Revista chilena de historia natural
versión impresa ISSN 0716-078X
FIGUEROA, JAVIER A. y JAKSIC, FABIAN M.. Seed bank and dormancy in plants of the Mediterranean region of central Chile. Rev. chil. hist. nat. [online]. 2004, vol.77, n.1, pp. 201-215. ISSN 0716-078X. doi: 10.4067/S0716-078X2004000100016.
Seed banks on Mediterranean regions display characteristics that distinguish them from the seed banks of other regions. A seed bank is the concentration of viable propagules buried in the soil for variable periods of time. Seed banks in the Chilean matorral are chiefly transient and functionally similar to seed banks in other Mediterranean ecosystems not disturbed by fire, except for those of Australia. A transient seed bank is that composed of seeds that cannot survive in the upper levels of the soil for more than 1 year. The density of herb seeds in the Chilean matorral soil is one of the highest among Mediterranean ecosystems anywhere in the world, and a large proportion of these seeds is made up of seeds without dormancy that germinate easily, particularly annual grasses. With respect to the dormancy mechanisms that may be responsible for the behavior of these seeds stored in the transient bank, our analysis revealed the following germination syndromes: (1) species whose seeds must be stratified in cold due to the presence of physiological dormancy (particularly introduced herbs), (2) species whose seeds must be scarified with acids or mechanical means due to the presence of physical dormancy (mainly native woody species) and, (3) species that present physiological dormancy and need heat stratification to activate germination (both native and introduced species). These syndromes determine that the timing of germination in central Chile has an autumn and an early spring phase. Besides, there is absence of sporadic germination syndromes for the components of a persistent seed bank. We propose a structural and functional model of the seed bank for the matorral of central Chile that should be enriched with future research
Palabras clave : seeds in soil; germination requirements; germination delay; germination period.