Wikipedia
Serotiny is an ecological adaptation exhibited by some seed plants, in which seed release occurs in response to an environmental trigger, rather than spontaneously at seed maturation. The most common and best studied trigger is fire. However, the term serotiny refers more broadly to plants that release their seeds over a long period of time, irrespective of the trigger or whether release is spontaneous. In this sense, the term is synonymous with bradyspory.
Possible triggers include
- Death of the parent plant or branch (this death can be caused by fire). This form of serotiny has been termed necriscence.
- Wetting (hygriscence)
- Warming by the sun (soliscence)
- Drying atmospheric conditions (xeriscence)
- Fire (heat, essentially: pyriscence)
- Fire followed by wetting (pyrohydriscence)
Fire is the most common and best studied case.. Some plants may respond to more than one of these triggers. For example Pinus halepensis exhibits primarily fire-mediated serotiny, but responds weakly to drying atmospheric conditions. Similarly, some Banksia species are strongly serotinous with respect to fire, but also release some seed in response to plant or branch death.
Serotiny can occur in various degrees. Plants that retain all of their seed indefinitely in the absence of a trigger event are strongly serotinous. Plants that eventually release some of their seed spontaneously in the absence of a trigger are weakly serotinous. Finally, some plants release all of their seed spontaneously after a period of seed storage, but the occurrence of a trigger event curtails the seed storage period, causing all seed to be released immediately; such plants are essentially non-serotinous, or facultatively serotinous.