我组成员在 Environmental Science & Technology 上发表文章：Shaonan Huang, Fan Wang, Emily M. Elliott, Feifei Zhu, Weixing Zhu,et al. Multiyear Measurements on Δ¹⁷O of Stream Nitrate Indicate High Nitrate Production in a Temperate Forest [J]. Environmental Science and Technology, 2020. 

　　文章链接：https://pubs.acs.org/doi/10.1021/acs.est.9b07839 

　　Nitrification is a crucial step in ecosystem nitrogen (N) cycling, but scaling up from plot-based measurements of gross nitrification to catchments is difficult. Here, we employed a newly developed method in which the oxygen isotope anomaly (Δ¹⁷O) of nitrate (NO₃^–) is used as a natural tracer to quantify in situ catchment-scale gross nitrification rate (GNR) for a temperate forest from 2014 to 2017 in northeastern China. The annual GNR ranged from 71 to 120 kg N ha^–1 yr^–1 (average 94 ± 10 kg N ha^–1 yr^–1) over the 4 years in this forest. This result and high stream NO₃^– loss (4.2–8.9 kg N ha^–1 yr^–1) suggest that the forested catchment may have been N-saturated. At the catchment scale, the total N output of 10.7 kg N ha^–1 yr^–1, via leaching and gaseous losses, accounts for 56% of the N input from bulk precipitation (19.2 kg N ha^–1 yr^–1). This result indicates that the forested catchment is still retaining a large fraction of N from atmospheric deposition. Our study suggests that estimating in situ catchment-scale GNR over several years when combined with other conventional flux estimates can facilitate the understanding of N biogeochemical cycling and changes in the ecosystem N status.