Authors:
Chauvelin Douh*, Pierre Mbete , Saint Fedriche Ndzaï , Felix Koubouana ,Congo
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Abstract:
The soil seed banks play a crucial role in the resilience of forests to disturbance. Sampling
strategies are generally limited to the first 10 or 15 centimetres of the soil while deeper layers
could conceal specific taxa. This study evaluates the variability of the seed bank as a function of
depth or type of soil in two rainforests in the Congo. At each study site, 30 samples were taken
per soil layer (litter, 0-5 cm, 5-10 cm and 10-20 cm). The diversity and abundance of the seeds
were estimated after they were brought to germination. Two means of estimating the species
richness and the rarefaction curves were used in order to estimate the diversity of the flora in
each layer of soil. The results showed great variability between types of forest. They also
highlighted greater diversity and higher abundance in the first 10 centimetres of soil. However,
the proportions were nonetheless not negligible between 10 and 20 cm, and 21 % of plant species
were encountered exclusively in this layer. The latter may therefore have a fundamental role in
the resilience of forests to anthropogenic disturbances, including logging. Complementary
studies are indispensable in order to better understand this role as well as the factors which have
an effect on the temporal and spatial variability of the soil seed bank |
