Relationship Between Radial Growth Of Spruce-fir-Korean Pine Forest And NDVI In Xiaoxing'an Mountains

Normalized Difference Vegetation Index(NDVI)has been widely used in the calculation of Net Primary Productivity of ecosystem,but its time series is too short to meet the research requirements of long time series.The relationship between radial growth and canopy growth can remedy for this shortcoming.We analyzed relationship between tree-ring standard chronology of Danqinghe Forest Farm.Yuejin Forest Farm and Tongzigou Forest Farm and GIMMS NDVI and MODIS NDVI based on dendrochronology method in Xiaoxing,an Mountains.The results showed that the significant correlation between radial growth of Pinus koraiensis and annual maximum MODIS NDVI at Danqinghe sampling site and Tongzigou sampling site,the negatively correlation between radial growth of Picea koraiensis and annual maximum MODIS NDVI;the growth trend of vegetation canopy in three regions showed an upward trend;that is the reason for the better relationship between the radial growth of Pinus koraiensis in Danqinghe sampling site and Tongzigou sampling site and canopy growth.Growth decline of the growth of Picea koraiensis at Yuejin sampling point causes a negative correlation with vegetation canopy.With the expansion of the range of MODIS NDVL the correlation coefficient between the radial growth and vegetation canopy reaches the highest value,and then tends to steady or slow down,and When a certain range is reached,in addition,the relationship between radial growth of dominant tree species and MODIS NDVI is better than that of regional tree species.The analysis between radial growth and GIMMS NDVI showed that the correlation coefficient between different tree species radial growth and GIMMS NDVI in Danqinghe Forest Farm is better than that in Yuejin Forest Farm and Tongzigou Forest Farm;and the correlation between the synthesis chronology and GIMMS NDVI was higher than that of single tree species in Danqinghe sample plot,and reconstruction July GIMMS NDVI since 1897 based on consistency between regional tree species radial growth and annual maximum GIMMS NDVI and climatic factors.The low value period of reconstructed GIMMS NDVI sequence corresponds basically to the drought record in this area,drought is the main cause of GIMMS NDVI low value period.In addition,deforestation,forest fire and other factors may also be one of the reasons for the low GIMMS NDVI value.The correlation between radial growing and two kids of NDVI is quite different,the main reasons for this difference that NDVI resolution is different and sensors have different data processing methods.In Xiaoxing'an Mountains,MODIS NDVI may contain more radial growth information of dominant tree species,so it is better to use dominant tree species as proxy index of MODIS NDVI,but it has scope limitation.GIMMS NDVI may contain more regional vegetation growth information,therefor using synthesis chronology agent GIMMS NDVI may be better than single tree species chronology.