TY - JOUR
T1 - Global soil nitrogen cycle pattern and nitrogen enrichment effects
T2 - Tropical versus subtropical forests
AU - Elrys, Ahmed S.
AU - Zhu, Qi Lin
AU - Jiang, Chunlan
AU - Liu, Juan
AU - Sobhy, Hamida H.H.
AU - Shen, Qunli
AU - Uwiragiye, Yves
AU - Wu, Yanzheng
AU - El-Tarabily, Khaled A.
AU - Meng, Lei
AU - Müller, Christoph
AU - Zhang, Jinbo
N1 - Publisher Copyright:
© 2023 John Wiley & Sons Ltd.
PY - 2023/4
Y1 - 2023/4
N2 - Tropical and subtropical forest biomes are a main hotspot for the global nitrogen (N) cycle. Yet, our understanding of global soil N cycle patterns and drivers and their response to N deposition in these biomes remains elusive. By a meta-analysis of 2426-single and 161-paired observations from 89 published 15 N pool dilution and tracing studies, we found that gross N mineralization (GNM), immobilization of ammonium ((Formula presented.)) and nitrate ((Formula presented.)), and dissimilatory nitrate reduction to ammonium (DNRA) were significantly higher in tropical forests than in subtropical forests. Soil N cycle was conservative in tropical forests with ratios of gross nitrification (GN) to (Formula presented.) (GN/ (Formula presented.)) and of soil nitrate to ammonium (NO3−/NH4+) less than one, but was leaky in subtropical forests with GN/ (Formula presented.) and NO3−/NH4+ higher than one. Soil NH4+ dynamics were mainly controlled by soil substrate (e.g., total N), but climatic factors (e.g., precipitation and/or temperature) were more important in controlling soil NO3− dynamics. Soil texture played a role, as GNM and (Formula presented.) were positively correlated with silt and clay contents, while (Formula presented.) and DNRA were positively correlated with sand and clay contents, respectively. The soil N cycle was more sensitive to N deposition in tropical forests than in subtropical forests. Nitrogen deposition leads to a leaky N cycle in tropical forests, as evidenced by the increase in GN/ (Formula presented.), NO3−/NH4+, and nitrous oxide emissions and the decrease in (Formula presented.) and DNRA, mainly due to the decrease in soil microbial biomass and pH. Dominant tree species can also influence soil N cycle pattern, which has changed from conservative in deciduous forests to leaky in coniferous forests. We provide global evidence that tropical, but not subtropical, forests are characterized by soil N dynamics sustaining N availability and that N deposition inhibits soil N retention and stimulates N losses in these biomes.
AB - Tropical and subtropical forest biomes are a main hotspot for the global nitrogen (N) cycle. Yet, our understanding of global soil N cycle patterns and drivers and their response to N deposition in these biomes remains elusive. By a meta-analysis of 2426-single and 161-paired observations from 89 published 15 N pool dilution and tracing studies, we found that gross N mineralization (GNM), immobilization of ammonium ((Formula presented.)) and nitrate ((Formula presented.)), and dissimilatory nitrate reduction to ammonium (DNRA) were significantly higher in tropical forests than in subtropical forests. Soil N cycle was conservative in tropical forests with ratios of gross nitrification (GN) to (Formula presented.) (GN/ (Formula presented.)) and of soil nitrate to ammonium (NO3−/NH4+) less than one, but was leaky in subtropical forests with GN/ (Formula presented.) and NO3−/NH4+ higher than one. Soil NH4+ dynamics were mainly controlled by soil substrate (e.g., total N), but climatic factors (e.g., precipitation and/or temperature) were more important in controlling soil NO3− dynamics. Soil texture played a role, as GNM and (Formula presented.) were positively correlated with silt and clay contents, while (Formula presented.) and DNRA were positively correlated with sand and clay contents, respectively. The soil N cycle was more sensitive to N deposition in tropical forests than in subtropical forests. Nitrogen deposition leads to a leaky N cycle in tropical forests, as evidenced by the increase in GN/ (Formula presented.), NO3−/NH4+, and nitrous oxide emissions and the decrease in (Formula presented.) and DNRA, mainly due to the decrease in soil microbial biomass and pH. Dominant tree species can also influence soil N cycle pattern, which has changed from conservative in deciduous forests to leaky in coniferous forests. We provide global evidence that tropical, but not subtropical, forests are characterized by soil N dynamics sustaining N availability and that N deposition inhibits soil N retention and stimulates N losses in these biomes.
KW - global change
KW - leaky or conservative nitrogen cycle
KW - nitrogen cycle
KW - nitrogen deposition scenarios
KW - nitrogen loss
KW - tropical and subtropical forests
UR - https://www.scopus.com/pages/publications/85147300540
UR - https://www.scopus.com/pages/publications/85147300540#tab=citedBy
U2 - 10.1111/gcb.16603
DO - 10.1111/gcb.16603
M3 - Article
C2 - 36660889
AN - SCOPUS:85147300540
SN - 1354-1013
VL - 29
SP - 1905
EP - 1921
JO - Global Change Biology
JF - Global Change Biology
IS - 7
ER -