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Abstract Warmer winters with less snowfall are increasing the frequency of soil freeze–thaw cycles across temperate regions. Soil microbial responses to freeze–thaw cycles vary and some of this variation may be explained by microbial conditioning to prior winter conditions, yet such linkages remain largely unexplored. We investigated how differences in temperature history influenced microbial community composition and activity in response to freeze–thaw cycles.We collected soil microbial communities that developed under colder (high elevation) and warmer (low elevation) temperature regimes in spruce‐fir forests, then added each of these soil microbial communities to a sterile bulk‐soil in a laboratory microcosm experiment. The inoculated high‐elevation cold and low‐elevation warm microcosms were subjected to diurnal freeze–thaw cycles or constant above‐freezing temperature for 9 days. Then, all microcosms were subjected to a 7‐day above‐freezing recovery period.Overall, we found that the high‐elevation cold community had, relative to the low‐elevation warm community, a smaller reduction in microbial respiration (CO2flux) during freeze–thaw cycles. Further, the high‐elevation cold community, on average, experienced lower freeze–thaw‐induced bacterial mortality than the warm community and may have partly acclimated to freeze–thaw cycles via increased lipid membrane fluidity. Respiration of both microbial communities quickly recovered following the end of the freeze–thaw treatment period and there were no changes in soil extractable carbon or nitrogen.Our results provide evidence that past soil temperature conditions may influence the responses of soil microbial communities to freeze–thaw cycles. The microbial community that developed under a colder temperature regime was more tolerant of freeze–thaw cycles than the community that developed under a warmer temperature regime, although both communities displayed some level of resilience. Taken together, our data suggest that microbial communities conditioned to less extreme winter soil temperatures may be most vulnerable to rapid changes in freeze–thaw regimes as winters warm, but they also may be able to quickly recover if mortality is low. Read the freePlain Language Summaryfor this article on the Journal blog.
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This content will become publicly available on April 1, 2026
Air and soil temperatures in the Appalachian Highlands, Eastern USA: lapse rates, gradients, and applications
Abstract Despite strong terrain influences on the climate of the Appalachian Highlands in the eastern USA, few attempts have been made to systematically collect air and soil temperature data from summits and other high-elevation sites in this region. This paper reports on the Appalachian Highlands Environmental Monitoring (AHEM) mesoscale climate network, a series of 20 high-elevation sites recording temperature at hourly intervals from 1996 to 2008 on Appalachian summits along a 1500 km transect extending from Maine to North Carolina. Observations included air temperature, ground surface temperature, and soil temperature at 25 cm depth. Data were analyzed with respect to four issues: (1) accuracy of air temperature estimates and comparisons with previous studies; (2) relations between the altitude of the 0 °C mean annual air temperature and latitudinal position; (3) variations in frequency distributions of freeze–thaw days with latitude; and (4) the accuracy of an existing soil temperature classification scheme in the Appalachians. Analytic results include: (1) topographically informed interpolation techniques provide more accurate temperature estimates than traditional methods; (2) the elevation of the 0 °C mean annual air temperature decreases systematically with increasing latitude; (3) the frequency distributions of freeze–thaw days are related directly to latitudinal position; (4) classifications of mean annual soil temperature based on data from the 25 cm level are in general agreement with an existing U.S. Department of Agriculture soil-temperature map suggesting permafrost underlying high-elevation locations in the northern Appalachian Highlands..
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- PAR ID:
- 10593317
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- Theoretical and Applied Climatology
- Volume:
- 156
- Issue:
- 4
- ISSN:
- 0177-798X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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