TY - JOUR
T1 - The effect of a freeze–thaw cycle on dissolved nitrogen dynamics and its relation to dissolved organic matter and soil microbial biomass in the soil of a northern hardwood forest
AU - Watanabe, Tsunehiro
AU - Tateno, Ryunosuke
AU - Imada, Shogo
AU - Fukuzawa, Karibu
AU - Isobe, Kazuo
AU - Urakawa, Rieko
AU - Oda, Tomoki
AU - Hosokawa, Nanae
AU - Sasai, Takahiro
AU - Inagaki, Yoshiyuki
AU - Hishi, Takuo
AU - Toda, Hiroto
AU - Shibata, Hideaki
N1 - Funding Information:
Acknowledgements We would like to thank the collaborators of the ReSIN project (Regional and comparative soil incubation study on nitrogen dynamics in forest ecosystems: PI. Hideaki Shibata), Nobuhito Ohte, Nobuko Saigusa, Keitaro Fukushima, Tsutomu Enoki, Keisuke Koba, Toshizumi Miyamoto, Shin Ugawa and Kobayashi Makoto for their helpful discussions in the development of the manuscript. We would also like to thank Takayuki Yamauchi, Yasuyuki Shibata, Tomoyuki Nakagawa, Ken-ichi Ohta, Yoichiro Kitagawa, Yasunori Kishimoto, and Makoto Furuta, who are technical staff of the Hokkaido forest research station, Field Science Education and Research Center and Kyoto University for their great efforts in the manual snow removal. We would also like to thank Michiko Shimizu and the technical staff of the Northern Forestry and Development Office, Field Research Station, Field Science Center for Northern Biosphere, Hokkaido University, for their support with laboratory analysis. This study was partly supported by research funds (25252026) from the Japan Society for the Promotion of Science; Environment Research and Technology Development Fund (S-15) of the Ministry of the Environment, Japan; Integrated Research Program for Advancing Climate Models (TOUGOU program) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.
Funding Information:
We would like to thank the collaborators of the ReSIN project (Regional and comparative soil incubation study on nitrogen dynamics in forest ecosystems: PI. Hideaki Shibata), Nobuhito Ohte, Nobuko Saigusa, Keitaro Fukushima, Tsutomu Enoki, Keisuke Koba, Toshizumi Miyamoto, Shin Ugawa and Kobayashi Makoto for their helpful discussions in the development of the manuscript. We would also like to thank Takayuki Yamauchi, Yasuyuki Shibata, Tomoyuki Nakagawa, Ken-ichi Ohta, Yoichiro Kitagawa, Yasunori Kishimoto, and Makoto Furuta, who are technical staff of the Hokkaido forest research station, Field Science Education and Research Center and Kyoto University for their great efforts in the manual snow removal. We would also like to thank Michiko Shimizu and the technical staff of the Northern Forestry and Development Office, Field Research Station, Field Science Center for Northern Biosphere, Hokkaido University, for their support with laboratory analysis. This study was partly supported by research funds (25252026) from the Japan Society for the Promotion of Science; Environment Research and Technology Development Fund (S-15) of the Ministry of the Environment, Japan; Integrated Research Program for Advancing Climate Models (TOUGOU program) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.
Publisher Copyright:
© 2019, Springer Nature Switzerland AG.
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Recent global warming models project a significant change in winter climate over the next few decades. The decrease in snowpack in the winter will decrease the heat insulation function of the snowpack, resulting in increased soil freeze–thaw cycles. Here, we examined the impact of winter freeze–thaw cycles on year-round dissolved nitrogen (N) and carbon (C) dynamics and their relationship with dissolved organic matter and microbial biomass in soil by conducting an in situ experimental reduction in snowpack. We investigated dissolved inorganic N (NH 4 + and NO 3 − ), dissolved organic N (DON), dissolved organic carbon (DOC), inorganic N leaching, soil microbial biomass, and microbial activities (mineralization and nitrification) in the surface soil of a northern hardwood forest located in Japan. Experimental snowpack reduction significantly increased the number of soil freeze–thaw cycles and soil frost depth. The NH 4 + content of the surface soil was significantly increased by the amplified soil freeze–thaw cycles due to decreased snowpack, while the soil NO 3 – content was unchanged or decreased slightly. The gravimetric soil moisture, DON and DOC contents in soil and soil microbial biomass significantly increased by the snowpack removal in winter. Our results suggest that the amplified freeze–thaw cycles in soil increase the availability of DON and DOC for soil microbes due to an increase in soil freezing. The increases in both DON and DOC in winter contributed to the enhanced growth of soil microbes, resulting in the increased availability of NH 4 + in winter from net mineralization following an increase in soil freeze–thaw cycles. Our study clearly indicated that snow reduction significantly increased the availability of dissolved nitrogen and carbon during winter, caused by increased soil water content due to freeze–thaw cycles in winter.
AB - Recent global warming models project a significant change in winter climate over the next few decades. The decrease in snowpack in the winter will decrease the heat insulation function of the snowpack, resulting in increased soil freeze–thaw cycles. Here, we examined the impact of winter freeze–thaw cycles on year-round dissolved nitrogen (N) and carbon (C) dynamics and their relationship with dissolved organic matter and microbial biomass in soil by conducting an in situ experimental reduction in snowpack. We investigated dissolved inorganic N (NH 4 + and NO 3 − ), dissolved organic N (DON), dissolved organic carbon (DOC), inorganic N leaching, soil microbial biomass, and microbial activities (mineralization and nitrification) in the surface soil of a northern hardwood forest located in Japan. Experimental snowpack reduction significantly increased the number of soil freeze–thaw cycles and soil frost depth. The NH 4 + content of the surface soil was significantly increased by the amplified soil freeze–thaw cycles due to decreased snowpack, while the soil NO 3 – content was unchanged or decreased slightly. The gravimetric soil moisture, DON and DOC contents in soil and soil microbial biomass significantly increased by the snowpack removal in winter. Our results suggest that the amplified freeze–thaw cycles in soil increase the availability of DON and DOC for soil microbes due to an increase in soil freezing. The increases in both DON and DOC in winter contributed to the enhanced growth of soil microbes, resulting in the increased availability of NH 4 + in winter from net mineralization following an increase in soil freeze–thaw cycles. Our study clearly indicated that snow reduction significantly increased the availability of dissolved nitrogen and carbon during winter, caused by increased soil water content due to freeze–thaw cycles in winter.
UR - http://www.scopus.com/inward/record.url?scp=85060257639&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85060257639&partnerID=8YFLogxK
U2 - 10.1007/s10533-019-00537-w
DO - 10.1007/s10533-019-00537-w
M3 - Article
AN - SCOPUS:85060257639
VL - 142
SP - 319
EP - 338
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 3
ER -
