Abstract:
The significant role of tropical forest ecosystems
in the global carbon budget has increased the need for
accurate estimates of tropical forest biomass. The lack of
large-scale biomass allometric equations hampers the
understanding of the spatial distribution of tree biomass
and carbon stocks and their influencing factors in West
Africa. This study aimed to develop allometric equations to
estimate aboveground biomass of African oak (Afzelia
africana Sm.) in Burkina Faso and to analyze factors
affecting the variability of tree biomass and carbon storage.
Sixty individual trees were destructively sampled in four
protected areas along two climatic zones. In each climatic
zone, log–log models were tested and fitted to each
aboveground biomass component and to the total aboveground biomass. Carbon content in tree aboveground
components was evaluated using the ash method. All validated equations showed good fit and performance with
high explained variance. Allometric equations differed
between the Sudano-sahelian zone and the Sudanian zone,
except for leaf biomass equations. Both biomass allocation
and carbon content varied significantly between tree components but not between climatic zones. Carbon content in
tree components followed the patterns of biomass allocation with branches accounting for the highest proportion. In
the two climatic zones, carbon contents were
50.18–52.62% for leaves, 54.78–54.94% for stems and
54.96–55.99% for branches. Dry biomass ranged from
509.05 to 765.56 kg tree-1 at site level and from 620.21 to
624.48 kg tree-1 along climatic zones. Carbon content
varied from 53.90% in the Sudano-sahelian zone to 54.39%
in the Sudanian zone. This study indicated that climate
does not influence aboveground biomass production and
carbon sequestration of Afzelia africana along the Sudanosahelian and the Sudanian climatic zones of Burkina Faso.
Future studies on climate–growth relationships should
contribute to better understanding climate effects on biomass production and carbon storage.
