Ugroženi bazofilni cret uz potok Jarak (Park prirode Žumberak-Samoborsko gorje, Hrvatska)

This study presents the results of floristic research into a flat fen along a part of the Jarak stream in Žumberak-Samoborsko gorje Nature Park. This fen belongs to order Caricetalia davallianae Br.-Bl. 1949, alliance Caricio davallianae Klika 1934, association Eriophoro latifolio-Caricetum panicae Horvat ex Trinajstić 2002. The area was researched in 2007/2008 and it was divided into four subareas: fen and three succession stages, Phragmites subarea, transitional stage between common reed (Phragmites australis) and young forest, and young forest. During the winter period of the research the overgrowing woody vegetation on three subareas was cut, because that action should prevent further succession and help the restoration of the fen. The following year, floristic changes were monitored. Recorded plants were taxonomically analyzed and ecological indicator values according to Landolt were calculated. During this study 222 plant species were found, out of which 15 were endangered (according to IUCN categorization) and 59 protected or strictly protected in Croatia. The summarized ecological indicator values according to Landolt showed only minor differences between the subareas, out of which only the young forest subarea stood out. The removal of the plants resulted in low floristic changes, present mostly in the young forest subarea, where species of open habitats enlarged their abundance, but no characteristic fen species were recorded. It is concluded that the fen along the stream Jarak should be protected, because of its rare vegetation type, but also because of the endangered and protected species found in this area. It is also necessary to carry out regular removal of overgrowing vegetation from all the subareas and multiple mowing to protect the fen and even enlarge its surface