Restoration techniques of degraded swamp in Xiaoxing'an Mountains, northeastern China

In this study, three types of disturbed (fire, grazing and reclamation) degraded swamps were investigated in Youhao National Nature Reserve. To analyze the recovery effect of different planting systems applied to degraded swamps, plot investigation method and excavation method were used to investigate plant growth index. The results showed that: in fire disturbed swamp, pure spruce (Picea koraiensis) plantation was the best one among seven planting systems, the survival rate of tree was 89% 3 years after planting, and quite low in other planting systems. In grazing disturbed swamp, the recovery effect of the afforestation with either pure spruce or pure larch (Larix gmelinii) or mixed larch and spruce forest was satisfactory, and the survival rates of tree were 94%, 79% and 85.5% respectively. In agricultural reclamation disturbed swamp, the recovery effect of the afforestation with either pure spruce or pure larch or mixed larch and spruce forest was similar to the grazing discurbed swamps with survival rates 92%, 85% and 83% respectively. Seabuckthorn (Hippophae rhamnoides) had lowest survival rates ( 36%) in all these disturbed swamps, it is not a suitable species for vegetation recovery in the degraded swamps in this area. Spruce (P. koraiensis) and larch (L. gmelinii) are the recommended species for vegetation recovery in the degraded swamps in Xiaoxing'an Mountains of northeastern China.