Expertise: Phycological research, including diatoms as water quality indicators, cyanobacterial systematics, and floristics of terrestrial algae
I am interested in the taxonomy, ecology, and systematics of algae, and conduct work in freshwater lakes and rivers as well as subaerial habitats such as wet rock walls and soils. Although I work and publish on all algal phyla, my primary expertise and interest lie in the cyanobacteria and diatoms. With regards to cyanobacteria, I have been a part of the discovery and naming of several new genera and species, and my work is both in microscopical examination and sequencing of the 16S rRNA gene and the associated 16S-23S ITS region. I have also described new genera and species of diatoms, as well as published some diatom floras. My floristic survey work takes me and my students to many interesting places, such as Acadia National Park, Great Smoky Mountains National Park, Grand Staircase-Escalante National Monument, and the Atacama Desert in Chile. All of my work is collaborative in nature, and I enjoy working with students and faculty at John Carroll University as well as faculty and students at other universities in the USA and around the world.
FYS-SEM – First Year Seminar
PH 115/115L Environmental Earth Science
BL 159/BL 160 – Biodiversity
PH 206 Earth Systems Science
BL 331 – Global Climate Change
BL 445 – Aquatic Resources
BL 447 – Algae as Bioindicators
Johansen, J.R., M. Bohunická, A. Lukešová, K. Hrčková, M.A. Vaccarino and N.M. Chesarino. 2014. Morphological and molecular characterization within 26 strains of the genus Cylindrospermum (Nostocaceae, Cyanobacteria), with descriptions of three new species. Journal of Phycology 50: 187-202.
Lowe, R.L., J.P. Kociolek, J.R. Johansen, B. Van De Vijver, H. Lange-Bertalot and K. Kopalová. 2014. Humidophila gen. nov. a new genus for a group of diatoms (Bacillariophyta) formerly within the genus Diadesmis: species from Hawai’i, including one new species. Diatom Research 29: 351-360.
Mühlsteinová, R., J.R. Johansen, N. Pietrasiak and M.P. Martin. 2014. Polyphasic characterization of Kastovskya adunca gen. nov. et comb. nov. (Oscillatoriales, Cyanobacteria) from desert soils of the Atacama Desert, Chile. Phytotaxa 163: 216-228.
Mühlsteinová, R., J.R. Johansen, N. Pietrasiak, M.P. Martin, K. Osorio-Santos and S.D. Warren. 2014. Polyphasic characterization of Trichocoleus desertorum sp. nov. (Pseudanabaenales, Cyanobacteria) from desert soils and phylogenetic placement of the genus Trichocoleus. Phytotaxa 163: 241-261.
Kaštovský, J., E. Berrendero-Gomez, J. Hladil and J.R. Johansen. 2014. Cyanocohniella calida gen. nov. et spec. nov. (Cyanobacteria: Aphanizomenonaceae) a new cyanobacterium from the thermal springs from Karlovy Vary, Czech Republic. Phytotaxa (in press).
Veselá, J. & J.R. Johansen, J.R. 2014. Three new Eunotia (Bacillariophyta) species from Acadia National Park, Maine, USA. Phytotaxa (in press)
Řeháková, K., J.R. Johansen, M.B. Bowen, M.P. Martin and C.A. Sheil. 2014. Variation in secondary structure of the 16S rRNA molecule in cyanobacteria with implications for phylogenetic analysis. Fottea 14: (in press).
Patzelt, D.J., L.Hodač, T. Friedl, N. Pietrasiak and J.R. Johansen. 2014. Biodiversity of soil cyanobacteria in the hyper-arid Atacama Desert, Chile. Journal of Phycology (in press).
Osorio-Santos, K., N. Pietrasiak, M. Bohunická, L. Miscoe, L. Kovacik, M.P. Martin and J.R. Johansen. 2014. Seven new species of Oculatella (Pseudanabaenales, Cyanobacteria): taxonomically recognizing cryptic diversification. European Journal of Phycology 49: (in press).
Wilde, S.B., J.R. Johansen, H.D. Wilde, P. Jiang, B.A. Bartelme and R.S. Haynie. 2014. Aetokthonos hydrillicola gen. et sp. nov.: Epiphytic cyanobacteria associated with invasive aquatic plants and implicated in bird deaths from Avian Vacuolar Myelinopathy. Phytotaxa (in press)
Pietrasiak, N., R. Mühlsteinová, M.A. Siegesmund and J.R.. Johansen. 2014. Phylogenetic placement of Symplocastrum (Phormidiaceae) with a new combination S. californicum and two new species: S. flechtnerae and S. torsivum. Phycologia (in press)
Sherwood, A.R., A.L. Carlile, M.A. Vaccarino and J.R. Johansen. 2014. Diversity of Hawaiian freshwater and terrestrial cyanobacteria characterized for the Hawaiian Freshwater Algal Biodiversity Survey. Phycological Research (in press)
Bohunická, M., J.R. Johansen and K. Fučíková. 2011. Tapinothrix clintonii sp. nov. (Pseudanabaenaceae, Cyanobacteria), a new species at the nexus of five genera. Fottea 11: 127-140.
Vaccarino, M.A. and J.R. Johansen. 2011. Scytonematopsis contorta sp. nov. (Nostocales), a new species from the Hawaiian Islands. Fottea 11: 149–161.
Pietrasiak, N., J.R. Johansen, R.E. Drenovsky. 2011. Geologic composition influences distribution of microbiotic crusts in the Mojave and Colorado Deserts at the regional scale. Soil Biology & Biochemistry.63: 967-974.
Johansen, J.R., L. Kovacik, D.A. Casamatta, K. Fučíková and J. Kaštovský. 2011. Utility of 16S-23S ITS sequence and secondary structure for recognition of intrageneric and intergeneric limits within cyanobacterial taxa:Leptolyngbya corticola sp. nov. (Pseudanabaenaceae, Cyanobacteria). Nova Hedwigia 92: 283-302.
Veselá, J. and Johansen, J.R. 2009. The diatom flora of headwater streams in the Elbsandsteingebirge Region of the Czech Republic. Diatom Research, 24: 443-477.
Fučíková, K., J.D. Hall, J.R. Johansen and R.L. Lowe. 2008. Desmid flora of the Great Smoky Mountains National Park, USA. Bibliotheca Phycologica 113: 1-59.