Climate Change Across Seasons Experiment (CCASE) Sapling Study at the Hubbard Brook Experimental Forest: Foliar Nitrogen

Foliar nitrogen concentrations of red maple and sugar maple saplings experiencing combinations of soil warming and winter
freeze-thaw cycles were measured during the growing season of 2014 and 2015
as an indicator of plant nitrogen status.

There were seven treatments for each species of maple. For each species, ten saplings experienced ambient
temperatures (reference), ten experienced growing season warming with no induced freeze-thaw cycles in winter
(warmed), ten in each of four groups experienced warming in the growing season coupled with two, four, six, or
eight soil freeze-thaw cycles in winter (warmed + 2 FTC, warmed + 4 FTC, warmed + 6 FTC, warmed + 8 FTC),
and ten experienced snow removal in winter with ambient temperatures in the growing-season (snow removal).