Inter-annual variations of leaf-fall phenology and leaf-litter nitrogen concentration in a hinoki cypress ( Chamaecyparis obtusa Endlicher) stand.

Inagaki, Yoshiyuki; Sakai, Atsushi; Kuramoto, Shigeo; Kodani, Eiji; Yamada, Tsuyoshi; Kawasaki, Tatsuro

Inter-annual variations in leaf-fall phenology and leaf-litter nitrogen concentration were investigated for 13 years in a coniferous plantation of hinoki cypress trees ( Chamaecyparis obtusa Endlicher) in Kochi, southern Japan. Mean annual nitrogen concentration in the leaf litter ranged from 5.97 to 7.12 g kg−1. The removal of 30 percent of the trees’ basal area in the 3rd year had little effect on leaf-litter nitrogen concentration. The nitrogen concentration in the leaf litter was not correlated with the mean temperature from March to October. The leaf-fall duration, i.e., time between 10 and 90% of the annual leaf fall, was shorter and the leaf-litter nitrogen concentration was lower when the solar radiation from March to October was higher. The results suggest that the hinoki trees shed their leaves abruptly and have lower leaf-litter nitrogen concentration when the solar radiation is higher and that effects of temperature on leaf-fall properties may not be strong in warm climate areas.

JAPAN; NITROGEN; LEAVES; CHAMAECYPARIS obtusa; SOLAR radiation; TREES; MARCH; OCTOBER

Ecological Research, 2008, Vol 23, Issue 6, p965

0912-3814

Academic Journal

10.1007/s11284-008-0461-9