在美国,植树节是一个州定节日,没有全国统一规定的日期。但是每年四五月间,美国各州都要组织植树节活动。近代植树节是由美国内布拉斯加州发起的。19世纪以前,内布拉斯加州是一片光秃秃的荒原。那里树木稀少,土地干燥,大风一起,满天黄沙,人民深受其苦。1872年,美国著名农学家朱利叶斯·斯特林·莫尔顿提议在内布拉斯加州规定植树节,动员人民有计划地植树造林。 In the United States, Arbor Day is a state holiday and there is no nationally agreed date. However, April and May each year, the United States should organize Arbor Day activities. The Arbor Day was initiated by Nebraska in the United States. Before the nineteenth century, Nebraska was a bare wasteland. Where the trees are scarce, the land is dry, the gale together, the sky is full of yellow sand, and the people suffer from it. In 1872, the famous American agronomist Julius Stirling Moulton suggested that Arbor Day be arranged in Nebraska to mobilize the people to plan the afforestation.