No abstract

Highlights:-Plant communities in coastal wetlands are at risk due to the impacts of global change-Knowing the distribution of plant communities is essential for nature conservation-Communities distribution maps were produced using a UAV-based multispectral sensor-The Random Forest classifier yielded the highest classification accuracy-Species diversity and aboveground biomass affect the classification performance ABSTRACT Coastal meadows worldwide are subjected to habitat degradation due to abandonment, intensification and the impacts of global change. In order to protect and restore these habitats and ensure the supply of valuable ecosystem services, it is necessary to know the extent and location of plant communities in coastal meadows. In this study, five plant communities were mapped at very high resolution in three different study sites in West Estonia. A fixed wing UAV was used to obtain multispectral images and derive a set of vegetation indices. Two different image classification techniques were used to cluster the vegetation indices maps and produce plant community distribution maps. The highest classification accuracy was obtained using a Random Forest classifier and 13 vegetation indices. Additionally, the spectral characteristics of the training samples were correlated with aboveground biomass and species diversity. Both biomass and species diversity were positively correlated with the spectral diversity of training samples and are thus likely to have an effect on the classification accuracy. The results of this study highlight the need to utilize a wide array of vegetation indices and assess the spectral characteristics of training samples in order to obtain high classification accuracies and understand the nature of misclassification errors. The resulting maps provide a solid foundation for global change impact assessment and habitat management and restoration in coastal meadows.

Boreal Baltic coastal wetlands differ markedly from temperate salt marshes by their generally low maximum elevation (between 0 and 1 m above m.s.l.), low seaward gradients and the irregular nature of flooding that is characteristic of the NE Baltic Sea coastal region. As a result of these factors these wetlands have been considered to be threatened by future sea level rise. This study presents results for two Boreal Baltic coastal wetland sites in Estonia using The recent acceleration in the rate of global sea-level rise may subtly alter this relationship. However current rates of GIA and sedimentation will continue to maintain the progradation of Boreal Baltic coastal wetlands in the coming decades.

The red list has become a ubiquitous tool in the conservation of species. We analyzed contemporary trends in the threat levels of European orchids, in total 166 species characterized in 27 national red lists, in relation to their reproductive biology and growth form, distribution area, and land cover where they occur. We found that species in central Europe are more threatened than those in the northern, southern, or Atlantic parts of Europe, while species were least threatened in southern Europe. Nectarless and tuberous species are significantly more threatened than nectariferous and rhizomatous taxa. Land cover (ratios of artificial land cover, area of pastures and grasslands, forests and inland wetlands) also significantly impacted the threat level. A bigger share of artificial land cover increases threat, and a bigger share of pasture and grassland lowers it. Unexpectedly, a bigger share of inland wetland area in a country increased threat level, which we believe may be due to the threatened nature of wetlands themselves relative to other natural land cover types. Finally, species occurring in multiple countries are on average less threatened. We believe that large‐scale analysis of current IUCN national red lists as based on their specific categories and criteria may particularly inform the development of coordinated regional or larger‐scale management strategies. In this case, we advocate for a coordinated EU protection and restoration strategy particularly aimed at central European orchids and those occurring in wetland area.

No abstract