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Are wildfires an adapted ecological cue breaking physical dormancy in the Mediterranean basin?

Published online by Cambridge University Press:  09 January 2015

Ganesh K. Jaganathan
Ganesh K. Jaganathan*
Affiliation:
Institute of Biothermal Technology, University of Shanghai for Science and Technology, Shanghai 200093, China
*
*Correspondence E-mail: [email protected]
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Abstract

Many studies have claimed that fire acts as the chief ecological factor cueing dormancy break in seeds with a water-impermeable seed coat, i.e. physical dormancy (PY), in Mediterranean ecosystems. However, a proposal is made that seasonal temperature changes must be viewed as more meaningful dormancy-breaking cues because: (1) fire is erratic and may break PY in seasons during which seedlings cannot complete their life cycle; (2) fire may not occur for long periods, thereby only providing an opportunity for dormancy break and germination once in every several years; and (3) if fire opens the specialized anatomical structures called ‘water gaps’, in seconds, their evolutionary role of detecting environmental conditions becomes irrational. Although fire breaks dormancy in a proportion of seeds, given the risk of seed mortality and the post-fire environment providing cues for dormancy break, it is suggested that fire might possibly be an exaptation.

Keywords

adaptationdry heatexaptationgermination timinghigh temperaturepost-fire environmentseasonal temperaturewater-impermeable seed coatwater gap
Type
Research Opinion
Information
Seed Science Research , Volume 25 , Special Issue 2: Seed Dormancy , June 2015 , pp. 120 - 126
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Copyright
Copyright © Cambridge University Press 2015 

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