title: Accurate measurement of optical properties of narrow leaves and conifer needles with a typical integrating sphere and spectroradiometer.
abstract: Accurate information on the optical properties (reflectance and transmittance spectra) of single leaves is important for an ecophysiological understanding of light use by leaves, radiative transfer models and remote sensing of terrestrial ecosystems. In general, leaf optical properties are measured with an integrating sphere and a spectroradiometer. However, this method is usually difficult to use with grass leaves and conifer needles because they are too narrow to cover the sample port of a typical integrating sphere. Although ways to measure the optical properties of narrow leaves have been suggested, they have problems. We propose a new measurement protocol and calculation algorithms. The protocol does not damage sample leaves and is valid for various types of leaves, including green and senescent. We tested our technique with leaves of Aucuba japonica, an evergreen broadleaved shrub, and compared the spectral data of whole leaves and narrow strips of the leaves. The reflectance and transmittance of the strips matched those of the whole leaves, indicating that our technique can accurately estimate the optical properties of narrow leaves. Tests of conifer needles confirmed the applicability.
authors.affiliation: Faculty of Life and Environment Sciences, University of Tsukuba, Tsukuba, 305-8572, Japan. hibiki.noda@gmail.com
authors.forename: Hibiki M
authors.initials: HM
authors.lastname: Noda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Motohka
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Murakami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Muraoka
authors.forename: Kenlo Nishida
authors.initials: KN
authors.lastname: Nasahara
mesh_terms: D055620:Optical Phenomena; D028223:Pinus / Q000033:anatomy & histology / Q000502:physiology; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000502:physiology*; D029963:Quercus / Q000033:anatomy & histology / Q000502:physiology; D012621:Seasons; D013057:Spectrum Analysis / Q000295:instrumentation*; D064028:Tracheophyta / Q000033:anatomy & histology* / Q000502:physiology*
keywords: Aucuba japonica; Pinus densiflora; conifer needle; grass leaf; reflectance; transmittance