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). 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.