COMPOSITION, STRUCTURE AND REGENERATION STATUS OF SEKELE MARIAM FOREST IN DENBECHA, WEST GOJJAM, AMHARA REGION, ETHIOPIA

Abstract

Ethiopia‘s global biodiversity hotspots and their multiple benefits of today and tomorrow are facing growing challenges from the competing and conflicting demands, ineffective conservation and unwise utilization. Studies on plant species composition, structure and regeneration status help design appropriate conservation measures to halt such impacts on forest ecosystems. Therefore, this study investigated the species composition, structure and regeneration status in Sekele Mariam forest. A systematic sampling technique was used to collect data. Quadrats of 20 m x 20 m were laid for trees, shrubs and lianas of height ≥ 2 m and DBH ≥ 2.5 cm whereas herbaceous plants were sampled in five 1m x1m nested plots (one at the center and four at the corner) of the main quadrat. Individuals of trees and shrubs with DBH ≥ 2.5cm and height ≥ 2 m were counted; their DBH and heights were measured. Individuals with DBH < 2.5 cm and height < 2 m were considered for regeneration status assessment (H< 1m: seedlings; between 1-2 m: saplings and > 2 m: mature individuals) in 5m-by-5m plots.Sixty plant species belonging to 58 genera and 41 families were identified in Sekele Mariam Forest. Fabaceae was the most dominant family represented by seven (10.9%) species, followed by Poaceae (5; 7.8%), Euphorbaceae and Loganiaceae 3 (3; 4.7% each). The six most abundant species in descending order were Croton macrostachyus, Albizia gummifera, Carissa spinarum, Eleusine floccifolica, Eucalyptus citriodora and Cupressus lusitanica. The Shannon-Wiener diversity index (H‘) and evenness for the forest were 3.32 and 0.81, respectively.Based on habit distribution showed that most of the species (30; 50%) were shrubs followed by trees, herbs and lianas respectively. The population structure analysis indicated that the study forest exhibited an inverted J-shape. The densities for mature plant species, saplings, and seedlings were 646.8, 667.7, and 981.9 individuals‘ ha-1, respectively. The findings showed that the population structure and regeneration status of the forest showed that there had been substantial human disturbances and high degrees of forest degradation in the area, hence planned restoration measures are essential for sustainable use of the forest‘s genetic resources