Age Structure and Dynamic Characteristics of Malus sieversii in Emin County

Typical sample plot survey method was adopted in the concentrated distribution area of Malus sieversii in Emin County, Tacheng area to make the diameter class structure replace the age structure, and combined with the population ecology correlation analysis method to study the age structure and dynamic change characteristics of the Malus sieversii population. The results show that the age structure of M. sieversii presents an atypical pyramid with extremely wide base and narrow top, the quantitative change dynamic index V'_pi of population structure considering external interference is much smaller than that ignoring external interference, but greater than 0, sensitivity index P_max of population structure to random disturbance is close to 0, it shows that the population belongs to growth type, but it is sensitive to external interference, the survival curve model tends to be Deevey-Ⅱ type. In the next 40, 60 and 80 years, the number of individuals in age class young is declining, and the number of individuals in age class middle and old is continuously supplemented, indicating that it is difficult for the population to maintain long-term stability. Therefore, in the future, it is necessary to strengthen the care management and artificial maintenance of M. sieversii seedlings and existing individuals in order to promote the stable growth of the populations and resource recovery.