The Impacts On Soil Properties And Revegetation From Forest Fire In Tahe Forest Region

Some technologies such as Remote Sensing, Geographic Information System and mathematical statistical methods were used in this paper. The fire area distribution map of Tahe forestry bureau in the past 30 years were plotted based on the fire base data from 1974 to 2004. The relationship between influence factors and forest fire was analyzed according to the overlay of fire distribution map and different thematic map. The vegetation regeneration and physical and chemical characteristics variety of soil was also studied in the fire area after the fire of different intension and time interval in different forest type to select proper forest recovery mode according to different cultivation goal, shorten recovery time and improve forest recovery quality.The time factor is the main effect of forest fire that can affect soil moisture content, bulk density and porosity significantly. There no obvious rules of soil moisture and porosity affected by fire intension. The data indicates that fire can make soil structure more tightened.Severely burning can promote the increasing of soil organic matter, available phosphor and hydrolysable nitrogen. But available phosphor decreased with the process of time. There is no obvious rule for soil available potassium. Moderate burning is benefit for the increasing of total nitrogen. Lightly and moderate burning can reduce the soil hydrolysable nitrogen and increase the available potassium. The Cu, Zn, Fe, Mn in soil of the burned area after different time interval and fire intensity have no obvious rules. But the Cu in soil is related with the Fe in soil. They have similar variety tendency in different fire interval and fire intensity.The regeneration degree is different in different forest type, Ass·Herbage-Larix gmelini forest is highest and Ass·Rhododendron dauricum-Pinussylvestrisvar mongolica is lowest. Fire intensity can affect the regeneration of different tree species. The broadleaved forest of birth and poplar appeared in most severely burned area. In the moderately burned area the broadleaved forest of birth and poplar was firstly formed and gradually evolved to mixed forest of coniferous and broadleaved. Lightly burning is benefit for the regeneration of coniferous.The effect of fire intensity on plant type is different in different forest type. The plant type number has no difference among the burned area suffered by different fire intensity in Ass.Rhododendron dauricum-Larix gmelini forest but in Larix gmelini-Populus and slope-Larix gmelini forest, the plant type number increased obviously after the fire. The coverage of arbor and shrub in all forest increase gradually, but herbage coverage decrease after the fire. With the increase of fire intensity, the ratio of high-frequency plant and the equality of plant distribution decreased. Different plant regeneration mode selection should be adopted in different burned area. Artificial sapling regeneration should be performed in the area with good management and site conditions. In the area with poor management conditions and large burned area, the forest regeneration mainly depends on the natural regeneration.The environment in conifer forest has no obvious difference after lightly burning. Its natural regeneration is poor in moderately burned area and broad-leaved species will account for a large ratio after long recovery. The forest in high burned area should increase artificial approach to promote nature regeneration to shorten plant recovery time.According to the characteristic of 5 main forest type in the burned area of Tahe forest bureau, this paper analyzes the variance of plant and soil property of different forest after the fires with different intensity, puts forward relevant regeneration measure and technique.The actuality investigation of artificial regeneration on the burned area of Larix gmelini and Pinussylvestrisvar mongolica indicates that artificial regeneration has obviously effect on the rebuilding of soil structure and plant conditions and has shorter plant recovery time compared with nature regeneration. This paper puts forward the artificial technique of burned area in Tahe forestry bureau according to different cultivation goals of merchandise forest and ecology-benefit forest. It also puts forward 4 artificial regeneration modes for the 2 tree species.This paper can perfect the theory of fire time and space distribution, the effect of fire on plant recovery and soil environment. It also can provide scientific basis for determining reasonable and effective forest recovery mode, quickening up the recovery of destroyed forest, and establishing effective forest management measure.