Study On Spatial Distribution Characteristics Of Soil Organic Matter In The Daxing’an Mountains District

As one of the most important indicators in soil,soil organic matter has an irreplaceable position in judging soil quality and managing soil.The purpose of this paper is to discover the spatial distribution of soil organic matter in the Daxing’an Mountains,combine the factors such as topography to explore the influencing factors of organic matter,provide a scientific basis for the sustainable use of land in the Daxing’an Mountains.This paper is based on the measured sample points of soil organic matter in the Daxing’an Mountains,statistical analysis of the data,preliminary analysis of the spatial distribution of organic matter using ordinary Kriging interpolation,secondly,the study of organic matter inversion modeling analysis by remote sensing data,distribution rules of organic matter in the study area through a comprehensive analysis of the two methods,and explore its main influencing factors.The main results:(1)Daxing’an Mountains of surface soil organic matter content 0 ~ 20 cm interval 20.19-208.49g/kg,average of 76.22g/kg,standard deviation of 58.65 g/kg,coefficient of variation is 76.95%,the degree of variation is moderate variability.The original logarithmic transformation after the data is in accordance with the normal distribution,exponential model fits better than other models,block base ratio is 32.78%,the influence of structural factors is greater than the influence of random factors.(2)The relationship between soil organic matter and the spectral reflectance of the Daxing’an Mountains is increasing the length of the reflection band was increased and then decreased tendency,which varies greatly in the 5-7 band.Organic matter content and soil spectral reflectance Daxing’an Mountains region showed a negative correlation,among them,the near-infrared band 5 has the highest correlation,followed by the Band 4 Red and Band 6 SWIR 1.Logarithmic transformation and reciprocal transformation improves significantly,the significance of the first-order differential transformation is not obvious.The modeling effect of multi-band model is better than that of single-band model in model construction,but the fitting effect is not as good as the single band,mixed multi-band and a mathematical transformation can well reflect the information Imagery,and the stability and accuracy of the model are higher than other inversion models.(3)Interpolation show,the distribution of soil organic matter in the Daxing’an Mountains has certain regularity,northwest,the southwest and the lower part of the upper northern region there are three regions with the highest value,organic matter content of northwest region and the southeast relatively low contrast elsewhere.Figure based on the content of organic matter derived inversion model shows that,the overall level of organic matter content in the Daxing’an Mountains is at a rich level of national grading standards,and soil organic matter content higher than the northern part of the study area in southern,most areas with high organic content are concentrated in mountainous areas,low organic matter content is more concentrated in the area of density within the range of ground area,residential areas and farmland and other human activities.(4)The main factor affecting the organic matter content of the Daxing’an Mountains above sea level and pH value,the effect of slope and aspect on organic matter is relatively insignificant.Organic matter content is positively correlated with altitude namely soil organic matter content increases with rising altitude and the increase,organic matter content is negatively correlated with pH namely with the increasing content of organic matter pH value will correspondingly reduce the change of trend;although soil organic matter was positively correlated with the slope value,but a weak correlation,soil organic matter was positively correlated with slope values,but the level was not significant.