Title: Partitioning plant spectral diversity into alpha and beta components

Plant spectral diversity — how plants differentially
interact with solar radiation — is
an integrator of plant chemical, structural, and
taxonomic diversity that can be remotely sensed. We propose to
measure spectral diversity as spectral variance, which allows the
partitioning of the spectral diversity of a region, called
spectral gamma (γ) diversity, into additive alpha (α;
within communities) and beta (β; among communities) components. Our method
calculates the contributions of individual bands or spectral features to
spectral γ-, β-, and α-diversity, as well as
the contributions of individual plant communities to spectral diversity.
We present two case studies illustrating how our approach can identify
“hotspots” of spectral α-diversity within a region, and discover
spectrally unique areas that contribute strongly to β-diversity.
Partitioning spectral diversity and mapping its spatial components has
many applications for conservation since high local diversity and
distinctiveness in composition are two key criteria used to determine the
ecological value of ecosystems.