Moreover, the study shows that aboveground
carbon stocks vary across forest stands. The results suggest that
stand age is one of the most important factors explaining the variation
in aboveground carbon stock among forest stands. For
instance, the disturbed primary forest had significantly more
aboveground carbon than all other forest types. Similarly, mixed
indigenous plantation forest and old-growth secondary forest
stands had more aboveground carbon stock than relatively
younger secondary and plantation forest stands. The role of stand
age in explaining the variation in aboveground carbon stock among
forest stands is attributable to the fact that older tree stands often
comprise relatively larger trees, which, as illustrated by Omeja
et al. (2011) and Ifo et al. (2014), tend to hold more aboveground
carbon than younger forest stands. The results reaffirm the role
of old-growth forest stands, such as the disturbed primary forest,
old-growth secondary forest and mixed indigenous plantation, as
major terrestrial carbon sinks (Stegen et al., 2011) whose disturbance
may have a significant impact on the global carbon balance.