Distribution and Importance Value Index of Woody Species Under Different Successional Stages at Jello-Muktar Dry Afromontane Forest, South-eastern Ethiopia

The study was conducted in protected woodland and free graze woodland located in Dugda Woreda, Oromia state, Ethiopia. The objective of the study was to explore the floristic composition, structure, and regeneration of woody species. In the park, the vegetation ecology has not been studied up to date, which is necessary for conservation. The systematic sampling technique was used to collect vegetation and human disturbance (presence and absence) data from August to December 2017. The vegetation data were collected from 30 plots from each woodland with a size of 900 m2 (30 m × 300 m) for tree/shrub, while subplots of size 400 m2 (20 m × 20 m) for sapling, respectively, were established in the main plots. Individual tree and shrub diameters at breast height (DBH) ≥2.5 cm and height ≥ 2 m were measured using a tape meter and clinometer, respectively. Diameter at breast height (DBH), frequency, density, basal area, and importance value index (IVI) were used for vegetation structure description, while the densities of mature trees, sapling, and seedling were used for regeneration. A total of 446 individual stems from free grazed woodland and 641 individual stems from protected woodland with a DBH of ≥2.5 cm were encountered from 30 studied sample plots that are protected and free grazed woodlands. Of these, from the total woody species, 68.42% were trees and 31.57% shrubs found in protected woodland; 76.92% were trees and 23.07% shrubs found in free grazed woodland. The total basal area of the woody plant was 3.1 ± 1 m2/ha in free grazed woodland and 4.2 ± 2 m2/ha in protected woodland, calculated for 19 woody species. Fabaceae, Balanitaceae, Capparidaceae, Verbenaceae, and Boraginaceae families were the most abundant families in both woodlands. However, there is a good initiation for the conservation of the park; still, the vegetation of the park was threatened by human-induced fire following intensive farming, gold mining, and overgrazing.

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Predicting population status of gum and resin bearing plant species from size distributions in Benishangul Gumuz Regional State, Ethiopia: Inferences for their sustainable management

Open Access Research Journal of Multidisciplinary Studies ◽

10.53022/oarjms.2021.1.1.0017 ◽

2021 ◽

Vol 1 (1) ◽

pp. 022-031

Author(s):

Dereje Mosissa ◽

Girum Faris ◽

Sisay Aman

Keyword(s):

Basal Area ◽

Woody Species ◽

Small Scale ◽

Older Individuals ◽

Importance Value Index ◽

Importance Value ◽

Continuous Growth ◽

Regeneration Status ◽

Regional State ◽

Good Reproduction

Diversity, population structures and regeneration status of gum- and resin- producing woody species, were assessed in 116 sample plots, each measuring 400 m2 and established along line transects. The data were collected in two selected districts, namely, Sherkole and Kurmuk in Benishangul-Gumuz National Regional State, one of the gum and resin belts in western Ethiopia. The gum- and resin-producing woody species had 1.04 and 0.7 diversity and 0.576 and 0.49 evenness values at Kurmuk and Sherkole districts, respectively. They accounted for 26% and 46% of the density, 51% and 58% of the basal area and 32% and 53% of the Importance Value Index of all the woody species, respectively. The gum- and resin- bearing woody species exhibited three patterns of population structure. The first pattern suggests good reproduction abilities of the species coupled with good recruitment of seedlings and their subsequent continuous growth to replace older individuals over time, indicating stable regeneration. About 61% of the gum- and resin- bearing woody species fall under this category. The other two patterns indicate hampered regeneration status of the woody species. Heavy grazing, conversion to crop land by small scale farming, gold mining, recurrent fire and climate change were mentioned as major bottlenecks of natural regeneration and recruitment. Policy, extension and research recommendations are discussed.

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Analysis of the Structure and Diversity of Prosopis africana (G. et Perr.) Taub. Tree Stands in the Southeastern Niger

Journal of Plant Studies ◽

10.5539/jps.v5n1p58 ◽

2016 ◽

Vol 5 (1) ◽

pp. 58

Author(s):

Laouali Abdou ◽

Boubé Morou ◽

Tougiani Abasse ◽

Ali Mahamane

Keyword(s):

Diversity Index ◽

Similarity Index ◽

Woody Species ◽

Importance Value Index ◽

Importance Value ◽

Rural People ◽

Regeneration Rate ◽

Trunk Diameter ◽

Prosopis Africana ◽

Diameter Structure

All parts of Prosopis africana are used by rural people in Niger, and this exposes it to degradation and a regeneration problems. The objective of this study was to determine the structure and regeneration of P. africana stands in the southern regions of Maradi and Zinder, Niger. Data were collected in plots, following transects after stratified sampling. Trunk diameter of all woody species was recorded in 126 plots. The diversity was analyzed and diameter structure and regeneration rates were determined. P. africana was the predominant species in both Maradi and Zinder: frequency = 40.35% and 43.95% of all species, respectively in Maradi and Zinder; importance value index = 40.57% in Maradi and 48.60% in Zinder. The Shannon diversity index was 2.82 in Maradi and 2.40 in Zinder and the Sorensen similarity index between the two regions was 0.73. According to the diameter structure, the stands were degraded in Zinder but regenerating in Maradi. The density of P. africana per hectare for trees with trunk diameter > 5 cm and < 5 cm, respectively was 16 and 51 in Maradi, and 30 and 12 in Zinder. The regeneration rate of P. africana was low compared with the general woody population. These results show the need for reforestation operations, using appropriate techniques, to avoid local extinction of the species.

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