Volume XV |

Floristic composition and functional zones pattern of the beach-dune system along the Danube Delta coast – Romania

Abstract: This paper presents the floristic composition of vegetation for each feature on a beach-dune system sector from the western Black Sea coast, Romania. The studied site is a relatively small fragment of the 10 km shore on the southern part of the Danube Delta Biosphere Reserve (DDBR) that may be susceptible to anthropogenic pressure in the coming years. Out of the 38 identified species, ten are threatened species according to the national Red List of endangered plant species. Compositae and Poaceae are the families with the highest number of species. The analysis of floristic spectrum shows a mixture of elements of plant communities, but Pontic and Ponto-Caspian elements are prevalent.
Physiognomically, the foredunes in the Danube delta coast have a typical morphology, with a smooth profile and do not exceed 2 m high. They are vegetated by herbaceous annual and perennial plants, but in terms of abundance the native dune builder rhizomatous grasses are rare.
The fore dunes from this Black Sea coast sector serve as vital habitat and refuge for Convolvulus persicus L. within the western limit of its geographical range. This endemic Ponto-Caspian element defines a particular habitat type within the Black Sea biogeographic region: “Pontic shore dunes with Convolvulus persicus L.” Currently, the main threats of this habitat are cattle grazing and the increasing touristic activities (human trampling, horse riding and all-terrain vehicle riding).

Volume XIII |

Conservation Status and Conservation Strategies of threatened aquatic fern Marsilea quadrifolia L. in Europe

Abstract: The aquatic fern Marsilea quadrifolia L is a rare and threatened species in entire Europe due to wetland habitats destruction and changing agricultural practices. To protect it, in situ and ex situ conservation methods are approached in European Union an in other countries. The in vivo and in vitro collections that were developed in botanical gardens in the last two decades are used for reintroduction and for restoration of M. quadrifolia populations in natural sites as well as in agro ecosystems that are analogous to natural habitats. Natural establishment of several M. quadrifolia populations in its natural range is an evidence that it can colonize new suitable habitats, including anthropogenic habitats. Despite conservation strategies approached within the European Union, its area of occupancy has decreased, thereby this species has become vulnerable at European Union level. The main threats are the small size populations, low genetic diversity and genetic erosion of populations, habitat degradation and chemical pollutions of waters by herbicides and fertilizers used in modern agricultural practice.