森林是一个不断发展的生物群落,森林资源是林业生产的主要生产资料,森林不仅本身具有生产能力,并且具有多种有益效能。随着林业生产经营水平的不断提高,我们不仅要准确地掌握森林资源的现状,而且迫切要求了解森林的动态变化规律,亦即林木的生长、枯亡利用和破坏情况。因此及时准确地掌握森林资源的消长 Forests are a growing community of organisms. Forest resources are the main means of production in forestry. Forests are not only productive in their own right, they have many beneficial properties. With the continuous improvement of the level of forestry production and management, we must not only accurately grasp the current situation of forest resources, but also urgently need to understand the laws of the dynamic changes of forests, that is, the growth, destruction, utilization and destruction of trees. Therefore timely and accurate grasp of the growth and decline of forest resources