Woody Species Composition, Plant Communities, and Environmental Determinants in Gennemar Dry Afromontane Forest, Southern Ethiopia

Abstract

Dry Afromontane forests in Ethiopia are vital for the conservation of plant diversity and climate change mitigation. However, these forest resources are rapidly degrading and shrinking, necessitating empirical scientific investigations to ensure their successful conservation and long-term management. As a result, this study was conducted to evaluate the composition, plant communities, and environmental determinants of woody species in the Gennemar dry Afromontane forest of southern Ethiopia. Environmental variables such as altitude, aspect, and geographical location were recorded from 46 plots of 20 × 20 m for trees and 92 subplots of 10 × 10 m for shrubs were laid along 10 transect lines. Vegetation structure, diversity, vegetation classification, importance value index (IVI) and correlation with environmental parameters were analyzed. A total of 55 woody species belonging to 51 genera and 34 families were identified. Among the species identified, Jasminum stans, Maytenus addat, and Pittosporum abyssinicum were endemic to Ethiopia. Celastraceae (with 659 individuals) was the most dominant family, followed by Cupressaceae (268 individuals) and Myrsinaceae (222 individuals). Four plant communities were identified: Syzygium guineense-Mystroxylon aethiopicum, Maytenus arbutifolia-Podocarpus falcatus, Myrsine africana-Erica arborea, and Juniperus procera-Carissa spinarum. Juniperus procera, Podocarpus falcatus, and Maytenus arbutifolia were species with the highest IVI, while Maesa lanceolata, Rhamnus prinoides, and Gnidia glauca had the lowest. The DBH class distribution shows an inverted J-shaped distribution. As DBH increases, the number of individuals decreases in the higher DBH class. The distribution of plant communities and the composition of the species depend on altitude and topographic aspects. The study found that the dry Afromontane Forest is rich in species and that it should be prioritized for conservation to protect endemic and native species. Decisive elements such as the type of species, altitude, and topographic aspects must be considered for forestry activities.

Diversity, Structural, and Regeneration Analysis of Woody Species in the Afromontane Dry Forest of Harego, Northeastern Ethiopia

“…In the present study, shrubs had the largest proportion (54%) of growth habits. Similar finds were also reported at Gennemar dry Afromontane forest, 56.4% [94]; Yegof mountain forest, 51.3% [95]; Gelawoldie forest, 50.8% [89]; Zengena fores, 46% [88]; Kumuli forest, 44% [96]; and Gra-Kahsu natural vegetation, 39.53% [42], of the total growth habits of the species. e cause of the low tree species composition is due to intensive logging of useful species for timber and fuelwood [97], which in turn significantly altered their species composition with the dominance of pioneers and shrubs [4,31].…”

“…e DBH and height class distribution of the Harego forest have shown the dominance of small-sized individuals in the forest. Similar findings have been reported in other dry Afromontane forests such as Menfeskidus Monastry forest [66], Sirso forest [76], Wurg forest [77], Ambo State forest [83], Dello Mena forest [84], Brandi forest [85], Woynwuha forest [86], Gelawoldie forest [89], Gennemar dry Afromontane Forest [94], Kumuli forest [96], Wanzaye forest [100], Amoro forest [102], and Sesa Mariam Monastry forest [109]. is revealed a healthy regeneration but low in recruitment [34,103,127].…”

Floristic Composition and Structural Analysis of Woody Plant Species in Jib Godo Natural Forest, Farta District, South Gonder Zone, Amhara Region, Ethiopia

“…Following reference [2], environmental parameters (altitude, slope, and aspect) of the Jib Godo Natural Forest were measured. Te global positioning system was used to determine altitude.…”

“…Te analysis was based on the species' abundance. Te community types discovered by cluster analysis were refned further in a synoptic table, which summarized species occurrences as synoptic coverabundance values [2]. Te Jaccard similarity coefcient was used to compare the similarity between the community types.…”

“…Ethiopia is a mountainous nation with contrasting landscapes including rough mountains, plateaus, deep gorges and river valleys, and undulating plains. Its elevation ranges from 4,620 meters at the highest peak of the Ras Dejen to 110 meters below sea level in the Dallol valley [2]. Ethiopia is endowed with a highly diversifed climatic conditions and topography with a wide range of habitats and vegetation types.…”