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　　 我组成员在 Ecological Applications 上发表文章：SHANLONG LI, GESHERE ABDISA GURMESA, WEIXING ZHU, et al. Fate of atmospherically deposited NH₄⁺ and NO₃^- in two temperate forests in China: emporal pattern and redistribution. Ecological Applications. 2019, 29(6),1143-1157.

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　　The impacts of anthropogenic nitrogen (N) deposition on forest ecosystems depend in large part on its fate. However, our understanding of the fates of different forms of deposited N as well as the redistribution over time within different ecosystems is limited. In this study, we used the ¹⁵N-tracer method to investigate both the short-term (1 week to 3 months) and long-term (1–3 yr) fates of deposited NH4⁺ or NO₃^- by following the recovery of the ¹⁵N in different ecosystem compartments in a larch plantation forest and a mixed forest located in northeastern China. The results showed similar total ecosystem retention for deposited NH4⁺ and NO₃^-, but their distribution within the ecosystems (plants vs. soil) differed distinctly particularly in the short-term, with higher ¹⁵NO₃^-recoveries in plants (while lower recoveries in organic layer) than found for ¹⁵NH4⁺. The different short-term fate was likely related to the higher mobility of ¹⁵NO₃^-than ¹⁵NH4⁺ in soils instead of plant uptake preferences for NO₃^- over NH4⁺.In the long-term, differences between N forms became less prevalent but higher recoveries in trees (particularly in the larch forest) of ¹⁵NO₃^- than ¹⁵NH4⁺ tracer persisted, suggesting that incoming NO₃^- may contribute more to plant biomass increment and forest carbon sequestration than incoming NH4⁺. Differences between the two forests in recoveries were largely driven by a higher ¹⁵N recovery in the organic layer (both N forms) and in trees (for ¹⁵NO₃^-) in the larch forest compared to the mixed forest. This was due to a more abundant organic layer and possibly higher tree N demand in the larch forest than in the mixed forest. Leachate ¹⁵N loss was minor (<1% of the added ¹⁵ N) for both N forms and in both forests. Total ¹⁵N recovery averaged 78% in the short-term and decreased to 55% in the long-term but with increasing amount of ¹⁵ N label (re)-redistributed into slow turn-over pools (e.g., trees and mineral soil). The different retention dynamics of deposited NH₄ ⁺ and NO₃ ^- may have implications in environmental policy related to the anthropogenic emissions of the two N forms.