三、森林生态系统的生产力各种森林生态系统的生产力由于所处环境条件、年龄阶段及经营集约程度等不同,存在很大差别。由大范围来看,森林生态系统中以热带雨林的净第一性生产力和生物量为最高,随着热量的减少而渐次减少,以北方针叶林为最低。根据日本、欧美对大量森林生态系统的生产力的调查,亦可得出类似的结论(表5),森林生态系统的净第一性生产力明显地受热量 Third, the productivity of forest ecosystems The productivity of various forest ecosystems is very different due to the different environmental conditions, age stages and operating intensities. On a large scale, the net primary productivity and biomass of tropical rain forest in forest ecosystem are the highest, with the decrease of calories decreasing gradually, with the lowest in the northern coniferous forest. A similar conclusion can be drawn from the surveys of the productivity of a large number of forest ecosystems in Japan, Europe and the United States (Table 5). The net primary productivity of forest ecosystems is clearly affected by heat