Influences of forest cover on soil freeze-thaw dynamics and greenhouse gas emissions through the regulation of snow regimes: A comparison study of the farmland and forest plantation

Lixin Chen; Zuosinan Chen; Guodong Jia; Jie Zhou; Jiachen Zhao; Zhiqiang Zhang

doi:10.1016/j.scitotenv.2020.138403

Influences of forest cover on soil freeze-thaw dynamics and greenhouse gas emissions through the regulation of snow regimes: A comparison study of the farmland and forest plantation

Sci Total Environ. 2020 Jul 15:726:138403. doi: 10.1016/j.scitotenv.2020.138403. Epub 2020 Apr 8.

Authors

Lixin Chen¹, Zuosinan Chen², Guodong Jia², Jie Zhou³, Jiachen Zhao², Zhiqiang Zhang⁴

Affiliations

¹ Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China; Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China; School of Soil and Water Conservation, Beijing Forestry University, Beijing, China. Electronic address: myclover17@bjfu.edu.cn.
² Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China; Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China; School of Soil and Water Conservation, Beijing Forestry University, Beijing, China.
³ Beijing General Station of Agro-environment Monitoring, Beijing, China.
⁴ Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China; Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China; School of Soil and Water Conservation, Beijing Forestry University, Beijing, China. Electronic address: Zhqzhang@bjfu.edu.cn.

PMID: 32320872
DOI: 10.1016/j.scitotenv.2020.138403

Abstract

Vegetation cover has implications for seasonally frozen soil dynamics and greenhouse gas emissions. We examined the frozen soil dynamics and N₂O and CO₂ efflux in a forest plantation (Populus ssp.) and farmland. The experiments were carried out at a forest reclamation site in Zhangbei county, Hebei province, China, from November 2017 to May 2018. Compared to the farmland, the forest plantation prolonged the retention of frozen soil because the shallower snow and the longer duration of snow cover in the forest contributed to a deeper frost depth and delayed soil thawing. The canopy also sheltered the frozen soil from the extreme fluctuations in freeze-thaw cycles (FTCs) during the snow-free period. Contrasting snow regimes and FTC dynamics contributed to variations in CO₂ and N₂O between the forest plantation and the farmland. Path analysis showed that the soil water content and soil temperature were the main regulators of N₂O and CO₂ emissions, respectively, in both land-use types. By contrast, soil substrate and microorganism biomass minimally influenced N₂O and CO₂ efflux. In conclusion, forest cover influences frozen soil dynamics and greenhouse gas emissions by buffering temperature fluctuations in both snow-covered and snow-free periods. This study further highlights the potential importance of anthropogenic land-use changes in influencing the cold season energy balance and gas efflux in future milder winter climates.

Keywords: Farmland; Forest plantation; Frozen soil; Greenhouse gas emission; Snow cover.

MeSH terms

Carbon Dioxide / analysis
China
Farms
Forests
Greenhouse Gases*
Seasons
Snow
Soil

Substances

Greenhouse Gases
Soil
Carbon Dioxide