publishedVersio