title: Ecological significance of light controlled seed germination in two contrasting tropical habitats.
abstract: The effects of temperature, photoperiod, phytochrome photoreversion and the response to a R/FR ratio gradient were investigated in seeds of four species from two contrasting tropical habitats; two species from a rain forest (Cecropia obtusifolia and Piper umbellatum) and two from a high altitude lava field covered by low vegetation (Buddleja cordata and Chenopodium ambrosioides). In the rain forest seed species the photoblastic response seems to be adapted to light quality changes due to canopy destruction, on the other hand, the lava field seed species seem to be adapted to instantaneous light stimulus such as would be produced by the sudden exposure of a buried seed to the soil surface light environment.
authors.affiliation: Centro de Ecologia, UNAM, Deleg, Coyoacàn, Apartado 70-275, 04510, México, D.F..
authors.forename: C
authors.initials: C
authors.lastname: Vàzquez-Yanes
authors.forename: A
authors.initials: A
authors.lastname: Orozco-Segovia