イチイガシの発芽および当年生実生の初期生長について : アラカシ, シラカシと比較して

抄録

Acorns of three species of Quersus distributed in the Nara Basin, Cyclobalanopsis-Quercus glauca, Q. myrsinaefolia and Q. gilva were sown in the laboratory in the springs of 1985,1986 and 1987. Following the sowing, seed germination, and the height and growth of seedings were monitored for a year. Although the three species are closely related, the condition of germination and the growth character of Q. gilva seed and seedling stages differed from those of Q. glauca and Q.myrsinaefolia. Q. gilva seeds required higher temperatures and moisture levels than the other species to germinate ; a feature which correlates with the distribution of Q. gilva forests in Japan. The shoot growth of Q. gilva was slow and its rate of leaf emergence was lower than that of the other species, suggesting the seeding of Q. gilva to be shade tolerant. These results also suggest that Q. gilva is better able to occupy stable habitats than Q. glauca and Q. myrsinaefolia. During the course of the experiment a high percentage of Q. gilva individuals failed to achieve leaf emergence, and most of these individuals perished prematurely.