Inter‐annual variations of leaf‐fall phenology and leaf‐litter nitrogen concentration in a hinoki cypress ( <i>Chamaecyparis obtusa</i> Endlicher) stand

Abstract

Abstract 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.