Figure 3. Example shape changes in the normalized band-depth profiles for the 2.30-µm absorption feature in dry leaf data are shown for two samples, white pine (solid line) and red maple (dashed line). The original reflectance spectra have been continuum removed and the band depths normalized to the band center at 2.304 µm. This process clearly shows the different absorption shapes in these two samples. The shape changes are due to varying amounts of absorbers in the dry leaf, including nitrogen contained in proteins, and structural biochemicals such as lignin and cellulose.