Effect Of River On Optimum Falling Zone In The Riparian Ecological Indices Of The Soil Nematode

This thesis survey region is based on the river of Anshan-Panjin part whichbelongs to Liao River’s middle and lower reaches as research object. There are5sampling points in this survey region, by field observation and sampling analysis,and also by the contrast of the unaffected of the outside dam to discuss the changesof the soil nematode’s Eco index and the extent of damage about the soil nutrient.The data shows: because of the influence of the river basin, thec-p(colonizer-persister) value、MI index is lower than that in the compare area at theoptimum falling zone in the riparian. The nematode of c-p1to c-p3occupied about90%of the total nematode rates, and the nematode kinds succession at the earlystage, which shows that the soil environment in the optimum falling zone changedvery severe. And the nematode rates of every sampling points’ c-p1, c-p2are allhigher than that in the compare area. All above shows that the soil ecologicalenvironment is not as stable as the compare areas.The proportion index of F/B（Fungivores to baterivores ratio）at the optimumfalling zone in the riparian is total lower than that in the compare area, which showsthe banks that take into the area soil food web feed nematode slightly more likely toeat bacteria channel in the optimum falling zone in the riparian. Nematode channelratio also shows this kind of variation trend.Micro-to plant-feeding nematodes ratiois total lower than that in the compare area. It shows that the banks that take into thearea of food plant which is harmful to the plants have increasing trend.Shannon-Weiner diversity、Evenness and Richness are all lower than that in thecompare area, but the Dominance is higher than that in the compare area. It showsthat the nematode’s variety、the average distribution in the soil and the population’s richdegree are all lower than that in the compare area.The soil exchangeable base of the compare area is1.16times than that in theoptimum falling zone in the riparian, the soil organic matter is1.41times, and thesoil available nitrogen is1.5times, there are a lot of differences. It shows that the soil exchangeable base、 soil organic matter and Soil available nitrogen all have lostin different degrees, especially Ca and Mg, these two parts can occupy91%.Soil exchangeable base、soil organic matter and Soil available nitrogen willreduce with the depth of the soil. This kind of exchange trend especially in thecompare area. Due to the serious natural factors and human factors of interfere,the soil in the optimum falling zone has been destroyed, so contrast with thecompare area, the exchanged trend is not very obvious.