北半球有四个主要森林区,每个区都含有许多同属树种,病原真菌同它们的寄主处于平衡关系,共同生活在这些森林中,但它们如果进入另一个区,则可以引起巨大的损失。本文分析的是北半球几种重要森林病害——栗疫病、白松疱锈病、榆枯萎病、松材线虫病。栗疫病在美国东部,由病原真菌寄生内座壳(Endothia parasitica)引起的栗疫病的流行,就是一个引入病原生物迅速和 There are four main forest areas in the northern hemisphere. Each contains many species of the same genus. Pathogenic fungi are in balance with their hosts and live in these forests. However, they can cause huge losses if they enter another area. This article analyzes several important forest diseases in the Northern Hemisphere - chestnut blight, white blister rust, elm blight, and pine wilt disease. The prevalence of chest blight in the eastern United States, caused by the pathogen fungus, Endothia parasitica, is a rapid,