Climate Change Across Seasons Experiment (CCASE) at the Hubbard Brook Experimental Forest: growth and enzyme activity traits of soil fungi isolated from CCASE in July 2017, grown under a common garden experiment in the laboratory that mimicked CCASE soil temperature treatments

Projections for the northeastern U.S. indicate that mean air
temperatures will rise and snowfall will become less frequent, causing
more frequent soil freezing. To test fungal responses to these
combined chronic and extreme soil temperature changes, we conducted a
laboratory-based common garden experiment with soil fungi that had
been subjected to different combinations of growing season soil
warming, winter soil freeze/thaw cycles, and ambient conditions for
four years in the field. We found that fungi originating from field
plots experiencing a combination of growing season warming and winter
freeze/thaw cycles had inherently lower activity of acid phosphatase,
but higher cellulase activity, that could not be reversed in the lab.
In addition, fungi quickly adjusted their physiology to freeze/thaw
cycles in the laboratory, reducing growth rate and potentially
reducing their carbon use efficiency. Our findings suggest that less
than four years of new soil temperature conditions in the field can
lead to physiological shifts by some soil fungi, as well as
irreversible loss or acquisition of extracellular enzyme activity
traits by other fungi. These findings could explain field observations
of shifting soil carbon and nutrient cycling under simulated climate
change. These data were gathered as part of the Hubbard Brook Ecosystem Study
(HBES). The HBES is a collaborative effort at the Hubbard Brook
Experimental Forest, which is operated and maintained by the USDA
Forest Service, Northern Research Station.