The Research Of The Soil Physic-chemical Properties And Fine Root In Burned Areas Of Huzhong And Nanwenghe Conservation

The effect of fire to ecosystem is big and complex, not only reducing the biomass on the ground, also changing the soil layer physicochemical property, micro-biological degradation and growth of fine root. Fire may be harm or helpful to the soil, it depends on the intensity. Usually, high-intensity fire leads to the succession of plant community, degeneration of soil composition, changing of hydrology function, organic substances content in soil, ratio of C/N, and result in subsequent nutrient loss through accelerated erosion, leching or denitrification, changing of microorganism, numbers of animals underground and process of their activity relevant.This article is emphasis on the effect of different intensity of fire to soil physical, chemical property and fine root biomass, in larch forest and white birch forest, in Greater Higgnan Mountains Hu Zhong Nature Reserve and Nan Wong River Nature Reserve.Different forest types have different volume weight of soil, PH, organic matter, total N, effective N, total P and total K. The law is that, volume weight and total P of soil in A layer in larch forest is greater than that in white birch forest, total P in B layer is not clear. Total K in layer B or b soil in white birch forest is greater than that in larch forest in Nan Wong River primitive forest, except this area, it's opposite in the same fire condition, it's not clear in soil A or a layer. The PH, organic matter, total N and effective N in larch forest A layer is less than that in white birch forest, and layer B is not clear. In both areas, volume weight of soil, PH, organic matter, total N and effective N in layer A or a in larch and white birch forest are greater than that in layer B or b. Except Nan Wong River Nature Reserve, total P in layer A or a is greater than that in layer B or b. The total K in layer A or a in both areas is less than that in layer B or b.The law of affection of different intensity of fire on volume weight of soil, PH, organic matter, total N, effective N, total P and total K is as follows. In both areas, the volume weight of soil in different fired areas from big to small is moderate fired area, primitive area and severe area. PH is increasing with fired intensity from primitive forest to moderate fired forest and then severe fired forest, while organic matter and effective N is decreasing with greater fired. In Hu Zhong Nature Reserve, total P in layer A or a in larch forest and white birch forest from big to small is primitive forest, severe fired forest and moderate fired forest. In Nan Wong River Nature Reserve, total P in layer A or a in larch forest and white birch forest soil from big to small is moderate fired forest, primitive forest and severe fired forest, while fire intensity has not obvious order to the content of total K in soil.In both areas, in the same fire intensity and forest types, the volume weight of soil in Hu Zhong Nature Reserve is inferior to Nan Wong River Nature Reserve, but organic matter, total N, and effective N is opposite. While PH, total P and total K in soil have not clear order in both areas.There is not clear order in both types of forests with the same fired intensity on soil moisture content. Because there are many reasons can be effective, for example, rainfall, plant types, canopy density, and topographic condition and so on. But soil moisture content in Hu Zhong Nature Reserve is higher, may be for it's almost a wetland forest-island.In both areas, the fine root biomass has not a clear order in eight directions. But from 1 mile to 3 mile, it's decreasing.