14 巻 (1997) 1 号 p. 37-45
Floristic composition was investigated in the Malus baccata var. mandshurica bush on the sand dunes along the Sea of Okhotsk, in eastern Hokkaido. A phytosociological association, Lonicero - Maletum baccatae, was newly recognized. Its characteristic species are Malus baccata var. mandshurica, Lonicera chrysantha var. crassipes and Sambucus sieboldiana var. miquelii. In the case of the M. baccata var. mandshurica bush, only Roso〜Maletum mandshuricae (Tatewaki 1961) Ohba, Miyawaki et Tx. 1973, has been reported. It belongs to Rosion rugosae Ohba, Miyawaki et Tx. Lonicero-Maletum baccatae lacks Rosa rugosa and Artemisia japonica, but it has many species common to the Angelico anomalae - Quercetum dentatae (Tatewaki 1961) Ohba, Miyawaki et Tx. 1973, the climax forest on coastal sand dunes. It also has many of the character and differential species of its upper unit. Thus Lonicero-Maletum baccatae belongs to Quercion dentatae Miyawaki et Yasushi Sasaki 1980. Fixation of trees in coastal sand dunes is difficult because of the severe environment as a dense sand dune vegetation cover, the strong sea wind and so on. Seeds of M. baccata var. mandshurica are dispersed by birds and can produce root-suckers, allowing it to grow in coastal sand dunes as a pioneer shrub.