TITLE:
Canopy Net Photosynthesis Rate of a Mongolian Oak (Quercus mongolica) Forest Estimated by Field Experimental Data
AUTHORS:
Seung Jin Joo, Soon-Ung Park
KEYWORDS:
Mongolian Oak (Quercus mongolica), Canopy Net Photosynthesis Rate, PPFD, TPAI, Solar Elevation Angle
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.3,
February
6,
2017
ABSTRACT: The canopy net photosynthesis rate of Mongolian oak
(Quercus mongolica) tree species that
are dominant in East Asia and Korea is estimated with empirical models derived
from field experimental data obtained from the Nam-San site in Seoul, Korea for
the growing period from early May to late October in 2010. The empirical models
include the attenuation function of photosynthetic photon flux density (PPFD) (r2 = 0.98-0.99, p r2 = 0.99, p level within canopy significantly varies diurnally
and seasonally due to the seasonal variation of the total plant area
index (TPAI = leaf area index + wood silhouette
area index) and the light shielding effect of light path-length through
the canopy in association with the variation of solar elevation angle.
Consequently, a remarkable seasonal variation of the total canopy net
photosynthesis rate of Q. mongolica forest stand is found for its growing period. The PPFD exceeding 1000 μmol m-2·s-1 is found to cause the decrease of net photosynthesis rate due to the thermal
stress in the early (May) and late (September) growing period. During the whole
growing season, the estimated total canopy net photosynthesis rate is found to
be about 3.3 kg CO2 m-2.