The Nitrogen Deposition Backdrop Soil Nematode Diversity Dynamic Research

The biodiversity dynamics of soil nematodes were studied by stimulating nitrogendeposition in Feng Ling National Natural Reserves, Wu Ying District, Yi Chun City.The soil nematodes were extracted by using sucrose density centrifugation method. Thecharacters of soil nematodes were researched by genera numbers, relative abundance,ecological index, etc. under the background of nitrogen deposition.(1) Each ecological index of soil nematode community was changed in differentnitrogen concentration corresponding to control sample plot. This phenomenon showedthat nitrogen deposition influenced the distribution of soil nematode community to someextent.(2) The total number of soil nematode,Bacterivores(BF),Fungivores(FF), Plantparasites(PP) and Predators-Omnivores(OP) were positive correlation with the totalcarbon and nitrogen of soil, but not related to the C/N ratio.(3) The fourteen families and24genera of nematodes were identified in this study.Bacterivores(BF) was most abundant including10genera, the second one was Plantparasites(PP) and Predators-Omnivores (OP) each including6genera. TheFungivores(FF) was fewest including2genera. The Bacterivores was the dominantgroup of nematode. It was shown that bacteria were rich in soil ecological system.(4) The nematodes were used to gather in the surface layer of soil. They mainlydistributed in0~20cm layer. The nematode quantity was decreased along with the depthof soil. The distribution of nematode quantity looked like "U" shape from May toSeptember. The nematode quantity was most abundant in May and September, and waslowest in July. It was possibly related to temperature and amount of precipitation. TheAcrobeloides genus was dominant in each sample plot.(5) The total number of Acrobeloides genus was increased when nitrogen deposition was increase, but Aphelenchus genus was decreased which was commongenera. The Eudorylaimus genus was disappeared when nitrogen deposition wasincrease. The response of different nematode genera to nitrogen addition level wasdifferent, especially the uncommon genera which was sensitive to nitrogen additionlevel. When nitrogen addition level rose, the common genera were possibly disappearedwhich determine the stability of the biodiversity of nematode community.