Soil Seed Banks Dynamics and Restoration Potential of Some Selected Forest Reserves in Southwest, Nigeria

Abstract

This research investigated the regeneration potential of soil seed-bank along three soil depths in three secondary forest communities within Southwest Nigeria, for a better understanding of the potentials of the soil seed banks in facilitating succession towards a more natural forest of native tree species in International Institute of Tropical Agriculture (IITA) Forest Ibadan, Elephant Forest reserve Omo and Emerald Forest in Ikoyi Nigeria. Eight temporary plots of 20m by 40m using systematic line transect were laid in each forest. Soil samples were taken at three depths of 0–5 cm, 5–10 cm and 10–15cm and the seed bank composition was determined under a greenhouse condition. The results show that IITA forest has an abundance of 93 species with the highest in soil depth of 5-10 (35) and least exists at 10-15cm (24). The species evenness ranged from 0.92 to 0.96, with an average value of 0.94. Emerald forest had a total of 74 tree species with 0-5 cm depth having the highest species abundance (34), while depth of 5-10 cm (21) exhibit the least species abundance. At the forest, results of Species diversity indices show that at 0-5 cm depth 2.47 index value was recorded, a value much higher than what was recorded at 5-10 cm (2.40) and 10-15cm (2.36) respectively. The result of Elephant Forest reserve shows that a total of 87 tree species were recorded with 0-5 cm depth having the highest species abundance (40) followed by 5-10 cm (27), 10-15 (26) respectively. The Shannon Wiener index for Elephant Forest shows that 2.28 were recorded at 0-5 cm depth, 1.40 at 5-10 cm depth, and 1.70 at 10-15cm depth respectively. The soil seed bank could help in determining the status of regeneration potential of the three forests investigated. However, high dominance of tree species in the soil seed banks implies that the forest is disturbed and there is likelihood of tree species succeeding and dominating the forest ecosystem.