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WonderFire ecology fact

Some lodgepole pines keep their seeds inside cones sealed shut with resin. The heat of a forest fire melts the seal and releases the seeds onto freshly cleared, ash-rich ground.

Serotiny

NatureClimateEvolutionScience

The story behind the card

Botanists call this trait serotiny, from a Latin word meaning 'late': the cones open late, once heat has melted their resin, typically at around 45 to 60 degrees Celsius. Sealed cones can keep seeds alive on the branches for many years, so a stand carries its own seed bank long before any fire arrives. The strategy became famous after the Yellowstone fires of 1988, when many burnt slopes filled with young lodgepole pines within a few years. Not every tree does it. In some populations most cones stay sealed, while in others most open each year like ordinary cones, a mix that tends to follow how often fire has struck the area.

Türkçe oku
Bazı kıvrık çamlar tohumlarını reçineyle sımsıkı kapanmış kozalaklarda saklar. Orman yangınının sıcağı reçineyi eritince tohumlar serbest kalır ve yangının açtığı, külle beslenmiş toprağa düşer.

Botanikçiler bu özelliğe serotini der; kelime Latincede “geç” anlamına gelen bir sözcükten gelir. Bu kozalaklar gerçekten de geç açılır: sıcaklık genellikle 45-60 °C'yi bulup reçineyi eritince. Kapalı kozalaklar tohumları dalda yıllarca canlı tutabilir; böylece ağaçlar, daha yangın çıkmadan kendi tohum ambarını taşır. Bu strateji 1988'deki büyük Yellowstone yangınlarından sonra ün kazandı: birkaç yıl içinde yanmış yamaçların çoğu genç kıvrık çamlarla doldu. Her ağaç böyle değildir. Kimi toplulukta kozalakların çoğu kapalı kalır, kimisinde her yıl kendiliğinden açılan sıradan kozalaklar ağır basar; bu dağılım genellikle bölgede ne sıklıkla yangın çıktığına bağlıdır.

Sources and further reading

Background reading: Serotiny
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