MERWIN, MARK C. Forest Canopy Research Laboratory, Lab I-3064, The Evergreen State College, Olympia, WA 98505. - Epiphyte community composition and species diversity in primary and secondary montane cloud forest, Costa Rica.
The vegetation dynamics of non-vascular epiphytes following conversion
of primary forest due to clearing by humans was investigated. An
inventory of the epiphyte communities on twelve canopy emergent trees
was conducted in primary and 35 year-old secondary tropical montane
cloud forest in Costa Rica. Sampling included tree trunks, large
branches, and the small branches and twigs of the outer canopy. Six
Conostegia oerstediana were studied in secondary forest, and
three Meliosma vernicosa and three Ocotea tonduzii in
primary forest. Mosses, hepatics and lichens were surveyed in 256
replicate 30cm cylindrats. Substrate characteristics were measured,
and the percent cover of each species was estimated using
phytosociological methods. A reconnaissance for additional species
was conducted in the canopy, on the trunks, and from recently fallen
branches. Quantitative analyses of the community composition,
relative abundance, distribution, and epiphyte species diversity of
the two habitats are discussed. Only data for the mosses are
presented, as identifications of hepatics, marco- and crustose lichens
are currently underway.
Key words: Costa Rica,disturbance,diversity,epiphytes,moss,tropical cloud forest