Effect of paddy cultivation on nematode community in Jinchuan Wetland of Changbai Mountain area, China

Soil nematode community composition could change following the conversion of wetlands to agricultural fields. In Jinchuan Wetland of Changbai Mountain area, China, we investigated the soil nematode community in different types of wetland-farmland interaction. Our results suggest that the Shannnon-Weaver diversity index in OW, R30, R1, KN, KP and PF are 2.48, 1.65, 1.70, 1.68, 1.39, 1.98, respectively, which means the native wetland had great biodiversity abundance. The genus of nematodes initially increased upon recovery from farmland, and nematode densities decreased in the tillage and cropping wetlands. Wilsonem and Prismatolaimus were sensitive to tillage. The bacterial-feeder nematodes increased after the first tillage treatment, while the nematode community was in a relatively stable state after a return to wetland following 30 years of agriculture. Plant parasite index (PPI) had about tenfold reduced in paddy farmland in comparison to the original wetland, and the values were positively associated with the change extent of recovery to reclamation of wetland. The study showed that agricultural activities disturbed the diversity of soil nematodes in Jinchuan Wetland. Certain kinds of genus and trophic diversity of the nematode community could indicate the effects of paddy cultivation on the wetland soil ecosystem.