Study on the Growth of Old Larix leptolepis Stands in Mountainous Regions of Eastern Liaoning Province

Liaoning province is one of areas with a long history of introduction of Larix leptolepis Gordon and is the largest area of L.leptolepis plantation in China.Production of the short rotation and small dimension wood was the major way of management of L.leptolepis for a long time,as the result,over 60-year-old L.leptolepis stands were seldom to the seen.In recent years,much L.leptolepis plantation were defined as commonweal forest accordiy to classified forest management,therefore,a few L.leptolepis stands would be given up the way of short rotation and be selected the way of long rotation.However,now the management experience of long rotation were absent in China.This paper analyzed the growth characteristics of tree and stand of old L.leptolepis remained in mountainous regions of east Liaoning Province.The results showed that the rate of large dimension wood with diameter at breast height over 30 cm accounted for 90% in 60～86-year-old L.leptolepis stands,and current annual increment of diameter at breast height stayed high growth in all investigated stands and the Percentage Growth Change of diameter at breast height were obvious after thinning.Compared with the original region of L.leptolepis,Nagano-ken in Japan,the growth of tree and diameter at breast height had not difference.According to the management standard of long rotation of L.leptolepis in Japan,the stand which had much growth potential could be cultivated to its fixed number of year with big extent and put long management into practice.