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Different fates of deposited NH 4 + and NO 3 − in a temperate forest in northeast China: a 15 N tracer study
Author(s) -
Liu Jun,
Peng Bo,
Xia Zongwei,
Sun Jianfei,
Gao Decai,
Dai Weiwei,
Jiang Ping,
Bai Edith
Publication year - 2017
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.13533
Subject(s) - ecosystem , nitrogen , tracer , environmental chemistry , litter , terrestrial ecosystem , temperate forest , forest ecology , reactive nitrogen , environmental science , nitrogen cycle , sink (geography) , temperate climate , deposition (geology) , biogeochemical cycle , biomass (ecology) , chemistry , ecology , geology , biology , geography , paleontology , physics , cartography , organic chemistry , sediment , nuclear physics
Increasing atmospheric reactive nitrogen (N) deposition due to human activities could change N cycling in terrestrial ecosystems. However, the differences between the fates of deposited NH 4 + and NO 3 − are still not fully understood. Here, we investigated the fates of deposited NH 4 + and NO 3 − , respectively, via the application of 15 NH 4 NO 3 and NH 4 15 NO 3 in a temperate forest ecosystem. Results showed that at 410 days after tracer application, most15 NH 4 +was immobilized in litter layer (50 ± 2%), while a considerable amount of15 NO 3 −penetrated into 0–5 cm mineral soil (42 ± 2%), indicating that litter layer and 0–5 cm mineral soil were the major N sinks of NH 4 + and NO 3 − , respectively. Broad‐leaved trees assimilated more 15 N under NH 4 15 NO 3 treatment compared to under 15 NH 4 NO 3 treatment, indicating their preference for NO 3 − –N. At 410 days after tracer application, 16 ± 4% added 15 N was found in aboveground biomass under15 NO 3 −treatment, which was twice more than that under15 NH 4 +treatment (6 ± 1%). At the same time, approximately 80% added 15 N was recovered in soil and plants under both treatments, which suggested that this forest had high potential for retention of deposited N. These results provided evidence that there were great differences between the fates of deposited NH 4 + and NO 3 − , which could help us better understand the mechanisms and capability of forest ecosystems as a sink of reactive nitrogen.