How to identify 1500 Lagerstroemia indica in Emei Mountain?

Tree-ring chronology of Lagerstroemia indica in Emei Mountain 1500 was studied. According to the relevant public information, to identify the age of Lagerstroemia indica in 1500 Emei Mountain, it is necessary to collect tree ring samples, observe the characteristics of tree ring shape and color through a microscope, and calculate the growth age of the tree according to the number and morphological characteristics of tree rings.