Floristic composition and plant community types of Agama Forest, an Afromontane Forest in Southwest Ethiopia

Abstract

Tropical Afromontane forests are among the most species-rich ecosystems on earth and comprise exceptional species richness and high concentrations of endemic species. The natural forest of Agama, an Afromontane forest, was studied with the objectives of determining its species composition, diversity and community types. Systematic sampling design was used to collect vegetation data. Soil samples were taken from each relevé at a depth of 0 to 30 cm and soil pH, sand, clay and silt were analyzed. The plant communities' classification was performed using the hierarchical cluster analysis. We evaluated species richness, eveness (Pielou J' index) and diversity (Shanon-Wiener index). Sorensens's similarity ratio was used to compare Agama forest with other similar forest in Ethiopia. A total of 162 plant species, 130 genera and 70 families were recorded from which Acanthaceae and Rubiaceae were the richest families. Furthermore nine endemic plant species were identified. In this study, four plant community types were identified and described. Post-hoc comparison of means among the community types showed that altitude was differed significantly between community types, indicating altitude is the most important factor in determining community type. Phytogeographical comparison of Agama Forest with other vegetation using Sorensens's similarity ratio revealed the highest similarity with Masha and Godre forest. In conclusion Agama forest presents high richness, diversity and endemism, with different plant communities according to altitude. Thus conservation of plant biodiversity is highly recommended.

Local Agroforestry Practices for Food and Nutrition Security of Smallholder Farm Households in Southwestern Ethiopia

“…The original vegetation is mainly a result of the local topography and ecological factors. These results agree with those of Addi et al [64], who focused on the correlation of natural vegetation composition and altitude in southwestern Ethiopia, and those of Bajigo et al [17], who observed a similar association of altitude with woody species diversity in HG of the Wolayita zone.…”

The effect of elevation on species richness in tropical forests depends on the considered lifeform: results from an East African mountain forest

“…1). The KBNP is part of the Mitumba Mountains, along the Western Rift, which are characterized by high species richness and many endemic species (Plumptre et al 2003;Admassu et al 2016). In this park, the elevation stretches from 650 to 3315 m asl .…”

“…Mountain ecosystems account for approximately one-fifth of the Earth's land surface (Tse-ring et al 2010;Price et al 2011) and tropical mountain forests represent about 11% of tropical forests over the world (Doumenge et al 1995). Species richness is particularly high in these ecosystems and they are often biodiversity hotspots (Bussmann 2001;Plumptre et al 2003;Tse-ring et al 2010;Price et al 2011;Admassu et al 2016). In these mountain ecosystems, elevation strongly influences the distribution of their biodiversity (Doumenge 1998;Eilu et al 2004;Hemp 2009;Pickering and Green 2009;Chain-Guadarrama et al 2012).…”

Floristic composition and vegetation community analysis of Gesha and Sayilem Forest in Kaffa Zone south western Ethiopia

“…Previous studies in Ethiopia e.g. Friis (1992); Kumelachew and Tamrat (2002); Friis et al 2011; Abreham et al (2013) and Admassu et al (2016) have confirmed that the montane moist forest ecosystems are the most diverse ecosystems in composition, structure and habitat types.…”