Abstract: Through over 30 year efforts,the forest-covered land in the Kazuo county increased from 2.1% of the land covered by forest in the 50′s to 31.3% of land covered by forest now.Throughclosing hillsides to facilitate afforestation the area of regenerated forest stands reached up to3.33×10⁴ ha,making up 52.1% of the total forest land.The closing of hillsides to facilitateafforestation includied four major practices,i.e.closing hillsides to livestock grazing and fuelgathering,combination of closing with tending and planting trees,combination of closing andplanting trees,and combination of closing with tending shrubs and planting grasses.Thepractice of closing hillsides to facilitate afforestation is a efficient way to accelerate recoveringforest vegetation.

Key words: Anammox, Nitrogen removal, Autotrophs