1.2. Interest of the study
Savanna ecosystems of West Africa including those of Benin and
Côte d'Ivoire are overexploited. Agriculture by burning, village hunting,
overgrazing and fire misuse increased the fragmentation of species habitats
with increasing shortage of biodiversity and climate change as direct feedback.
Fire misuse profits just within short time only for its users but its
disadvantages span over a longer time for all mankind. This threat on sudanian
resouces lead to the disappearance of plant and animal sp ecies. The
conservation of the endangered species should require a great description and
analysis of their habitats. For that purpose, research on the population
dynamics of tree-species in their ecological biotop e become important to
understand destructive process of anthropogenic pressure on the habitats of
species. Tree species like A. leiocarpa, I. doka, P. erinaceus, D.
microcarpum, and D. abyssinica are characteristics of the savanna
areas from Upper Aguima C atchment (Benin) and Comoé
National Park (Côte d'Ivoire) and some of these species
are endemic to the sudanian region depending the phytogeographical
classification of White (1983). Therefore, this research aimed to trace the
fire history from fire scars o bserved on the tree-rings. Thus, the frequency
of fire use in these studied areas and the number of years required for these
five species to become fire-resistant will be determined.
1.3. Aims
The study aimed at contributing to a better management and
conservation of West African tree species on the basis of their annual growth.
Therefore, five specific objectives were defined:
> to describe the wood anatomy of the sampled tree species;
> to determine the age of sampled trees;
> to determine the growth performances of sampled species in
their biotope ; > to synchronize fire scars for each of these species;
> to analyse fire regime in both sites.
1.4. Research questions
To achieve the above objectives, the following questions were
raised:
> does wood anatomy vary among species ?
? can the observed tree rings be interpreted as annual growth
?
> how long do tree species need to reach the height of 1.3 m
chosen as reference for dbh measure?
> which one of the studied site experienced more treated by
fire year round events?
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