Seed germination of burned site pioneer plants affected by heat treatment after incubation for several months.

Abstract

We examined the seed germination response of representative pioneer plants following a forest fire to short-time heat treatment after incubation for several months. Heat treatment was conducted for the seeds which could not germinate during the initial incubation. Among the twelve species examined, Solanum lyratum Thunb., Broussonetia kazinoki Sieb., Phytolacca americana L., Ampelopsis brevipedunculata Trautv., Vitis coignetiae Pulliat., and Smilax china L. were accelerated in germination by treatment conducted four months and six months after sowing, i.e., 50℃ in the day and 25℃ at night for two days. These results indicate that 1) seeds of these species are at least partly not germinative under conditions of ordinal incubation but that 2) germination of such seeds can be accelerated by heat when they are left under moist, incubation conditions. Such germination behavior is likely to be a characteristic of moist seeds and to occur in pioneer plants at burned sites in Japan, which has a wet, temperate climate.