GEOGRAPHIC VARIATION OF COLD HARDINESS OF PINUS ARMANDI

This paper deals with the results of a series provenance trials of Pinus armandi at 11 locations. The overwintering characteristics of the seedlings at the age of 1-3 years in the nurseries and frost resistance of young trees in the field were investigated. It was found that virtually all seedlings of the 11 Yun-gui Plateau provenances had died in the northern portion of its range and heavy mortality and dieback of trees occurred during the 4-8 years in the field in the central portion of China. These data clearly indicated that cold hardiness of southern provenances was very weak. In contrast to these, no provenances come from the Daba-Qinling Mountains were lost from the frost. A strong relationship between latitude of seed origin and mortality as well as frost damage was found with correlation coefficient R=0.794**.