Temperate temporary waterbody

This habitat type includes temporary freshwaters in the European temperate region. The associated plant communities seem not to be significant in the definition of the habitat which is mainly determined by hydrogeological and geomorphological conditions rather than by the biological component. These water bodies are characterized by large fluctuations of water level, which is related to the level of the underlying water table and to the amount of precipitation. In parts of the year, water is absent from these habitats and the plant and animal communities are mainly dependent by the seasonal hydrological regime, especially by the speed of drying out. The habitat can include a wide range of vegetation types, from wetland ones characterizing the areas where the water remains longer, to terrestrial ones in those areas where the water remains for a shorter time. The habitat includes the following distinct sub-types:

Turloughs have been described first as a habitat unique to Ireland but with a location also in Scotland and maybe Wales. However considering that this habitat is mainly determined by hydrological and geomorphological conditions it was recently recognized also in the Slovenian karst and other karstic areas of the temperate Europe and Mediterranean calcareous mountains. Turloughs are depressions of variable size developing on limestone, supporting vegetation and soils indicative of the prevalence of flooded conditions over at least part of the year. Flooding occurs annually in autumn mainly through springs and fissures in the underlying limestone though direct rainfall can have a secondary effect. Some turloughs in Ireland are affected by the tidal movements of coastal waters. In spring or summer draining often occurs through the same fissures or swallow-holes. Some turloughs can flood at any time within a few hours after heavy rainfall and subsequently may dry up again a few days later. This makes this habitat rather dynamic. The vegetation includes a range of vegetation alliances depending on flooding patterns, geomorphology, trophic status, grazing and climatic conditions. Mostly turloughs are grass- or sedge-dominated basins, which sometimes have a marsh or occasionally a permanent pond in the most depressed point. In the Burren, the high-water mark is often shown by Potentilla fruticosa. In Ireland the presence of the black moss Cinclidotus fontinaloides is a regular indicator of the location of a turlough. Moreover the habitat can includes rare wetland species such as the fen violet Viola persicifolia, the annual northern yellowcress Rorippa islandica and Callitriche palustris. In the Slovenian and Southern European karst systems, due to the different climatic and hydrological regimes, turloughs host mainly wet meadows. In these communities species such as Lotus corniculatus, Centaurea jacea, Galium verum, Ranunculus acris, R. repens, Agrostis stolonifera, Achillea millefolium are common. Turlough wetland communities can be classified into three main phytosociological classes: the Scheuzerio palustris-Caricetea fuscae of small-sedge communities, the Molinio-Arrhenatheretea including wet meadows and disturbed habitat communities, and the Littorelletea uniflorae lakeshore communities found on the margins of more permanent water bodies within turloughs. Caricion davallianae and Potentillion anserinae are the phytosociological alliances listed in the Habitats Directive as characteristic of this habitat. Aquatic and marsh communities often occur in the lower parts of turlough basins.

Lakes of gypsum karst is a very rare habitat, that includes small lakes that have developed by springs or spring complexes of active gypsum karst areas. The underlying rock might be gypsum or limestone, characterized by calcium sulphate and carbonate, respectively. Karst sinkholes might have a different shape and depth. They may appear as chains of funnel-shaped sinkholes and small hollows. They usually accumulate water but also fall dry periodically. The lakes are characterized by pronounced fluctuations of water level as well as high concentrations of calcium sulphate. Since lakes of gypsum karst significantly differ in shape, size, age and origin, their vegetation can be quite diverse. Older sinkholes can develop in lakes or bogs or into a terrestrial wet meadows vegetation. Younger ones can have a diverse vegetation including submerged and free-floating aquatic macrophytes. In general the vegetation is well adapted to fluctuating water levels (including semi-permanent conditions) and relatively high sulphate levels. Therefore, a number of alliances of the Littorelletea might be found in these habitats: Subularion aquaticae, Deschampsion litoralis, Lobelion dortmannae, Littorellion uniflorae, Hyperico elodis-Sparganion.

Indicators of good quality:

• The periodical alternation of wet-and-dry regimes
• The absence of heavy anthropogenic activities that can alter the hydrogeological system (e.g. water capitation and drainage)
• The absence of communities and species indicating an excessive nitrification or disturbance such as ruderal and exotic species

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats