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Canopy photosynthetic production in a Japanese larch stand. I. Seasonal and vertical changes of leaf characteristics along the light gradient in a canopy
Author(s) -
Kurachi Nahoko,
Hagihara Akio,
Hozumi Kazuo
Publication year - 1992
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/bf02347094
Subject(s) - canopy , photosynthesis , larch , growth rate , respiration , respiration rate , leaf area index , dry weight , atmospheric sciences , botany , zoology , biology , horticulture , mathematics , geometry , physics
In an 18 year old Japanese larch stand, leaf characteristics such as area, weight, gross photosynthetic rate and respiration rate were studied in order to obtain basic information on estimating canopy photosynthesis and respiration. The leaf growth courses in area and weight from bud opening were approximated by simple logistic curves. The growth coefficient for the area growth curve was 0.155–0.175 day −1 , while that for the weight growth was 0.112–0.117 day −1 . The larger growth coefficient in area growth caused the seasonal change in specific leaf area ( SLA ) that increased after bud opening to its peak early in May at almost 300 cm 2 g −1 and then decreased until it leveled off at about 140 cm 2 g −1 . The change in SLA indicates the possibility that leaf area growth precedes leaf thickness growth. The relationship between the coefficients a and b of the gross photosynthetic rate ( p )‐light flux density (1) curve ( p=bI/(1+aI) ) and the mean relative light flux density ( I′/I 0 ) at each canopy height were approximated by hyperbolic formulae: a=A /( I′/I 0 )+ B and b=C /( I′ / I 0 )+ D . Leaf respiration rate was also increased with increasing I′/I 0 . Seasonal change of gross photosynthetic rate and leaf respiration rate were related to mean air temperature through linear regression on semilogarithmic co‐ordinates.