Shallow soil temperatures influence ecosystem carbon cycling and the
temperature of deeper soil layers where permafrost thaw occurs.
Vegetation affects shallow soil temperatures via impacts on the surface
energy balance, hydrology, and soil characteristics. Vegetation may
influence the degree to which soil temperatures rise with increases in
air temperature under global climate change. However, variability in
vegetative influences on soil temperature are not well quantified at a
pan-Arctic scale. We compiled data from 235 sites across high latitude
permafrost regions to examine the influence of air temperatures and
vegetation on shallow soil temperatures. Annual thermal regimes varied
across vegetation types characterized by dominant plant functional
cover. The overall magnitude of soil temperature maxima and minima
varied across plant functional types. Ecosystems dominated by vegetation
with tall statured canopies such as evergreen needleleaf boreal forests
and tall shrub tundra tended to have warmer soil warmer temperatures
than tundra sites dominated short statured vegetation such as graminoid
or short shrub species. Soil temperatures increased with air temperature
similarly within tundra vegetation types, and rising air temperatures
from global climate change may result in similar increases in soil
temperatures regardless of vegetation type in the tundra. Soil
temperatures were highly variable and decoupled from air temperature in
boreal forest sites.