Diatom diversity of springs and spring-fed streams in Vitosha Nature Park, Bulgaria

Abstract

The paper presents the first contemporary study of the diatom diversity of the springs, spring-fed streams, peat bogs and mires forming the headwaters of three rivers (Bistrishka River, Boyanska River and Strouma River) in Vitosha Nature Park. Diatom samples were collected from all natural substrata at each sampling site – epilithon, epiphyton and epipelon. A total of 353 taxa (298 species, 53 varieties and 2 forms) belonging to 70 genera were found. The highest number of species was observed in the genera Navicula s.l., Achnanthes s.l., Pinnularia, Gomphonema and Eunotia. Fifty-nine taxa are new to the Bulgarian algal flora, and 305 taxa are reported for first time for Vitosha Mountain. The dominant structure of the diatom communities was identified and the number of rare and threatened species was assessed. One hundred and seven taxa (30% of all taxa found in the study) are included in the Red List of limnic diatoms of Central Europe. Notes on some interesting taxa are provided.