<div>Fig 1. Map showing the study location; a and b represent Zhangbei County
and <i>P. simonii</i> Carr shelterbelts, respectively.</div><div>Fig 2. Climate diagram for Zhangbei County covering the period from
1980-2018.</div><div>Fig 3. Initial soil temperature and soil water content levels for the
study site in Zhangbei County.</div><div>Fig 4. The traces of the soil temperature in Zhangbei Country (10, 30,
50, 70, 90, 110, 130, 150, 170 and 190 cm depth; freezing-thawing
progress from 1<sup>st</sup> Dec. 2018 to 26<sup>th</sup>May 2019).</div><div>Fig 5. Dynamic variations in air temperature (a) and soil temperature
(b) at depths of 10, 30, 50, 70, 90, 110, 130, 150, 170, and 190 cm
throughout the experimental period in Zhangbei County.</div><div>Fig 6. Correlation between air temperature and upper soil temperature
(0-20, 20-40, and 40-60 cm) in Zhangbei County.</div><div>Fig 7. Dynamic variations in air temperature (a) and soil water content
(b) at depths of 10, 30, 50, 70, 90, 110, 130, 150, 170, and 190 cm
throughout the experimental period in Zhangbei County.</div><div>Fig 8. Changes in the freezing front (a) and the thawing front (b) at
each soil layer in Zhangbei County.</div><div>Fig 9. Soil water content throughout the freeze–thawing period (a) and
increase in the soil water content at different soil depths (b)
(freeze–thawing period from December 1, 2019, to May 26, 2019).</div>