六年前我们和福建来舟林业试验场等单位协作,开展珍稀优良树种的引种试验,建立了三处珍稀树木园,筛选出以长序榆为首的一批有发展前途的针阔叶树种。研究成果已于1990年底通过林业部主持的专家鉴定,1991年被林业部批准列项,由我校负责进一步推广。长序榆不同于白榆或榔榆,是近年来发现的新树种,树干端直,生长较快,材质优良,可与榉树 Six years ago, we cooperated with units such as Fujian Libo Forestry Experiment Station to carry out the introduction test of rare and fine tree species, established three rare arboretums, and screened a group of promising coniferous and deciduous tree species headed by long-eared elm. The research results were appraised by experts presided over by the Ministry of Forestry at the end of 1990 and listed by the Ministry of Forestry in 1991, which is further promoted by our school. Long-cut elm is different from elm or elm, is a new species found in recent years, trunk straight, rapid growth, good material, with the beech tree