The selection of the tolerance drought superior families of pulpwood of Alnus cremastogyne

There was obvious difference in the survival rates of afforestation of Alnus cremastogyne,the amplitude of survival rates of the families in same year was from 50% to 100%,and the average survival rates was 78.1%.The survival rates of afforestation of Alnus cremastogyne in second year was from 52% to 100%,and the average survival rates was 73.7%.The results of the variance analysis of the height growth volume of the two-year old families showed that there were obvious differences in the three levels of families.The superior families such as Betula Luminifera,No.19,No.6,No.4,No.24,No.10 and No.18 were selected from the examination,which the height more than the average examination data (1.60 m),and the survival rates more than the average examination data(73.7%). The best superior family No.19's height was 1.73 m,and the survival rates in the second year was 100%.For afforestation in the drought area,we should select the tolerance drought superior families of Alnus cremastogyne or Betula Luminifera.