众所周知,三大硬阔和椴树在建筑、国防和医药等行业中的用途是相当广泛的。但是,长期以来,随着天然林的大面积采伐和人为破坏,其自然资源急剧减少,而其人工林,由于存在技术等多方面的原因,没有得到应有的重视和发展。 As we all know, the three hardwoods and lime trees have a wide range of uses in the fields of construction, defense and medicine. However, for a long time, natural resources have been drastically reduced with the large-scale harvesting and vandalism of natural forests. However, their plantations have not received the due attention and development due to the existence of technologies and other reasons.