Correlation between Quality of Tannin Extract of Quercus variabilis and the Main Ecological Factors
The tannin extract contents in different organs of Quercus variabilis are mainly influenced by ecological factors. In order to understand the principal ecological factors affecting Q. variabilis tannin extract,and to provide scientific cultivation measures of Q. variabilis and an reference for efficient utilization of the tannin extract resources of Q. variabilis,a total of 108 Q. variabilis trees and the major ecological factors were investigated and determined in 6 sample plots of three different distribution regions ( south slope of Qinling Mountains,north slope of Qinling Mountains,Loess Plateau) in September 2012. The tannin content of different organs of Q. variabilis in the 3 different distribution regions (6 sample sites) was analyzed by UV spectrophotometry and the grey correlation degrees with the ecological factors were calculated. The results showed that there was a significant difference in tannin content among the different regions. The tannin content in the 3 different distribution regions from high to low was the south slope of Qinling Mountains,the north slope of Qinling Mountains and the Loess Plateau. The tannin content of Q. variabilis valonea in the 6 regions was highest,followed by the bark,leaf,branch,and the tannin content of root and stem was lowest. The principal soil factors that influenced tannin content of different organs of Q. variabilis were available nitrogen,available phosphorus,and available potassium. Soil organic matter was one the main factors affecting the effective component content of tannin extract of Q. variabilis. There was a positive correlation between tannin content of organs and these main soil factors. The principal climatic factors that affected tannin content of different organs were frost-free periods,annual sunshine hours and annual mean rainfall. The frost-free periods and annual mean rainfall were positively correlated with tannin content in different organs of Q. variabilis,while the annual sunshine hours was negatively correlated with tannin content in different organs of Q. variabilis. The region with longer frost-free periods,more rainfall,shorter sunshine hours,more organic matter and lower soil nutrients content could prior be chosen as cultivation area of Q. variabilis for high tannin production.
国家科技期刊平台
NSTL
万方数据
维普
