James E. Bedison and Brenden E. McNeil. 2009. Is the growth of temperate forest trees enhanced along an ambient nitrogen deposition gradient? Ecology 90:1736–1742.

Appendix C. Figures showing basal area increment response of tree species between 1984 and 2004 along the nitrogen deposition gradient.

FIG. C1. Relationship of the log10 basal area increment (BAI) between 1984 and 2004 and nitrogen deposition in all (A) size class 1 species and (B) all size class 2 species in spruce–fir plots.

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FIG. C2. Relationship of the log10 basal area increment (BAI) between 1984 and 2004 and nitrogen deposition in (A) size class 1 and (B) all size classes of Acer rubrum stems. Open symbols represent stems from a plot where field notes indicated an open canopy and thus growth may have also been elevated due to increased light availability. Omitting stems from that site in the regression analysis, we find (A) R2 = 0.11, P = 0.04, m = 0.29, mean response = 4.6 × 10-5 and (B) R2 = 0.04, P = 0.16, m = 0.22, mean response = 6.9 × 10-5.

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FIG. C3. Relationship of the log10 basal area increment (BAI) between 1984 and 2004 and nitrogen deposition in (A) size class 1 and (B) all size classes of Abies balsamea stems in spruce–fir and northern hardwood plots.

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FIG. C4. Relationship of the log10 basal area increment (BAI) between 1984 and 2004 and nitrogen deposition in size class 1 Picea rubens stems in northern hardwood plots.