合理施肥促进树木生长,但研究发现过多的施用氮肥在北方林区易遭受雪害,这一点应引起各方面的注意。加拿大林学家弗兰克·施奈肯伯格等人在安大略省图恩德贝附近,对12年生松林在12个小区进行施肥试验,每公顷施磷肥100公斤,施钾肥100公斤,施氮肥400公斤。施肥后的林地,经对照比较发现,施氮肥的试验区雪害相当严重(见表)。疏伐虽然可以减少每公顷受害木总株数,但对单株树受害 Reasonable fertilization promotes the growth of trees, but the study found that excessive application of nitrogen fertilizer is vulnerable to snow damage in northern forest areas, which should arouse the attention of all parties. Canadian forestryist Frank Schneikenberg et al. Conducted a fertilization experiment on 12-year-old pine forests in 12 plots near Tuendebei, Ontario, applying 100 kg of phosphate fertilizer per hectare, 100 kg of potassium fertilizer and 400 kg of nitrogen fertilizer. After fertilization of woodland, the comparison found that nitrogen fertilizer in the pilot area of ​​snow damage is quite serious (see table). Although thinning can reduce the total number of trees harvested per hectare, it harms individual trees