Abstract: Taking the Populus euphratica forest in the lower reaches of the Tarim River as the object, three typical sections of the downstream rivers, Yingsu, Kardaiyi and Arakan, were selected to analyze the radial growth of the P. euphratica in the lower of the Tarim River, based on the weather station near the section. The average minimum temperature and extreme low temperature data of long time series were analyzed by correlation analysis method to study the radial growth of P. euphratica in the lower reaches of the Tarim River and the response of the P. euphratica index to the average minimum temperature and extreme low temperature dynamics. The results showed that the radial growth of P. euphratica in three typical samples in the lower reaches of the Tarim River showed a decreasing trend. There was a significant negative correlation between radial growth and temperature of P. euphratica along the rivers in the lower reaches of the Tarim River, and the radial growth of P. euphratica in the Yingsu section was positively correlated with temperature, despite not obvious. The annual growth index of P. euphratica in three sections showed a downward trend and the mid-wheel index of the three samples showed a negative correlation with the average minimum temperature and the extreme minimum temperature.

Key words: Populus euphratica, tree rings, climate change, lower reaches of the Tarim River