This is the first part of an ongoing taxonomic treatment of Bunodophoron (Sphaerophoraceae, Lecanorales) in the Neotropics, based on the molecular phylogenetic analysis of three markers together with studies of morphology and chemistry, and using the general mixed Yule coalescence (GMYC) method to delimit species boundaries. In the Neotropics, species in this genus grow on the ground or on shrubs in the páramos, and as epiphytes in the montane rainforests. We describe here a new species from the páramos of Colombia, Bunodophoron crespoae Soto, M. Prieto & Wedin sp. nov., and discuss its distinction from another large and common páramo species Bunodophoron flabellatum (Hue) Soto, M. Prieto & Wedin comb. nov. Both species are primarily terrestrial in the páramos, although B. flabellatum may occasionally also grow as an epiphyte. Bunodophoron crespoae is characterized by the white, c. 10–13 cm long, subterete to narrowly flattened, main branches. It differs from the otherwise similar B. flabellatum by being distinctly subterete, more abundantly branched, and by having smaller ascospores. Both are distinguished from the primarily epiphytic B. melanocarpum by the considerably larger thallus size, with the main branches of B. melanocarpum rarely exceeding 3·5 cm in length and 2 mm in width.

The development of metacommunity theory, which suggests that the diversity and composition of communities is influenced by interactions with other communities, has produced new tools for evaluating patterns of community change along environmental gradients. These techniques were used to examine how plant communities changed along elevation gradients in montane tropical forests. Two transects of 0.1-ha vegetation plots were established every 50 m in elevation in the mountains of eastern Puerto Rico. The transects ranged from 300 m to 1000 m asl and 400 m to 900 m. In each plot, all free-standing woody stems greater than 1 cm in diameter at 130 cm in height were marked, measured and identified. Additional data on three similar transects were taken from the literature. The upper or lower boundaries of species ranges were significantly clumped along all five transects. Coherence, a measure of the number of gaps in species distributions, was also significant across all transects, and three transects showed significant, albeit low, nestedness. Four sites had significant species turnover. These results suggest that metacommunity techniques can be useful in searching for patterns of community change present in montane tropical forests.