However, a decline of Satoyama's economic value due to the increased use of fossil fuels and chemical fertilizers caused gradual changes in the habitat of Satoyama from its original red pine woods (as the red pine is a sun tree, the invasion of other species impedes its further reproduction).
しかし化石燃料や化学肥料の普及によって里山の経済価値が失われると里山の植生はアカマツ林から徐々に変化していった（アカマツは陽樹であるため、他の樹種が侵入してくると次の世代が繁殖出来なくなる）。