Browsing by Author "Kainyande, Aruna"

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    Above-ground Carbon Stocks of Tectona grandis and Gmelina arborea Plantations in Njala University, Southern Sierra Leone
    (Sciencedomain International, 2022-11-09) Kainyande, Aruna
    The unprecedented increase in atmospheric CO2 concentration has attracted global research attention on the potential role of tree plantations in climate change mitigation. There is an urgent need to estimate the above-ground biomass (AGB) and carbon stock in forest plantations. This is particularly essential for Sierra Leone, where above-ground biomass (AGB) and carbon stock data are presently lacking. This study estimated the above-ground biomass accumulation and carbon stock of Tectona grandis Linn.f. and Gmelina arborea Roxb. in the spacing and plantation trials at Njala University, Southern Sierra Leone. The assessment was based on a total inventory of trees having a diameter at breast height (DBH) ≥ 5 cm and tree height. Above-ground biomass (AGB) was estimated using the allometric equation by Chave et al. (2005), and above-ground carbon (AGC) stock was calculated by multiplying the biomass with a conversion factor of 0.5. The result showed that the mean above-ground carbon stock for Gmelina arborea was higher in the plantation trial (25.2 t ha-1) than in the spacing trial (7.5 t ha-1). For Tectona grandis, the mean above-ground carbon stock was similarly higher in the plantation trial (6.6 t ha-1) than in the spacing trial (1.5 t ha-1). The results further suggest that the variation in the means of above-ground carbon stock is not dependent on the tree species type and experimental site because there were no significant differences (P>0.05) between the tree species and experimental sites.
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    Spacing Effects on the Growth and Carbon Storage of Plantation-grown Trees in the Njala University Tree- Spacing Experimental Plots, Southern Sierra Leone
    (B P International (a part of SCIENCEDOMAIN International), 2023-02-28) Kainyande, Aruna
    This study compared the growth and carbon storage of Tectona grandis, Gmelina arborea, and Terminalia ivorensis planted at four different spacings in the five-year-old spacing trial plots at Njala University; Southern Province, Sierra Leone. The spacings adopted were 1.8 m x 1.8 m, 2 m x 2 m, 3 m x 3 m, and 4 m x 4 m. The study assessed the effects of these spacings on tree growth parameters and carbon storage in the above-ground tree biomass. The species were planted in square plots consisting of four different spacings. Data was collected on tree height, diameter at breast height, and crown width. The data were subjected to analysis of variance (ANOVA) to determine significant differences in tree growth and carbon storage under different spacing levels at P < 0.05. Results revealed that spacing had a statistically significant effect on basal area per hectare (P = 0.001) and crown width (P = 0.001), with the exceptions of total tree height (P = 0.354), diameter at breast height (P = 0.234), stand volume (P = 0.131), biomass (P = 0.114) and biomass carbon (P = 0.114). The results portrayed the 1.8 m x 1.8 m spacing to lead in terms of total tree height (3.4 m) and basal area per hectare (2.15 m2 ha-1). The 2 m x 2 m gave the best results for diameter at breast height (9.18 cm) and stand volume increment (5.29 m3 ha-1), while biomass (26.4 kg) and biomass carbon (11.86 kg C) were highest in the 3 m x 3 m spacing. The widest spacing 4 m x 4 m dominated in terms of crown width increment (4.776 m). The results suggest the choice of spacing as a key determinant in achieving the intended management objectives of plantation establishment.