  The investigation of leaf-level traits in response to varying environmental
conditions has immense importance for understanding plant ecology. Remote
sensing technology enables measurement of the reflectance of plants to make
inferences about underlying traits along environmental gradients. While much
focus has been placed on understanding how reflectance and traits are related
at the leaf-level, the challenge of modelling the dependence of this
relationship along environmental gradients has limited this line of inquiry.
Here, we take up the problem of jointly modeling traits and reflectance given
environment. Our objective is to assess not only response to environmental
regressors but also dependence between trait levels and the reflectance
spectrum in the context of this regression. This leads to joint modeling of a
response vector of traits with reflectance arising as a functional response
over the wavelength spectrum. To conduct this investigation, we employ a
dataset from a global biodiversity hotspot, the Greater Cape Floristic Region
in South Africa.
