10. Gefährdung und Schutz von Characeen

This chapter describes the threats of charophytes and their habitats and specifies appropriate actions for theirconservation and protection. Main reasons for endangering are habitat destruction, water pollution, increase of utilization(e.g. water management, river regulation, disturbances by fishery, recreation activities), drainage, lack of management,rarity, climate change, introduction of foreign plants and inadequate legal protection. Following the latest Red Data Books81 % of the charophyte-species and 88 % of the charophyte-plant communities in Germany are threatened. An overview about thedegrees of endangering of charophytes in other European countries is presented additionally. The legal foundations forprotection of charophytes and their habitats in Germany are analysed with special emphasis to European directives (EuropeanHabitats Directive, European Water Framework Directive) and international conventions (e.g. Convention on BiologicalDiversity, Global Strategy for Plant Conservation). Different measures for conservation and protection of charophytes arediscussed. The most important aim is the protection of extant populations against damage and their prevention from nutrientloading. Because many charophytes are poor competitors most of their sites (especially small water bodies and ditches) needa special management as periodical remove of vegetation/mud and creation of vegetation-free areas. Other measures discussedare e.g. an improvement or re-establishment of natural dynamics, development of seminatural fish stocks, creation of newwaterbodies, implementation of buffer strips, improvement of legal protection and establishment of naturereserves. Alternative concepts (e.g. Important Stonewort Areas, Plant Micro-Reserves) must be verified, too. The continuousdecline of charophytes requires urgent measures to stop the loss of species and habitats. Therefore the implementation of avalid national action plan for protection and conservation of charophytes and their habitats in Germany focussing on themost endangered species is proposed. A subdivision into 5 action plans for 15 threatened charophytes is suggested. Inaddition local action plans must be realized for 6 species with present occurrence in less than five sites. The proposedactions aim especially at an improvement of knowledge of the present and former occurrence of the target species, theirecological demands, the identification of the present national hot spots for conservation of charophytes in Germany, thepromotion of public relations and the realization of management measures including transplantation of oospores.