| Titre |
Secondary succession and factors determining change in soil condition from fallow to savannah in the Sudanian Zone of Benin |
| Auteurs |
ASSEDE Emeline P. S. [1],
ADOMOU ARISTIDE COSSI [2],
SINSIN Brice [3],
|
| Journal: |
Phytocoenologia |
| Catégorie Journal: |
Internationale |
| Impact factor: |
0 |
| Volume Journal: |
42 |
| DOI: |
|
| Resume |
Demand for land for agriculture remains one of the greatest threats to the
natural vegetation in the Sudanian Zone in Africa. This study aimed to
assess the patterns of the secondary succession around the Biosphere
Reserve of Pendjari in northern Benin and to establish its relationships with
soil properties. Fallow vegetation was stratified by age and four succession
states were recognized. Phyto-ecological inventories were carried out within
plots of 30 m x 30 m. Soil physico-chemical properties were determined in
fallows that best represent the succession states. Numerical analyses of
vegetation data resulted in four fallow types, which corresponded to the four
vegetation succession states empirically recognized earlier. The first state
was characterised by the proliferation of widespread species that
disappeared by the third state. The therophytes and chamaephytes, abundant
during the first state, were replaced by hemicryptophytes and phanerophytes
in the last state. About 22% of the 233 species recorded were present
throughout the fallow cycle. The first succession state exhibited the highest
species richness with 18.6% of all species exclusive to this state. The
transition from the first to the second state was characterised by the
disappearance of 77% of the total species richness. Organic Matter and the
Species Richness were the best discriminating variables of the succession
states. Soil exchangeable cations (K+, Mg2+ and Ca2+) did not show
significant differences between the first and second succession stages, but
OM and P increased significantly along the succession gradient. The
secondary succession exhibited a clear floristic pattern with a progressive
establishment of the woody vegetation. This was followed by a gradual
recovery of soil fertility through the process of organic matter cycling. The
colonisation of the herb layer by Andropogon gayanus var. bisquamulatus (typical Sudanian species) during the third state can be seen as an indication
of a substantial return to soil fertility. |
| Mots clés |
Vegetation recovery, Organic matter, Biosphere Reserve,
Pendjari, Benin |
| Pages |
181 - 189 |
| Fichier |
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