Natural forests of the clay plain of Sudan are continuously decreasing for various reasons including horizontal expansion on cultivation of crops, cutting for fuelwood and grazing. Then, it becomes more important to mobilize the soil seed bank to restore or reforest the vast cleared areas. Therefore, study was carried out to provide some information on the impact of fire burning on the soil seed bank of the dominant tree species in central clay plain of the Sudan, the Acacia seyal, which is frequently devastated by fire.

Seeds of A. seyal with 89% viability were scattered on the soil surface and buried at depths of 5 cm, 10 cm in plots of 1 m². Each plot was mattresses with dry grass biomass of 0.5, 1.0 and 1.5 kg/m² to generate fire of various intensities and residence time. The seeds were dug subsequent to firing to count the recovered ones and test their viability; the lost and charred seeds were also counted.

The percentage of the recovered seeds in the buried plots (71%) was significantly less than those in unburied ones (79%). However, the differences between the plots of various fire intensities were not significant. The germination of all recovered seeds did not exceed 53%, and this percentage decreased as the fire intensity increased. The viability of the recovered seeds decreased from 89% initially to 55% after burning. The percentage of perished seeds was counted as 5% including both the lost (3%) and the charred seeds (2%).