Species diversity, population structure and regeneration status of woody species on Yerer Mountain Forest, Central Highlands of Ethiopia

Abstract

Yerer Mountain forest is one of the few remaining dry Afromontane forests found in the central highlands of Ethiopia. Information on woody species composition, diversity and regeneration status in the aforementioned forest are lacking. The study, therefore, aims to study the diversity, population structure and regeneration status of woody species in the Forest of Yerer Mountain. Data were collected using 36 main plots of size 20 m × 20 m for tree/shrub. Two 5 m × 5 m (opposite corner) and five 2 m × 2 m (four at the corner and one at the center) subplots were established in the main plot sapling and seedling, respectively. DBH, height of trees and environmental data (altitude, latitude, longitude, aspect and slope) were recorded. Thirty-one indigenous woody species that belong to 23 families were observed. The Shannon-Wiener diversity indices of woody species in the study sites were 2.0, 2.14 and 2.38 in the higher, middle and lower altitude, respectively. The density of seedling, sapling, shrubs and trees were 6383, 1022,481 and 115 ha, respectively. Seven woody species (Juniperus procera, Pittosporum abyssinicum, Buddleja polystachya, Rhus retinorrhoea, Croton macrostachyus, Prunus africana and Acacia bussei) dominated the forest while Juniperus procera is the most dominated one (95 %). The structural analyses of the whole community of the study area shows a reverse “J” shape pattern, which indicate healthy regeneration status of woody species. However, the population structure of the aforementioned dominant species exhibited unhealthy structure. The study concluded that the forest is diverse, however, dominated by small-sized tree/shrub species that is under early stage of succession after disturbance. Therefore, intervention of forest management practices to enhance its diversity and natural regeneration is needed.