Possibility of forest reconstitution from soil seed bank of cocoa and rubber farms in eastern Ivory Coast

Abstract

What is the capacity of the soil seed bank to restore floristic diversity when forest disturbance is linked to a perennial crop? To answer this question, the main objective of the present study was to assess the contribution of the soil seed bank of cocoa and rubber farms in the process of forest flora reconstitution. To do this, 432 composite soil samples were first collected from 108 farms, 54 of which were from each of the above-mentioned farms in the Indénié-Djuablin region in eastern Ivory Coast. These samples taken at depths of 0 to 5 cm (n=108 samples), 5 to 10 cm (n=108 samples), 10 to 15 cm (n=108 samples) and 15 to 20 cm (n=108 samples) were then placed in a greenhouse for quantitative and qualitative evaluation of viable seeds. The investigations showed that in cocoa and rubber farms the maximum number of viable seeds that could initiate the process of forest reconstitution after abandonment of the crops is stored in the first five centimeters of the soil. However, this species pool contains very few tree species. Consequently, the seed stock in the soil of cocoa and rubber farms alone cannot effectively reconstitute the forest flora after crop abandonment. It would be interesting to explore other research perspectives such as the contribution of spontaneous flora of these farms in the process of reconstitution of forest flora.