Description:
Understanding forest stand structure is necessary for predicting losses and storage of
carbon in forests. However, there is scanty knowledge on relationship between stand
structure and carbon storage. This study assessed stand structure and its relationship with
carbon storage in Nilo Nature Reserve. The specific objectives were to determine the
forest stand structure, above ground and soil carbon stock and their relationship. The
forest was stratified into four elevation bands. Four marked permanent sample plots of size
0.4 ha with 80 subplots of size 20 × 10 m one in each elevation band was established. In
each plot, the following information was collected: tree diameter at breast height, wood
cores, and soil samples. The data was used to determine species richness, stem density,
basal area, volume and carbon stock. ANOVA was used to test variation in stand structure
and carbon stock with elevation bands while regression analysis was used to determine
their relationships. A total of 77 species of trees and shrubs belonging to 29 families were
identified. Shannon index was 3.60 indicating high plant species diversity. The stand
density, average diameter, basal area and volume were 299 ± 26 stems ha -1 , 26.07 ± 2.88
cm, 38.08 ± 3.61 m 2 ha -1 and 488.35 ± 56.32 m 3 ha -1 respectively. Above ground and soils
carbon stocks were 291 ± 32.81 and 247.13 ± 73.38 t ha -1 respectively. There was
significant correlation (P = 001) between carbon stocks and tree diameter, basal area and
volume. Average diameter, basal area, volume and above ground carbon stock were
significantly higher at high elevation than mid-high elevation band. It is concluded that
stand structure correlated with carbon stocks and NNR has high potential for carbon
storage in above ground biomass and soils. The stand structure parameters can be used
adequately for prediction of carbon stock in similar forests.