Ecology of vascular epiphytic plants in gedeo agro- forestry system, southern ethiopia

The Ecology of vascular epiphytes was studied in agro forestry system of Gedeo Zone, Southern Nation, Nationalities and Peoples National Regional State of Ethiopia at an altitude of 1370 -3100m. Systematic sampling method was employed during data collection. Different software’s like CANOCO, TWINSPAN, PAST and SPSS were used to analyze the data and also qualitative analysis was followed depending up the raw data collected. Eleven species of vascular epiphytes were recorded from nine host (phorophyte) species in the study area. The analysis by TWINSPAN and ordination showed as there are two plant community associations without vegetation disparity among the zone and ferns were the species rich group. The species diversity of vascular epiphyte is greatly influenced by the host tree biophysical factors, such as vertical gradient of host, bark texture, size, age, and surface area. The changing forest structure across altitude provides different quantities and qualities of substrate to epiphytes that resulted in decreasing number of epiphyte species with increasing elevation. The altitudinal distribution of epiphytes may be influenced by altitudinal factors like temperature and moisture. The vertical distribution of vascular epiphytes along the vertical gradient of the host trees indicated that most species were localized at the intermediate height. The vertical ecological gradients (i.e. solar radiation and humidity differences from the forest floor to the canopy) may be relevant for the distribution of epiphyte floras. The host tree specificity of vascular epiphytes was not exhibited by the current study. The species richness of epiphytic plants varies depending up on the season. Therefore one who wants to conduct further research on the aspect of epiphytic plants should be care of the season at which the study is conducted.