Leaf absorptances of Mohave and Sonoran desert plants.

Leaf absorptances to solar radiation in the 400-700 nm (photosynthetically useful wavelengths) are presented for a diversity of species in the Mohave and Sonoran Deserts of North America. As a life form shrubs are shown to have the widest range of absorptance, with perennial herbs and cacti exhibiting a smaller range, and very little variation in leaf absorptances among trees and annuals. The measurement of leaf absorptance at 625 nm is shown to be the same as the leaf absorptance to solar radiation over the 400-700 nm. Over a wide range of species and absorptances, the total solar leaf absorptance (400-3,000 nm) is shown to be closely related to the 400-700 nm leaf absorptance.