四川马尾松低产林经营类型划分及其应用研究(Ⅱ)──典型低产林经营类型改造试验

在划分了四川马尾松低产林经营类型的基础上，选择了乐山市洪雅、青神和眉山三个县进行以采伐更新为主的低产林改造技术措施研究，总结出了8个低产林经营类型的最佳改造技术组合。分析了调整林种结构，发展经济林在低改中的重要意义。试验表明幼林阶段适当地间种农作物有助于林地土壤改良和提高林分生长量。试验和调查结果还表明封山育林对于保持水土、保护现有林分不受破坏具有重要作用。但在提高林分产量方面有较大的局限性。因此建议对于以用材为主要目的的林分，在有条件的情况下，应尽可能采取全砍重造的改造方式。

THE CLASSIFICATION AND THE APPLICATION OF LOWER PRODUCTIVE MASSON'S PINE STANDS IN SICHUAN (Ⅱ) ──Reformation Experiment of Typical Working Groups of Lower Productive Masson's Pine Stands

Three counties in Leshan District were selected for reformation experiment after classfication of lower productive masson's pine stands. The best reformation measures for eight main working groups of lower productive stands were summerized. The Significance of forest species regulation and non- timder (or economic) forest development are discussed. Experiment results show that intercropping in yong masson's pine plantation can better forest soil and promot tree increment. Ivestigations show that wilderness preservation is necessary to protect forest from disterbance of mankind and domestic animals and reduce soil erosion. But this kind of measure can not make forest grow fast and increase timber production greatly. We suggest that clear cut and reforestation with suitable tree species is the best choice for timber stand reformation.