经过18年的持续试验研究表明：北京杨大行距丰产林2×6m、3×6m、4×6m、5×7m密度18年生单位面积材积比对照密度2×2m，分别可提高312．0％、232．3％、220．5％、245．5％，且木材规格高，单位材积的价值量也高于对照。同时随着造林密度的不同，丰产林生产不同材种的工艺成熟龄也有显著差异。以生产大径材为目的，在集约经营条件下，高寒地区大行距营造北京杨速生丰产林有较大前途。 After 18 years of continuous pilot study, the results showed that the annual density of 2 × 6m, 3 × 6m, 4 × 6m and 5 × 7m density of Yangding, Beijing increased by 312.0% , 232.3%, 220.5% and 245.5%, respectively, and the timber specifications are high, and the volume value per unit volume is also higher than that of the control. At the same time, with the different densities of afforestation, the mature maturation ages of different wood species in high yielding forest also have significant differences. To produce large-diameter timber for the purpose, under intensive management conditions, the alpine region to create a Beijing poplar fast growing high yield forest has a greater future.