Abstract
The epiphytic bryophytes on tree trunks as well on branches and twigs of the canopy were studied in a montane rain forest in the Andes 110 km SW of Quito at about 2000 m elevation. Ten trees were examined on which 65 species (24 mooses and 41 liverworts) were found. The bryophyte flora of the stems consists of 14 species and is related on a level of up to 80%. The branches are inhabited by 58 species. The composition of species on branches of different trees (except those from the same trees) have a correspondence of less than 40%. The correspondence of the bryophytes on twigs of different trees is even lower. Twigs are inhabited by 24 species. Correlation analysis between species numbers and ecological factors revealed no significant correlation between species number and branch diameter, branch exposition and elevation. However, a correlation was found between increasing pH of the bark and decreasing species numbers. The average dry weight of epiphytic bryophytes was 80g/m2 on trunks, 1873 g/m2 on branches and 1230 g/m2 on twigs. The average water storing capacity of epiphytic bryophytes is 0.57 l/m2 on trunks, 19,5l/m2 on branches and 4.16 l/m2 on twigs and is thus ten times of the dry weight on branches but three times of dry weight on twigs. A representative tree of 27 m height has an average 65,4 kg dry weight of epiphytic bryophytes, which can store 669 liters of water. 10600 kg phytomass per hectare are estimated.