Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 319-338 |
| Number of pages | 20 |
| Journal | Biogeochemistry |
| Volume | 142 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Feb 15 2019 |
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All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Water Science and Technology
- Earth-Surface Processes
Cite this
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. / Watanabe, Tsunehiro; Tateno, Ryunosuke; Imada, Shogo; Fukuzawa, Karibu; Isobe, Kazuo; Urakawa, Rieko; Oda, Tomoki; Hosokawa, Nanae; Sasai, Takahiro; Inagaki, Yoshiyuki; Hishi, Takuo; Toda, Hiroto; Shibata, Hideaki.
In: Biogeochemistry, Vol. 142, No. 3, 15.02.2019, p. 319-338.Research output: Contribution to journal › Article
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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
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.
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U2 - 10.1007/s10533-019-00537-w
DO - 10.1007/s10533-019-00537-w
M3 - Article
VL - 142
SP - 319
EP - 338
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 3
ER -