Abstract:
Tow experiments were conducted in Northern Kordofan State during the seasons 2004/2005 and 2005/2006 to investigate the effect of burning and its intensity on soil seed bank in clay and sandy soils. One of the experiments was conducted to investigate the amount of live seeds in the soil (seed bank) in burned and unburned sites in clay and sandy soils. The other experiment was conducted to investigate the impact of fire intensity on live soil seed bank and plant species by using the treatments; no burning as a control, burning with the existing fuel, burning with double existing fuel and burning with triple existing fuel. Completely randomized design with twenty replicates was used. The results of the first experiment showed that the number of live seeds in the soil seed bank was higher in unburned site compared to the burned site. Soil seed bank was significantly higher in clay soil than in sandy soil in both experiments. In the second experiment, the number of live seeds in soil decreased with the increase in burning intensity. Live seeds were higher in the top-soil compared to sub-soil in the two experiments. The plants, Dactyloctenum aegyptium and Ipomea cordofana were not affected by intensity of burning in clay soil. In sandy soil, the densities of Dactyloctenum aegyptium and Cenchrus ciliars decreased with the increase in fire intensity. The densities of Fimbristylis hispidula and Eragrostis tremula increased with the increase in fire intensity in sandy soil. The effect of fire intensity on the density of other species was not consistent, but they ware all reduced at higher intensity.
