Fitocenologija in ekologija vrste Cressa cretica L. (Convolvulaceae) na vzhodni jadranski obali

The present phytosociological study of the eastern Adriatic coastal salt-marsh at Blato, Croatia, is based on the Braun-Blanquet approach. Five plant associations were recorded in the area: Juncetum maritimo-acuti, Puccinellio festuciformis-Sarcocornietum fruticosae, Scirpetum maritimi, Enteromorpho intestinalidis-Ruppietum maritimae and Cressetum creticae. The association Cressetum creticae was found for the first time in Croatia as well as on the eastern Adriatic coast. This therophytic and halo-nitrophilous association shows a monospecific or paucispecific character and occupies the most haline and the driest parts of the salt-marsh. The association develops during the summer on silty clay substrates with organic matter derived from the decay of plants of the neighboring communities. According to key soil factor analysis no differences of grain size of the soils among the associations were found, while regarding electrical conductivity, Cl- and Na+ concentrations were higher in the Cressetum creticae than in any of the others associations. The particular original features of the site regarding its flora and vegetation would justify some measures of protection and management.Predstavljamo fitocenološko raziskavo obalnega slanega mokrišča Blato (Hrvaška) v vzhodnem Jadranu, ki smo jo naredili po Braun-Blanquetovi metodi. V raziskovanem območju smo zabeležili pet asociacij: Juncetum maritimo-acuti, Puccinellio festuciformis-Sarcocornietum fruticosae, Scirpetum maritimi, Enteromorpho intestinalidis-Ruppietum maritimae in Cressetum creticae. Asociacija Cressetum cretice je na ozemlju Hrvaške in tudi na vzhodni obali Jadranskega morja opisana prvič. Terofitska in halo-nitrofilna asociacija je monospecifična ima siromašno vrstno sestavo in se pojavlja na najbolj slanih in suhih delih slanišča. Sestoji se razvijajo poleti na glineni podlagi z organsko snovjo, ki jo sestavljajo odmrli rastlinski deli s sosednjih združb. Analiza tal je pokazala, da med asociacijami ni bilo razlik v velikosti talnih delcev, električni onduktivnosti, koncentraciji Cl- in Na+ ionov pa sta bili v asociaciji Cressetum creticae višji kot ostalih asociacijah. Zaradi posebnosti v flori in vegetaciji bi bilo potrebno na preučevanem območju zagotoviti določene mere zaščite in ustrezen način upravljanja