Spatial Distribution And Influence On Soil Physical And Chemical Properties Of Forest Fire In Tahe Forestry Centre Of Daxing’ An Mountains Region

This research by means of spatial statistical analysis and mathematical model for the study of method, the influence of spatial heterogeneity of different forest fire intensity and different ways of forest fires on soil physical properties and chemical properties in Daxing’an mountains are analysis, and the influence of the spatial heterogeneity of different forest fire intensity and fire way to vegetation restoration and vegetation diversity are analysis, and the theory of frontier model and spatial statistical analysis method are combined, the characteristics and meteorological factors of forest fire stand spatial distribution and forest fire forecast model in Daxing’an mountains are statistic and analysis.In Daxing’an mountains region, Jiagedaqi area is the most times of forest fire area, Songling area is the largest area of forest fire damage area, the higher of fire, the more serious of the damage to the forest land area. The frequency of lighting fire is relatively fewer in all the years in Daxing’an mountains, most of the total number of occurrences is artificial:fire, especially the old fire again of2003in Huma country of Daxing’an mountains led to the woodland area of damage.Tahe area in Talin is the highest number of forest area between1974and2005there were92forest fires, Zhang Ling Forest is the least number of forest fires in the region, only7times. Tahe area Pangu forest is the largest forest fire destroyed areas, lightning fire destroyed an area of20018ha, man-made fire destroyed an area of6937ha, fire destroyed an unknown area reached5421110ha. The number of different levels of forest fires occurred more frequently after2002in Tahe area.The zero inflated model and the fence model was fitted, and the use of AIC, the likelihood ratio test (likelihood ratio test, LR) model and residual sum of squares (SSR) carries on the contrast analysis to the model fitting results, select the best forecasting model from. The results show that the ZINB model of AIC and SSR minimum, the local forest fire and meteorological factors best fitness. In addition, judgment on "assumption0" part according to the fire research to the actual occurrence regularity and different model, zero inflated model is more suitable for forest fire characteristics in Greater Khingan Range area.Whether the application of the "current" or "the year before" meteorological data modeling, multivariate linear model of AIC, BIC, RMSE values were more than Gamma model, Gamma model fitting is better than multiple linear regression model; according to the model of the statistical test and parameter analysis results, the optimal Gamma model fitting level and model meteorological factors significant level are higher than the corresponding Gamma model; the spring rainfall of RF (s), average maximum temperature of MAT (s) against the spring, spring against the average sunshine hours of SH (s), the annual average temperature of TY, fall prevention average lowest temperature MIT (f), more than0.11mm days DA daily precipitation fall prevention (f), fall prevention average relative humidity of RH (f), the forest fire in Tahe area had significant impact area.Soil moisture, soil bulk density and soil porosity in different ways with the increase of forest fires altitude exhibited some regularity:soil moisture decreased with the increasing of altitude, soil bulk density and soil porosity showed with the increase of the altitude and elevation.Without the burning forest, soil organic matter, total nitrogen, available nitrogen and available potassium in the low altitude region (altitude300m-400m) content is minimal; after mild fire, in addition to pH, soil organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus, available potassium are minimum content in low altitude region; after moderate fire, except available K, soil organic matter, pH, total nitrogen, available nitrogen, total phosphorus, available phosphorus content in the low altitude region are also the least; after severe burn, total nitrogen, soil organic matter, pH, available nitrogen, total phosphorus, available phosphorus, available potassium content in low altitude regions are the least, visible, at low altitudes, due to frequent human activities, and the influence of external factors, the content of the nutrient content in soil is obviously less than that of soil nutrient at high altitudes.After mild and moderate after the fire burning, the soil trace elements copper, zinc, iron, manganese in the low altitude region (altitude300m-400m) content is minimal; after severe burn, in the soil of the trace elements copper, zinc, iron, manganese at high altitude (height above sea level is500m-600m) content is the most; in the altitude of300m-400m, both in moderate or severe, mild fire fire fire trace elements in soil are lower than without fire stand, in the altitude region, through the surface fire and underground after the fire, the content of trace elements in soil are higher than without fire stand; at an altitude of more than600m, through the surface after the fire, the content of trace elements in soil are higher than those without the burning forest.The factor scores of elevation and soil nutrient do correlation analysis, was found after the fire, there was a positive correlation between altitude and common factor F2, the correlation coefficient was0.946, the most close relationship with F2for Mn shows that, with the increasing of altitude, exhibited spatial heterogeneity is the most obvious; moderate after the fire, the altitude had significant positive relationship with F1, the correlation coefficient is0.691, the pH value, total nitrogen, available nitrogen, total phosphorus, available phosphorus, zinc, iron, manganese and F1for the relationship, with the increasing of altitude, exhibited spatial heterogeneity is obvious; severe fire, altitude there is a positive correlation between the complete with F1, the correlation coefficient is1, the organic matter, pH, available nitrogen, total phosphorus, zinc, iron, manganese and F1for the relationship, with the increasing of altitude, showed obvious spatial heterogeneity; through the surface after the fire, altitude with F1, F2, F3and F are not obvious correlation, that with the increasing of altitude, all nutrients showed no obvious spatial heterogeneity.After the investigation of different forest fire intensity factor in the spatial distribution of vegetation significant difference. At the altitude of300m-400m, whether it is mild, moderate or severe fire fire fire are conducive to the resumption of vegetation. Height above sea level is greater than or equal to600m, recover the surface fire and underground fire is not conducive to vegetation.After a mild and severe burning fire, the importance value of vegetation, diversity index (Shannon-wiener index) and richness index (Menhinick index) maximum appear in the altitude of500m-600m, the mild and severe burning fire, altitude for recovery of500m-600m is best for vegetation.