Sustainable Agroforestry-system basing on the Mountain Livestock Production

本研究的重点是结缕草型草地的功能，因为结缕草是最适合实现可持续农林系统的草地。选择三北作为试验田，进行了土壤科学化、生态化和经济性的研究。主要研究结果如下：1)土壤分析结果：复垦结缕草型草地土壤结构不够发达。然而，经过20年，土壤物理环境得到了很大的改善，即土壤表面的根垫发育良好，20 cm深度的土壤层坚硬。随后，一种颗粒状结构被开发出来，在透水性、排水性和保湿性方面有了很大的改善。2)生态分析结果：结缕草型草地保护了红皮书中所列白头翁和日本杜鹃等植物，具有恢复生物多样性的作用。草原就像水田一样，也为游人创造了舒适的景观和便利。3)经济分析结果：首先采用“旅行成本条件价值法”，估算了三别山有无结缕草型草原的景观价值。其次，从数值的差异出发，估算结缕草型草地的价值。价值约410亿日元。草原是非常宝贵的。解决结缕草共有权问题，建立包括中央政府在内的新的支持体系，鼓励结缕草草原的发展。

This study focuses on functions of Zoysia-type grassland, because the grassland is the most suitable for realization of sustainable agraforestry-system.Mt. Sanbe is chosen as a field, and soil scientific, ecological and economic approach have been done. The main results are as followings ;1) The result of soil analysis : On the reclaimed Zoysia-type grassland, the soil structure was not enough developed. However, after 20 years, soil physical environment was improved greatly, i.e., well developed root mat on the soil surface and hard pan layer at the depth of 20 cm. Subsequently, a granular structure was developed which caused a great improvement in water permeability, drainage, and moisture retention.2) The result of ecological analysis : Zoysia-type grasslands conserve Pulsatilla cernua and Rhododendron japonica etc.listed in the Red Book and can recover biodiversity. The grasslands, just like paddy field, also create the comfortable landscape and amenity for visiting people.3) The result of economic analysis : first by using "Contingent Valuation Method by Travel Cost, " the value of the landscape of Mt.Sanbe with and without Zoysia-type grasslands is estimated. Second from the difference of the values, the value of Zoysia-type grassland is estimated. The value is about 41.0 billions yen. The grassland is very valuable. The troubles due to the right of common have to be resolved and new supporting system including central government should be constructed for encouraging the development of Zoysia japonica grassland.