森林是陆地生态系统的主体,是陆地上面积最大、结构最复杂、生物量最多、初级生产力最高的生态系统,在国民经济中占有重要地位,它不仅能提供国家建设和人民生活所需的木材及林副产品,而且还肩负着释放氧气、调节气候、涵养水源、保持水土、防风固 As the main body of terrestrial ecosystem, it is the largest land area, the most complex structure, the most abundant biomass and the highest primary productivity. It occupies an important position in the national economy. It not only provides the timber for national construction and people’s life And forest by-products, but also shoulder the release of oxygen, climate regulation, conservation of water sources, to maintain soil and water, wind-solid