Effects of Forest Fire on Cellulolytic Microorganisms in the Soil

ABSTRACT:  The effects for forest fire on the abundance of cellulolytic micro-organisms in the eight soil samples, in burned and unburned plots in lowland deciduous forest on Doi Suthep was investigated. Samples were collected 1, 7 & 30 days after burning, from February to March. The dilution plate method was used for counting the number of micro-organisms on carboxymethyl cellulose agar plates, observing a clear zone after incubating at 28 degrees centigrade for 3-5 days. Seven days after incubation, the number of micro-organisms in soil decreased in both burned and unburned areas and after 30 days, the number of micro-organisms in the soil increased but in the unburned areas the number of micro-organisms in the soil decreased. Soil pH, soil moisture and soil nutrients were determined. Soil pH in the two areas was between 6.1-6.7. In the burned area, soil pH increased seven days after burning. Seven days after burning soil moisture decreased and after 30 days it increased. Soil organic matter nitrogen decreased after burned 3o days. Phosphorus and potassium in the soil increased in the burned area but decreased in unburned area. Relationships between the chemical and physical properties of the soil and micro-organism numbers were statistically insignificant.