Browsing by Subject "LICHENS"

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  • Stam, Åsa; He, Xiaolan; Kaasalainen, Ulla; Toivonen, Mikko Evert; Enroth, Johannes; Räsänen, Matti; Rikkinen, Jouko (2020)
    The dispersal ecology of tropical non-vascular epiphytes has rarely been experimentally investigated. We studied epiphyte colonisation on 1 × 1 m polyethene nets placed for four years at seven sites at different elevations in montane forests in the Taita Hills, Kenya. During the first year the nets were also used to measure fog deposition. We predicted that differences in growth conditions would affect colonisation and subsequent growth of non-vascular epiphytes and result in clear differences in epiphyte cover and biomass, and community composition among sites. After four years the nets were taken down for determination of epiphyte cover and biomass. The diversity of established liverworts and macrolichens was also examined. Many liverwort and macrolichen species established diverse communities on the nets placed in the moist upper-montane zone. This was in contrast with the situation in the drier lower-montane zone where only green algae and crustose lichens were able to colonise most nets. Light intensity was an important determinant of epiphyte community composition, with liverworts dominating on nets under closed forest canopies and lichens dominating at more open sites. Atmospheric moisture was also important, with lichens benefiting from abundant fog deposition at open and windy sites. The dry weight of epiphytes (per unit area) on lichen-dominated nets was greater than on liverwort-dominated nets, while the highest cover was generally observed on liverwort-dominated nets. Our results demonstrate that polyethylene nets can be effectively used to study colonisation of non-vascular epiphytes as well as the abiotic and biotic factors controlling epiphyte colonisation and community composition in tropical forests. The liverworts Acanthocoleus chrysophyllus and Diplasiolejeunea kraussiana were new additions to the Kenyan bryophyte flora.
  • Pino-Bodas, Raquel; Ahti, Teuvo; Stenroos, Soili (2020)
    This study was focused on two species of lichen-forming fungi from Madagascan Region whose taxonomy has been controversial over the years, Cladonia mascarena Nyl. and Heterodea madagascarea Nyl. While some authors considered C. mascarena to belong to Cladonia, others place it in Pycnothelia Dufour. In this study three loci (ITS rDNA, rpb2 and ef1 alpha) were used to determine the phylogenetic placement of C. mascarena. Our results show that it belongs to Pycnothelia and the combination Py cnothelia mascarena (Nyl.) Nyl. is substantiated. In addition, a key to the genus Pycnothelia is provided. The morphological study of new specimens of Gymnoderma coccocarpurn Nyl. and H. madagascarea concluded that these taxa belong to a same species, confirming the extension of Gymnoderma Nyl. to Africa. The overlooked genus Baeoderma Vain. is regarded as a synonym of Gymnoderma, and its type species Baeoderma madagascareum (Nyl.) Vain. is referred to G. coccocarpum.