| Plant succession has classically been portrayed as an orderly, directional, and predictable process of species turnover through time. Unfortunately most of the studies from which these conclusions have been drawn have been poorly replicated owing to the practical difficulties involved in following the development of an assemblage throughout its existence.;The current study has examined change over time in species cover and composition in the assemblage of epiphyllic bryophytes growing upon the fronds of the neotropical understory palm Geonoma seleri in the Monteverde Cloud Forest Preserve of northern Costa Rica. The assemblage was examined in two ways. First, change in the assemblage over time was assessed by examining the epiphyll assemblage from 914 pinnae collected from 100 individual palms and inferring chronology upon the pinnae on the basis of the position of their frond upon the palm. Second, through repeated examination of the epiphyll assemblage on 50 pinnae, from emergence of the frond to abscission, on 50 additional palms. Additionally, bryophyte propagule input, site openness, height of the palm, and seasonal effects, were examined to determine what effect, if any, these parameters had on the development of the bryophyte assemblage.;Results indicate that succession, as classically defined, does not occur in this assemblage of epiphyllic bryophytes. Assemblage composition was highly variable and significant change over time in the cover values of individual bryophyte species was largely undetected. Although the cover values of individual bryophyte species did increase over time, no stable climax community was evident. Bryophyte assemblage development was not influenced by the season during which a frond emerged. The rate at which bryophyte propagules entered the system was not an influence on the rate at which individual species increased in cover. Further, neither the canopy closure over the individual palm's location within the forest, nor the height of the palm upon which the fronds were borne had a significant effect on the total cover of the bryophyte assemblage. |
