Physical, chemical, and metabolic leaf characteristics within sugar maple in the MELNHE study at Bartlett Experimental Forest, central NH USA, 2017

The MELNHE study looks at patterns of resource limitation through
nutrient manipulations in three study sites in New Hampshire: Bartlett
Experimental Forest, Hubbard Brook Experimental Forest, and Jeffers
Brook, located in the White Mountain National Forest. The
investigation is monitoring stem diameter, leaf area, sap flow, foliar
chemistry, leaf litter production and chemistry, foliar nutrient
resorption, root biomass and production, mycorrhizal associations,
soil respiration, heterotrophic respiration, N and P availability, N
mineralization, soil phosphatase activity, soil carbon and nitrogen,
nutrient uptake capacity of roots, and mineral weathering.
Applications of N and P began in June 2011 and continue at the rate of
30 kg N/ha/yr (as NH4NO3) and 10 kg P/ha/yr (as NaH2PO4). This data set includes physical, chemical, and metabolic leaf
characteristics collected in a vertical transect within individual
tree crowns. Because trees varied in crown depth, not all trees have
the same number of samples collected. Depth from the top of the crown
was measured and climbing ropes and a pole pruner were used to collect
a population of leaves. 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.