Effects Of Different Vegetation Restoration Methods On Soil Nematode Community Structure And Flora In Mining Dump

The mining of open-pit coal mines produces a vast majority of dumps,which are detrimental to grasslands.Therefore,ecological restoration of the dumps in the mining area is particularly important.Plant communities,soil physical and chemical properties and heavy metals were mainly used as the indicators of the revegetation in the mine dumps in a host of previous studies,however,the weight and attention of soil animals were lacking.Herein,the soil nematodes were taken as indicator organisms to assess artificially restored mine dumps for 9 years,artificial restoration for 5 years,and natural restoration.Results showed that:(1)The quantity of soil nematodes was higher in artificial vegetation restoration treatments than that in natural restoration in the dumps(P?0.05).The mean density of soil nematodes was 215/100 g dry soil regardless of treatments,these nematodes belonged to 5 orders,25 families,48 genera.The vegetation restoration method affected the soil nematode nutritional groups and c-p groups.The artificial revegetation increaseed the number of plant parasitic nematodes,bacterial-eating nematodes and omnivorous predatory nematodes.The number of plant-parasitic nematodes were the least in natural restoration treatment.(2)The Shannon-Weiner index of 5-year artificial restoration on the eastern slope was ignificantly lower than other treatments(P?0.05).The analysis for the weight of soil nematode showed that at the 0-10cm soil layer,the 5-year artificial restoration on the eastern slope was in the B-quadrant,indicating that it is with low or moderate interference,and the food web is stable;the 5-year and 9-year artificial restoration on the southern slope were in the C-quadrant,indicating that these treatments are with little perturbation,and the food web is relatively stable;the 9-year artificial restoration on the eastern slope,natural grasslands and natural restoration treatment were al in the D-quadrant,indicating that the soil nutrients in these treatment are poor,the environment is stressed and the food web is degraded.At the10-20 cm layer,the revegetation treatments were all in the C-quadrant that means the food web is stable,while the natural restoration treatment was in the D-quadrant indicatig the food web is degraded.(3)Revegetation treatments all decreased the soil pH value of the 0-10cm soil layer in the dumping areas.The order of soil moisture content was natural grasslands>revegetation treatments? natural restoration treatment.There were differences in the types and numbers of plants under different vegetation restoration treatments,the species and number of plants in natural grasslands were the largest;The vegetation restoration also increased plant species over time,and the plant species and quantity was the highest in the eastern slope of the 9-year artificial restoration and the lowest in the natural restoration treatment.(4)Redundancy analysis between soil nematode community index,soil physical and chemical properties,and plant diversity was manipulated,and we found soil pH,soil organic carbon content,soil available phosphorus content,alkaline nitrogen content,plant number and species had a greater impact on soil nematode community index;and the number of soil nematodes was positively correlated with soil organic carbon content,plant species and quantity,while negatively correlated with soil pH,available potassium content,and alkaline nitrogen content.The indicators that can indicate the vegetation restoration effect of the mine dump are:the number of soil nematodes,types of soil nematodes,the number and proportion of bacteria-eating nematodes,the number and proportion of omnivorous predators,and the Shannon-Weiner index of soil nematode communities(H'),Marglef richness index(SR),enrichment index(EI)and structural index(SI).