Zebaze D., Fayolle A., Daïnou K., Libalah M., Droissart V., Sonké B., Doucet J.L. [2021] Land use has little influence on the soil seed bank in a central African moist forest. Biotropica, 1-13. DOI: 10.1111/btp.13032

Regeneration of tropical forest occurs naturally and mainly through early secondary succession by soil seed banks. Here, we analyzed seed bank variation in density anddiversity along a degradation gradient. We also explored the relationship (similarity incomposition) between the seed and seedling banks and the overstory vegetation. The investigated forests were located at Dja Fauna Reserve and its surroundings, south-easternCameroon. We sampled 33 one-haforest plots scattered in a protected area,in a logging concession and in community forests. Within each plot, we inventoriedthe seed bank in the litter and in four successive soil layers of 5 cm depth interval, andthe standing vegetation. Seed density significantly varied with sampling depth but not between land use types. A total of 181 morphospecies were identified. Trees species accounted for 46% of seeds with pioneer species dispersed by animals dominating the seed bank. Species diversity and composition strongly varied with the sampling depth; the litter seed bank was more similar in composition to the soil seed bank than to the seedling bank, sapling, and forest stands. We highlighted the presence of a dense and diverse seed bank in each land use type. We also showed the differentiation of each sampling depth in terms of species composition, thus revealing their complementarity in the dynamics of natural regeneration. The dominance of pioneers in the seed bank and weak relationship with the overstory are universal for tropical forests and logically follow from forest succession after disturbance.

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