Great fluctuation of temperature           

Fire destroys all vegetation as well as the soil animals. Fires can cause a great fluctuation in temperature, the burnt soil gives a black surface which is a good absorber of solar energy. Without any plant cover the soil rapidly gains heat and loses heat.

Water loss                                                                            

As fire can cause temperature to rise, this will increase the water loss by evaporation.

Humus is very important of soil to hold water. After certain humus has burnt away, soil easily loses water by evaporation.      

Slash-and-Burn Deforestation

The deforestation technique of slash and burn, utilized extensively to clear large areas of forest for agricultural and other purposes, causes an enormous amount of environmental damage. The large amounts of carbon dioxide given off into the atmosphere during burning adds to the greenhouse effect. The removal of all trees and groundcover destroys animal habitats and greatly accelerates erosion, adding to the sediment loads of rivers and making seasonal flooding much more severe.

Many fires are set by man, either deliberately or not and because they remove vegetation and expose the ground they tend to lead to increase rates of soil erosion.

The burning of forests, especially in the first year after the first event, lead to a high rate of soil loss. Burnt forest tends to have rates a whole order of magnitude higher than those in protected areas. Comparably large changes in soil erosion rates have been observed to result from the burning of heather and the effects of burning may be felt for the six years or more that may be required to get regeneration of the heather.

The causes of the marked erosion associate with burning are interesting. There is normally a distinctive non-wettable layer in the soil supporting chaparral. This layer, composed of the soil particles coated by hydrophobic substances leached from the shrubs orb their litter is normally associated with the upper part of the soil profile and build up through time in the unburned chaparral. The high temperature which accompany chaparral fires causes these hydrophobic substances to be distilled and they condense on the lower soil layers. This process results in a shallow layer of wettable soil overlying a non-wettable layer. Such a condition, especially on steep slopes, can result in severe surface erosion.