As we've already learned, fires are a huge part of the Pine Barrens ecosystem. They are not only incredibly common, but are actually necessary for the forest to grow!
Serotiny is an adaption in some seed plants in which seeds are released from dropped cones only when the cones are exposed to certain stimuli. Certain trees in the Pine Barrens exhibit this trait, such as the Lodgepole Pine. Serorinous Cones are dropped from trees like the Lodgepole Pine, and contain a wealth of seeds. The cones are coated in a special resin, or thick liquid, that holds the cone shut under normal conditions but melts when exposed to fire. In some plants, exposure to fire simply causes the cone to open up and all of the seeds to fall out in a process called pyriscence, while others, like the Lodgepole Pine, undergo pyrohydriscence, a process in which the cones must first be burned then wetted to open up fully. Serotiny, like all traits, came about through evolution. As we've previously discussed, fire plays an important role in returning nutrients to the soil. As such, the period just after a fire is bound to be the time when the soil is at its most nutrient-rich, making it the best time for seeds to be planted. So, trees that utilize serotinous cones are essentially waiting to plant their seeds until the moment that conditions are perfect for growth. |