Leaf-Litter Production in a Plantation of Alnus Inokumae

(1) Leaf-litter production was investigated from 1973 to 1982 in a plantation of Alnus inokumae. (2) The annual total leaf-fall was relatively constant with a mean of 340 g m-2 year-l except for 2 years when leaf-fall was about 100 g m-2 year-' less due to outbreaks of winter-moth larvae. (3) The seasonal pattern of leaf-fall was bimodal with peaks in summer and autumn in most years. Of the total leaf-fall, 20-35% had occurred by the end of July and 30-60% by the end of August. This summer leaf-fall consisted mainly of the three basal leaves on each shoot. (4) The large summer leaf-fall together with the long period of leaf-emergence are considered to be adaptive to open, mesic sites.