Forest 15N retention in China;
Fate of fertilizer N in agricultural ecosystem, e.g., retention by crops and soil, losses via N2, N2O, NO and NH3;
15N abundancefor atmospherically deposited N in precipitation, ice core, paleosoils, aerosols, precursors of ammonium and nitrate across different sites;
15N natural abundance of ammonia and NO from different sources, especially from soil;
Isotope fractionationduring denitrification and nitrification;
15N and 13C signatures in tree rings and their implications for characteristics of past N cycling and water use efficiency by trees;
Forest N cycling in response to Warming and N deposition;
Current on-going research projects
1. 2017/01-2019/12, "The contributions of denitrification, anammox, and co-denitrification to soil dinitrogen losses in temperate forests", funded by National Natural Science foundation of China (NSFC).
2. 2016/07-2021/06, "Biological mechanisms underlying the coupled carbon and nitrogen cycling in forests and grasslands from northeastern China", funded by the Ministry of Science and Technology of the People's Republic of China.
2016/01-2020/12, "Impacts of warming and nitrogen deposition on plant nitrogen uptake, soil N cycle and greenhouse gases emission of forests of northeastern China", funded by the Bureau of Frontier sciences and education Chinese Academy of Sciences.
4. 2015/01-2017/12, "Nitrogen cycling in forest ecosystems", funded by the National Science Foundation of China (NSFC).
5. 2015/01-2017/12, "Fate and turnover of atmospherically deposited nitrogen in two typical secondary forest in northeast China: 15N tracer experiment", funded by the National Science Foundation of China (NSFC).
6. 2015/01-2017/12, "Nitrogen uptake preference of typical tree species in northeastern China and its response to nitrogen deposition", funded by the National Science Foundation of China (NSFC).
7. 2014/01-2019/12, "Soil microbes drive nitrogen biogeochemical cycling in cropland soil in Northeast China", funded by Strategic Priority Research Program of Chinese Academy of Sciences.
8. 2014/01-2017/12, "To quantify rates of nitrification and denitrification from forests in southern China using natural abundance of nitrate isotopes", funded by the National Science Foundation of China (NSFC).