马克思的“超额利润”和“级差地租”理论不仅为我们评价人工林直接经济效能提供了理论依据,而且使我们能够把评价直接经济效能与生态经济效能的内容联系在一起,组成评价人工林经济效能的指标体系和计量系统,实现对人工林经济效能评价的系统化。鉴于目前苏联、美国、日本及其它一些国家对森林经济效能的研究状况,及我国部分 Marx’s theory of “excess profits” and “differential rent” not only provide a theoretical basis for us to evaluate the direct economic efficiency of plantations, but also enable us to link the evaluation of direct economic efficiency with the contents of eco-economic efficiency to form an economic evaluation system for plantations Efficiency indicator system and measurement system to achieve systematic evaluation of economic efficiency of plantations. In view of the present state of research on the economic efficiency of forests in the Soviet Union, the United States, Japan and some other countries,