Difference Analysis Of Climate Change Of Radix Growth In Betula Platyphylla In Hanshan Secondary Forest Area

This paper takes the main broad-leaved tree species-Betula platyphylla in the Hanshan secondary forest area as the research object.One-hectare plot is set up in the Qingshan National Nature Reserve of Xing'an League and the Huanggangliang Provincial Nature Reserve of Chifeng City.Betula platyphyllatree cores were collected and master standard chronology were estabilished.Then the correlation analysis method was used to study the climate change in the growth of Betula platyphylla in different regions.The main results are as follows:1.The average temperature,average minimum temperature and average maximum temperature are on the rise and summer precipitation shows a downward trend during 1961-2017in Qingshan and Huanggangliang.The temperature factor of Qingshan Research Zone rises faster than Huanggangliang,butthe downward trend of summer precipitation is lower than Huanggangliang.2.Established a Betula platyphylla STD chronology in two regions andcompared the main statistical parameters of the STD chronology in the two regions.The characteristic parameter values of both regions have reached a good level that proof it's available to ecological studies of tree rings.3.In the Qingshan area,the radial growth of Betula platyphylla is affected by extreme temperature and precipitation,but the average temperature effect is not obvious.Precipitation and the average minimum temperature in November have a positive correlation with the radial growth of Betula platyphylla The average maximum temperature in September is the main climatic factor limiting the radial growth of Betula platyphylla.In the Huanggangliang area,the radial growth of Betula platyphylla is mainly determined by the average temperature,average minimum temperature and average maximum temperature of the previous year and the summer of that year(mainly June and July),precipitation has little effect on it.