@article{oai:tsukuba.repo.nii.ac.jp:00016609,
 author = {奈佐原（西田）, 顕郎 and Nakaji, Tatsuro and Ide, Reiko and Takagi, Kentaro and Kosugi, Yoshiko and Ohkubo, Shinjiro and Nishida, Nasahara Kenlo and Saigusa, Nobuko and Oguma, Hiroyuki},
 issue = {5},
 journal = {Agricultural and forest meteorology},
 month = {May},
 note = {application/pdf, To clarify the utility of spectral vegetation indices (VIs) for estimating light conversion
efficiency (e) in Japanese coniferous forests, we investigated the relationships between six
VIs (NDVI, EVI, SAVI, PRI, CI, and CCI) and e in two mature monospecific forests of deciduous
conifer (Japanese larch) and evergreen conifer (Japanese cypress) and one young mixed
stand of deciduous conifer with evergreen undergrowth (hybrid larch and dwarf bamboo). In
each forest canopy, we measured seasonal variations in CO2 flux, radiation environment,
and visible–near-infrared spectral reflectance during 1 or 2 growing seasons.Wecalculated e
as gross primary production (GPP) divided by the difference between incoming and reflected
photosynthetically active radiation (PAR). VIs and e under clear skies were averaged between
11:00 and 13:00 JST and their relationships were analyzed.
In the larch forest, all calculated VIs were positively correlated with e, and the highest
correlation was that with CCI. Because of effects of extreme reduction in PRI in autumn
with needle yellowing, the correlation of e and PRI was relatively small in this forest. In the
cypress forest, on the other hand, no significant correlation was found except with PRI and
CCI. The highest correlation in this forest was that with PRI, suggesting that the leaf
biomass-related VIs based on near-infrared reflectance are not sufficient for estimating e of
evergreen forest. In the mixed forest, with relatively sparse vegetation cover, all VIs were
significantly correlated with e, but the best correlation was that with SAVI, possibly owing
to the reduction in the effect of the reflectance from background soil. Correlation analysis
of the pooled data from all forests showed the highest correlation between e and PRI.
These results indicate that PRI is an effective VI in the remote estimation of e in both
deciduous and evergreen forests, although there are some sensitivity differences between
vegetation types.},
 pages = {776--787},
 title = {Utility of spectral vegetation indices for estimation of light conversion efficiency in coniferous forests in Japan},
 volume = {148},
 year = {2008}
}