Floristic composition, structure and regeneration status of Riverine forest at Nech Sar National Park of Ethiopia

Abstract

analyzing floristic composition, structure and regeneration status of woody plant species. The floristic composition and population structure of woody plant species were recorded in 76 quadrats, each of which 20× 20 m 2 size. Data on species cover abundance, DBH, height and numbers of individuals per species and altitude were recorded from each quadrat. From NNP Riverine Forest 86 vascular plant species, representing 65 genera and 30 families were recorded. The family Fabaceae had the highest no. of species (11) followed by Euphorbiaceae each with 7 species, Sapindaceae and Tiliaceae each by 5 species. The four most abundant woody plant species in the forest were Lecaniodiscus fraxinifolus, Trichilia dregeana, Syzygium guineense, Euclea divinorum. Moreover, the five most frequently distributed woody plant species were Lecaniodiscus fraxinifolus, Trichilia dregeana, Syzygium guineense, Euclea divinorum and Maytenus senegalensis. Three communities: Lecaniodiscus fraxinifolius-Trichilia dregeana community, Trichilia dregeana-Syzygium guineense community and Syzygium guineense-Lecaniodiscus fraxinifolius community were recognized, with similarity coefficients of 0.65, indicating that there are moderate similarity among the communities. The Shannon-Wiener diversity and evenness in the forest were 2.92 and 0.68 respectively, indicating high diversity. The matured, sapling and seedling density of species were 1815.8(23.3%), 1344.1(17.2%) and 4635.9(59.5%) stems ha-1. The population structure in the forest revealed that there is a need of conservation for communities with poor regeneration status. problems that contribute to the destruction of natural habitats, and hence wildlife in NNP were temporary and permanent settlement, charcoal making, firewood collection, overgrazing, deliberate fire to clear the vegetation for agriculture and selective tree cutting for construction were the main threats in the NNP (Samson et al., 2010; NNP, 2015). This factor is responsible for the decline in their habitat and population density (Workneh et al., 2016). Arba Minch Natural forest was one of the forests of Nech Sar National Park victimized by these anthropogenic activities as well as environmental factors. Awareness and knowledge on sustainable use and management were very much less (Aramde et al., 2012). According to FAO (2007), the diversity, regeneration status, floristic composition, and vegetation structure are crucial elements to clearly visualize the anthropogenic activities as well as environmental factors affecting the vegetation of an area. Hence, for effective management and conservation of this unique ecosystem of the country, there is an urgent need to develop a sound management and conservation plan, and this, in turn, required Structure, diversity, species richness, regeneration, Nechsar riverine vegetation Keywords:

Woody plant diversity, composition and structure in relation to environmental variables and land‐cover types in Lake Wanchi watershed, central highlands of Ethiopia

“…The ‘bell‐shaped’ diameter distribution of DBH in the forest‐cover suggested the presence of poor regeneration and reduced recruitment capacity of the forest in Lake Wanchi watershed. A similar bell‐shaped pattern was observed by Kebebew and Demissie (2017) in riverine forest of Nech Sar National Park, Ethiopia. As indicated in our regression and ordination analysis, these deviations of tree DBH diameter distribution from the normal distribution can be largely attributed to the high anthropogenic disturbances in forest and shrublands in the watershed.…”

Typology of the woody plant communities of the Ethiopian Nech Sar National Park and an assessment of vegetation-environment relations and human disturbance impacts

“…Whereas some other studies have been carried out in the park with the aim to describe the occurring plant communities (e.g. Shimelse et al 2010;Kebebew & Demissie 2017), and to evaluate vegetation -environment relationships (Shetie et al 2017), previous studies have not been exhaustive in terms of sampling size and geographical extent, and they did not quantitatively evaluate the effects of human disturbance on vegetation composition and species richness. Yet, such a vegetation classification and better understanding of the vegetation -environment relationships and human disturbances impacts could provide the evidence-base for any management plan aiming to conserve and restore the remaining woody vegetation (Sutherland et al 2004).…”

Woody Species Composition, Structure, and Status of Regeneration in Pugnido Forest, Gambella Region, Western Ethiopia

“…Ethiopia is among the world's nations with the greatest diversity of flora and fauna [ 1 ]. The variation in topography, climate, and edaphic factors enables the country to be the owner of diverse vegetation from alpine to desert ecosystems [ 2 ]. It is Africa's fifth largest floral diversity country with nearly 6027 species of higher plants, of which about 780–840 (10%) are endemic [ 3 ].…”