西北杨2号

根据《中华人民共和国种子法》第十九条的规定，由国家林业和草原局林木品种审定委员会审定通过和认定通过的林木品种, 自公告发布之日起，这些品种在林业生产中可以作为林木良种使用，并在本公告规定的适宜种植范围内推广。通过认定的林木良种，认定期满后不得作为良种继续使用，应重新进行林木品种审定。

Pursuant to Article 19 of the Seed Law of the People's Republic of China, forest tree varieties that have passed both official examination and approval and recognition by the National Forest Variety Approval Committee under the National Forestry and Grassland Administration may be used as certified forest tree improved varieties in forestry production from the date of the announcement's release, and shall be promoted within the suitable planting areas stipulated in this announcement. For such recognized certified forest tree improved varieties, they shall no longer be used as improved varieties upon the expiration of their recognition period, and shall undergo the forest tree variety examination and approval procedure again.