Introduction of Pinus ponderosa and Pinus banksiana

On the base of introducing seeds of Pinus ponderosa and Pinus banksiana, nursing and planting trial stands, its eco biological characters have been surveying during the period of trial. The results of trial for 5 years indicates: Pinus ponderosa and Pinus banksiana have strong adaptability and stable grow in Longnan distract of Gansu. The average height of 5 year Pinus ponderosa and Pinus banksiana are 0.24 m and 0.42 m respectively, and the average ground diameter are 0.65 cm and 0.71 cm respectively .The present average height growth of 5 year Pinus banksiana (10.51 cm) is higher than that of Pinus tobulaeformis (7.58 cm) , present ground diameter growth of the former is near to the later.