Abstract: Vegetation restoration is considered as one of the most effective approaches for enhancing the ecological environment of the Loess Plateau. Investigating the variations in the abundance and structure of soil nematode community within Quercus liaotungensis forest across different restoration durations, along with their underlying driving factors, can offer valuable theoretical support for scientific management of forest ecosystems on the Loess Plateau. With abandoning farmland as the control, changes of soil nematode community of Quercus liaotungensis with the stand age of 30, 60, and 120 years were studied in Ziwu Mountain, Loess Plateau. The results showed that: (1) The dominant genera of soil nematode in Q. liaotungensis forest differed among restoration durations, with Filenchus being the co-dominant genus and Criconemoides becoming a new dominant genus in 60 and 120 years old plantations. (2) There was no significant change in total soil nematode density with increasing durations of restoration. Soil nematode community structure in 30 years old Q. liaotungensis forest was significantly different from abandoned farmland, 60 and 120 years old Q. liaotungensis forest. (3) The proportion of bacterivores showed a trend of first increase and then decrease with increasing restoration years, while that of omnivores-predators showed a fluctuating increasing trend. The proportion of bacterivores significantly and positively correlated with litter biomass and dominant bacterial taxa. The proportion of fungivores was significantly positively correlated with soil ammonium nitrogen and significantly correlated with dominant bacterial and fungal taxa. The proportion of plant-parasitic nematodes was significantly and positively correlated with dominant bacterial and fungal taxa. The proportion of omnivores-predators was significantly and negatively correlated with the dominant fungal taxa. (4) Soil ammonium nitrogen, dissolved organic carbon, and bacterial community structure were the major factors influencing soil nematode community changes in Q. liaotungensis forest with different restoration years. Our results indicated that restoration duration significantly affected the structure of soil nematode communities in Q. liaotungensis forest, and that soil ammonium nitrogen and dominant microbial taxa may be the main factors driving the changes in soil nematode community during vegetation restoration.

Key words: forest restoration duration, Quercus liaotungensis forest, nematode community, trophic group