Fire Disturbance To TaHe Forest Soil Microbes And Enzyme Activity

Fire is the dominant natural disturbance in China’s boreal forest,which affect the maintenance and succession of forest ecosystem.It affect the forest ecosystem is not only reflected in the biological part on the ground, but also in the underground soil ecosystem. As the results of this study, the fire interferen effect forest soil ecosystem obviously and have important influence on the soil microbes, enzyme activity,soil physical and chemical properties.Fire Interference can cause the change of forest soil physical, chemical and biological characteristics.Soil microbes, soil enzyme activity and soil nutrient content is the important measure of soil conditions,so the investigation of them is good for Assessment of soil degradation degree after fire and have great significance for understanding the law forest ecosystem and reasonable for forest fire management.To find the law of fire disturbance on forest ecosystem,we research the change of the real-time and short-term interference effect of fire on soil microorganism, enzyme activity and soil physical and chemical properties in birch larch and mongolica forest ecological system through the burning experiment and post-fire soil survey method. For the more we delve into the relationship between the micro topography and disturbance degree of each fire intensity. In the comprehensive analysis of fire disturbance on soil microorganism, enzyme activity, and changes of soil physical and chemical properties after fire disturbance, this paper can draw the following conclusion:(1) Fire has interference effect on soil microbes, soil enzyme activity and soil physical and chemical properties in birch-larch and mongolica forestry,the degree of disturbance influenced by fire intensity and the micro topography. This study results show that soil microbial properties often show significant difference after the different disturbance and fire intensity has important effects on the degree of disturbance intensity, which is the decision key factor of the disturbance degree.(2) Fire intensity not only affect the change range of soil microorganism, enzyme activity and the physical and chemical properties but also decide the direction of change. Low intensity fire has positive effect on soil microbial community,which increasing content of microbe, improving the level of metabolic activity and diversity.High intensity fire decrease soil microbial, metabolic activity and diversity. Secondary intensity fire influence effects due to the forest style.(3) Forest style effect the disturbance degree of different fire intensity interference Under the same intensity, there are different change range and direction of the soil microorganisms in different forest type. Variance analysis also showed that the difference of soil microorganism, enzyme activity,the physical and chemical properties are different on different forest style, on different intensity fire disturbance.(4) Micro topography have influence on soil microorganisms and fire behavior, therefore interfere with fire on forest soil microbial closely linked.There are similar effect of fire interference on soil microbial on east and west slopes.(5) Burn experiments show that the fire can be caused the change of soil microorganism, enzyme activity in a short period of time,which results in the decrease of soil microbial content and total metabolic ability level,and the activity of soil phosphatase, catalase、invertase and urinary enzyme decreased too. The instant change degree of the soil microorganism, enzyme activity and physical and chemical properties after the fire is linkes closely with the average and highest soil temperature.(6) There are significant correlation between the content of soil microbial metabolism and community levels. In post fire forestr, physical and chemical properties and soil microbes, enzyme activity are mutual influence.