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Estimating near‐infrared leaf reflectance from leaf structural characteristics
Author(s) -
Slaton Michèle R.,
Raymond Hunt E.,
Smith William K.
Publication year - 2001
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2657019
Subject(s) - trichome , cuticle (hair) , biology , plant cuticle , palisade cell , botany , spongy tissue , photosynthesis , stomatal density , specific leaf area , reflectivity , leaf size , horticulture , anatomy , biochemistry , physics , wax , optics
The relationship between near‐infrared reflectance at 800 nm (NIRR) from leaves and characteristics of leaf structure known to affect photosynthesis was investigated in 48 species of alpine angiosperms. This wavelength was selected to discriminate the effects of leaf structure vs. chemical or water content on leaf reflectance. A quantitative model was first constructed correlating NIRR with leaf structural characteristics for six species, and then validated using all 48 species. Among the structural characteristics tested in the reflectance model were leaf trichome density, the presence or absence of both leaf bicoloration and a thick leaf cuticle (>1 μm), leaf thickness, the ratio of palisade mesophyll to spongy mesophyll thickness (PM/SM), the proportion of the mesophyll occupied by intercellular air spaces (%IAS), and the ratio of mesophyll cell surface area exposed to IAS ( A mes ) per unit leaf surface area ( A ), or A mes / A. Multiple regression analysis showed that measured NIRR was highly correlated with A mes / A , leaf bicoloration, and the presence of a thick leaf cuticle ( r 2 = 0.93). In contrast, correlations between NIRR and leaf trichome density, leaf thickness, the PM/SM ratio, or %IAS were relatively weak ( r 2 < 0.25). A model incorporating A mes / A , leaf bicoloration, and cuticle thickness predicted NIRR accurately for 48 species ( r 2 = 0.43; P < 0.01) and may be useful for linking remotely sensed data to plant structure and function.