Study On Soil Seed Bank Characteristics And Vegetation Restoration Potential In The Lower Reaches Of Tumen River Wetland

Wetland soil seed bank is the material basis for natural regeneration and succession of the wetland vegetations.The size of the soil seed bank and its species composition,diversity and richness are available to assess the recovery potential of wetland vegetation.Its reserves are in direct proportion to the rate of recovery of the corresponding ecosystem after the damage.In this paper,different types of wetland soil seed bank in the lower reaches of the Tumen River is selected as the research object and seven standard samples of four types of wetlands in the lower reaches of the Tumen River are selected.This paper explores the characteristics of different types of wetland soil seed banks in the lower reaches of the Tumen River and its application potential in the ecological restoration of wetland vegetation by three methods,soil sampling,surveying the wild vegetation and different water condition germination control test of indoor seed bank.The main findings:(1)Dominant species in wetland soil seed bank of the Tumen River are rich,with the potential of germplasm resources for wetland vegetation restoration.The reserves of the soil seed vault are generally declining in the vertical direction as the depth increases.Sixty species were present in this experiment,and the seedlings were 14723.Under the conditions of wet treatment,there were 46 species that were significantly higher than the submerged/submerged water.However,in the number of seedlings of germinated plants,the seed bank germination was 60%of the total soil seed vault.It shows that the hydrological res toration is of great significance in the restoration of wetland vegetation downstr eam of the Tumen River.(2)The species composition of the above-ground vegetation community in the wetland of the Tumen River is rich.There are 79 species of plants of the above-ground vegetation community by investigation,which belong to 28 families and 58 genera.Among them,dominant species are Gramineae,Cyperaceae,Compositae,Polygonaceae.The amount of vegetation within the vegetation community in various wetland areas is obviously different.Lake type wetland has the highest density of vegetation(1144-1458 plants/m2).From the important value of the species of vegetation,Scripus Triqueter,Nutgrass Flatsedge and so on is dominant species in bog wetland and natural lake type wetland.The other wetland sites have tended to be drought-resistant.And the weeds such as Jing,barnyardgrass and so on have the advantages of prominent grasses.(3)The plant species appeared in the process of germination of soil seed bank in the lower reaches of Tumen River,and the similarity coefficient of plant species reached 80.77%.But the similarity coefficients of the germplasm species and aboveground vegetation communities varied greatly,and the similarity coefficients were between 7.14%and 42.86%,which indicated that the vegetati on and seed migration process were affected by the external habitat.The results showed that the restoration potential of damaged wetland(similarity coefficient:42.86%)in lake wetland was larger than that in other plots.(4)There were some differences in soil seed bank characteristics and above ground vegetation community characteristics in the lower reaches of the Tumen River,which were mainly due to the increase of the number of species in the whole vegetation.But the ratio of perennial species and wet vegetative species declined.From the species biodiversity index,the soil seed vault of wetland ecological system,which is disturbed by human disturbance,and earthly vegetation are more stable.(5)For the characteristics of vegetation community structure of different we tland types,appropriate repair techniques should be selected during the restoration of wetland vegetation.For example,natural restoration method is more suitable for areas with disturbance degree within a certain threshold;surface sediment removal method which is applicable to areas that are strongly disturbed.Although they may need to be replanted;the seed bank transplant method has a good effect on the restoration of species that rely mainly on asexual reproduction,but there are difficulties in large area application.