Vegetation Characteristics And Restoration Effect Of Degraded Swamps In Lesser Khingan Mountains

Wetlands as kidney of the earth, its ecological function and environmental effects are becoming more and more prominent. However, with the continuous increase of human activities it has caused global wetlands’degradation or large areas of atrophy, which has seriously affected and changed the regional ecological balance and global climate environment in recent years. Youhao National Nature Reserve is important wetlands, its typical wetland habitats, special geographical location make it become the survival and breeding habitat for the world’s species of rare waterfowl.In this study we investagated the vegetation structure and plant diversity of three types of degraded swamp:fire disturbed swamp, grazing disturbed swamp and agriculture reclamation disturbed swamp. Using different vegetation construction modes to restore the degraded swamps was systematicly researched. And the adaptation mechanism of wetlands degradation will be revealed by different patterns of vegetation construction. The theoretical basis will be provided for the degraded natural wetlands recovery. The results showed that:1. total23kinds of vascular plants in fire disturbed swamp, belonging to21genera and15families. Include ferns2families2genera and2species, gymnosperms1family2genera and2species, monocots3families5genera7species, dicot9families12genera and12species; total24kinds of vascular plants in grazing disturbed swamp, belonging to22genera and16families. Include ferns2families2genera and2species, gymnosperms1family2genera and2species, monocots3families6genera8species, dicot10families12genera and12species; total17kinds of vascular plants in agriculture reclamation disturbed swamp, belonging to15genera and11families. Include ferns2families2genera and2species, gymnosperms1family2genera and2species, monocots3families4genera6species, dicot5families7genera and7species.2. Before restoration, species richness S index in grazing disturbed swamp was highest, followed by fire disturbance, and agriculture reclamation disturbed swamp was minimal. After recovery, species richness S index of three kinds of disturbed swamps was similar. Plant diversity S index of artificial restoration swamps was higher than natural restoration swamp. Species richness SP index showed:before restoration, species richness SP index of fire disturbed swamp was highest, followed by grazing disturbed swamp, and agriculture reclamation disturbed swamp’s SP index was minimal. Species richness SP index of artificial restoration swamps and three kinds of disturbed swamps after natural recovery was similar. Species richness SP index of artificial restoration swamps was higher than natural restoration swamps. Species richness SW index showed:before restoration, species richness SW index of grazing disturbed swamps was highest, followed by fire disturbance, and agriculture reclamation disturbed swamps’S W index was minimal. Species richness S W index of artificial restoration and three kinds of interference types swamp wetland after natural recovery was sequenced as fire disturbed swamps> grazing disturbed swamps> agriculture reclamation disturbed swamps. Plant diversity SW index of artificial restoration swamp wetland was close to natural restoration swamp wetland. Species evenness Jsw index showed:before restoration, species evenness Jsw index of grazing disturbed swamps was highest, followed by fire disturbed swamps, and agriculture reclamation disturbed swamps’Jsw index was minimal. After recovery, order of Jsw index of three kinds of disturbed swamps did not changed. Plant evenness index of artificial restoration swamps was higher than natural restoration swamps.3. In order to analyze the recovery effect of different plantation modes applied to degraded swamps, plot investigation method and excavation method were used to investigate plant growth index. The results showed:in fire disturbed swamp, pure spruce (Picea aspoerata) plantation was the best one among seven planting systems, trees survival rate was89%after3years of planted. Trees had lower survival rates in other models than the pure spruce planting systems. In grazing disturbed swamp, the recovery effect of the afforestation models of pure spruce forest, pure larch (Larix gmelinii) and mixed larch and spruce forest was better than other models. Trees survival rate were94%,79%and85.5%, respectively. In agricultural reclamation disturbed swamp, the recovery effect of the afforestation models of pure spruce forest, pure larch and mixed larch and spruce forest was better than other models, which was similar with the grazing discurbed swamp. Trees survival rate were92%,85%and83%, respectively. Sea-buckthorn (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 and larch are the recommended species for vegetation recovery in the degraded swamps in Lesser Khingan Mountains.