Serotiny

For example, Pinus halepensis exhibits primarily fire-mediated serotiny,[3] but responds weakly to drying atmospheric conditions.

[4] Similarly, Sierras sequoias and some Banksia species are strongly serotinous with respect to fire, but also release some seed in response to plant or branch death.

In the southern hemisphere, fire-mediated serotiny is found in angiosperms in fire-prone parts of Australia and South Africa.

It is extremely common in the Proteaceae of these areas, and also occurs in other taxa, such as Eucalyptus (Myrtaceae) and even exceptionally in Erica sessiliflora (Ericaceae).

In the northern hemisphere, it is found in a range of conifer taxa, including species of Pinus,[5] Cupressus, Sequoiadendron, and more rarely Picea.

[8] The fire-release mechanism is commonly a resin that seals the fruit or cone scales shut, but which melts when heated.

For example, North American populations of lodgepole pine (Pinus contorta) can vary from being highly serotinous to having no serotiny at all, opening annually to release seed.

In Australia, for example, fire-mediated serotiny occurs in areas that not only are prone to regular fires but also possess oligotrophic soils and a seasonally dry climate.

[16] Similar pressures apply in Northern Hemisphere conifer forests, but in this case there is the further issue of allelopathic leaf litter, which suppresses seed germination.