Revista Chilena de Historia Natural 77 (1): 201-215, 2004
REVIEW ARTICLE
Seed bank and dormancy in plants of the Mediterranean region of central
Chile
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.
Key words:
seeds in soil,
germination strategies, germination requirements, germination delay, germination period
