营林生产在未到采伐阶段时 ,劳动对象是大量尚未成熟的林木资源 ,不能实现其营林收入 ,年度营林生产的成果在实物形态上表现为林木资源在一年内蓄积增长量 ,它的价值形态表现为一种“隐形收入” ,如何对这种“隐形收入”合理地进行计算 ,“预核算”办法有实际应用的意义 In the unforeseen stage of forest production, the target of work is a large amount of forest resources which are not yet mature, and can not realize its revenue from silviculture. The result of annual forest production shows in physical form the accumulation of growth of forest resources in a year. The value of the form of performance as a “hidden income”, how to calculate this “invisible income” reasonably, “pre-accounting” approach has practical significance