Macrophyte vegetation of the middle course of Mreznica river

Makrofiti su dobri indikatori stanja rijeke jer brzo odgovaraju na promjene u fizikalno-kemijskim svojstvima, brzini ili razini vode. Cilj ovog rada bio je istražiti sastav i strukturu makrofitske vegetacije srednjeg toka rijeke Mrežnice i ocijeniti njeno biološko stanje. Istraživano je ukupno 14 lokaliteta i zabilježeno ukupno 48 makrofitskih vrsta. Najviše je bilo zakorijenjenih vaskularnih biljaka koje rastu u sporijim i dubljim dijelovima rijeke i pojavljuju se u više morfoloških oblika, a svrstavamo ih u Sparganium emersum zajednicu. Mahovine su s najvećom pokrovnošću rasle na sedrenim barijerama, a pripadale su Berula-Agrostis zajednici koja je značajna za sedrene slapove. Na ovom tipu staništa bila je i najveća bioraznolikost i homogenost makrofitske vegetacije. Ukupno je bilo devet vrsta zaštićenih na nacionalnoj razini, jedna je vrsta bila strogo zaštićena sa statusom ugrožene svojte (EN), a jedna vrsta imala je status nedovoljno poznate (DD) prema kriterijima Međunarodne unije za očuvanje prirode (IUCN). Na temelju analize makrofita, biološko stanje srednjeg toka Mrežnice svrstava se u vrlo dobro stanje (klasa 1). Ovaj rad pomnije istražuje makrofitsku vegetaciju rijeke Mrežnice i može poslužiti za daljnji monitoring koji je važan za izradu plana upravljanja i zaštite.Macrophytes are good indicators of the river condition because they respond quickly to the changes in physico-chemical parameters, velocity or the level of water. The aim of this study was to investigate the composition and structure of macrophyte vegetation of the middle course of the Mrežnica River and evaluate its biological condition. A total of 14 sites were investigated resulting in 48 recorded macrophyte species. The majority of species were rooted vascular plants that grow in slower and deeper parts of the river and appear in several morphological forms that are classified in Sparganium emersum community. The highest coverage of mosses was found on travertine barriers. They belonged to the Berula-Agrostis community that is significant for travertine waterfalls. This type of habitat had the highest biodiversity and homogeneity of macrophyte vegetation. Nine species were protected at the national level, while one was strictly protected with the status of endangered species (EN), and one was classified in the data-deficient category (DD) according to the criteria of the International Union for Conservation of Nature (IUCN). Based on the analysis of macrophytes, the biological condition of the middle course of the Mrežnica River is classified as “in very good condition” (class 1). This work closely examined the macrophyte vegetation of Mrežnica and can be used for future monitoring, which is important for the development of the management and protection plans