Ecosystem Processes Show Uniform Sensitivity to Winter Soil Temperature Change Across a Gradient from Central to Cold Marginal Stands of a Major Temperate Forest Tree
Weigel, R., H. A. Henry, I. Beil, G. Gebauer, G. Jurasinski, M. Klisz, E. van der Maaten, L. Muffler and J. Kreyling. 2021.
Abstract
The magnitude and frequency of soil frost events
might increase in northern temperate regions in
response to climate warming due to reduced insulation caused by declining snow cover. In temperate deciduous forests, increased soil frost severity
can hamper tree growth and increase the mortality
of fine roots, soil fauna and microorganisms, thus
altering carbon and nutrient cycling. From single-site studies, however, it is unclear how the sensitivities of these responses change along continental
gradients from regions with low to high snowfall.
We conducted a gradient design snow cover and
soil temperature manipulation experiment across a
range of lowland beech forest sites to assess the
site-specific sensitivity of tree growth and biogeochemical cycling to soil cooling. Even mild and
inconsistent soil frost affected tree increment, germination, litter decomposition and the retention of
added 15N. However, the sensitivity of response
(treatment effect size per degree of warming or
cooling) was not related to prevailing winter cli-
mate and snow cover conditions. Our results support that it may be valid to scale these responses to
simulated winter climate change up from local
studies to regional scales. This upscaling, however,
needs to account for the fact that cold regions with
historically high snowfall may experience increasingly harsh soil frost conditions, whereas in warmer regions with historically low snowfall, soil frost
may diminish. Thus, despite the uniform biotic
sensitivity of response, there may be opposing
directions of winter climate change effects on
temperate forests along continental temperature
gradients due to different trends of winter soil
temperature.
Key Words
European beech; forest ecology; frost sensitivity; global change ecology; gradient experi- ment; snow manipulation experiment; winter ecology.
