Effects Of Latitude And Disturbance Patterns On Soil Physicochemical Properties Of Betula Platyphylla Secondary Forest In The Greater Khingan Mountains

The same forest in different latitude there was some difference of soil physical and chemical properties,fire disturbance,and human disturbance etc.Will cause the change of forest soil nutrient status,makes the soil physical and chemical properties affected by different degree,thus to explore the different latitude and interference of the birch forest soil physical and chemical properties,and the relationship between soil physical and chemical properties,It is of great significance to tending,renewing,protecting and vegetation restoration of Betula platyphylla secondary forest in Daxing ’anling.In this thesis,the soil of Betula platyphylla secondary forest with different latitude gradients(47°N,50°N,53°N)and different disturbance modes(fire disturbance,artificial strip modification disturbance,logging disturbance)were studied.According to the equidistant sampling,Betula platyphylla secondary forest sampling plots were set up in Alshan city(47°N),Genhe City(50°N)and Mohe City(53°N)according to different latitude gradients.At the same time,according to the typical sample selection method,the standard plot of birch secondary forest was set up in three disturbance modes(fire disturbance,artificial strip modification disturbance,cutting disturbance)in Genhe.The physical and chemical properties of soil in Betula platyphylla secondary forest in Daxing ’anling were compared.The results show that:(1)There were significant differences in soil physical and chemical properties of Betula platyphylla secondary forests at different latitudes.The index of soil nutrients decreased from low latitude to high latitude,and soil acidity increased gradually from low latitude to high latitude.The proportion of soil large particle size decreased from low latitude to high latitude,while the proportion of soil small particle size increased from low latitude to high latitude.(2)There were significant differences in soil physical and chemical properties of Betula platyphylla secondary forest under different disturbance modes.The mean values of soil p H,total porosity,organic carbon,total nitrogen,total phosphorus,total potassium,available phosphorus and available potassium were the highest in the secondary forest of Betula platyphylla under artificial strip modification,while the bulk density was the highest in the secondary forest of Betula platyphylla disturbed by fire,and the soil water content and available nitrogen content were the highest in the secondary forest of Betula platyphylla disturbed by logging.(3)Pearson correlation analysis showed that correlations of soil physical and chemical properties were different in Betula platyphylla secondary forest under different latitude and disturbance modes.The results showed that the soil comprehensive index of Betula platyphylla secondary forest in Mohe city was higher than that in Arshan city,and the soil comprehensive index of Betula platyphylla secondary forest was lower than that in Mohe city.The soil composite index of the secondary forest disturbed by artificial strip modification was higher than that of the secondary forest disturbed by fire.