前几年,听到这样一个传闻,说是有的林业单位在规划中提出本世纪末森林资源翻一番。我们姑且不去理会消息准确与否,而资源增长是涉及林业现代化的重大问题,这恐怕不会有异议。很明显,森林资源增长的实质所在是净增量(后期与前期的资源数字之差)为正值。在一定期间内,净增量越大,表明资源增长得越多。反过来说,采伐量大于生长量,或自然灾害严重,亦或经营不合理,致使后期的资源数字小于前期,也就是说,出现了负生长,净增量变为负值。结果是资源变化呈现减少的趋势。为了便于说明问题,我们仿照生长率的形式,将净增量改换为净增率。具体说,净增率就 A few years ago, I heard such a rumor that some forestry organizations have proposed in the plan that the forest resources will double by the end of this century. Let us not ignore whether the news is accurate or not, and that the growth of resources is a major issue concerning forestry modernization. I am afraid there will be no objection. It is clear that the essence of forest resources growth is the net increase (the difference between the resources in the later and previous periods) is positive. In a certain period of time, the larger the net increment, the more resources have been increased. Conversely, the amount of logging is greater than the amount of growth, or serious natural disasters, or unreasonable operation, resulting in the latter part of the number of resources is less than the previous period, that is, there has been negative growth, the net increase becomes negative. The result is a decreasing trend in resource changes. In order to illustrate the problem, we have modeled the growth rate and converted the net increase to a net increase. Specifically, the net increase rate