The seeds remain inside of the cone and the cone will grow and harden around them. Pinecones often begin green and soft, and later harden and turn brown as they mature. Many of the cones remain closed around the seeds to protect them, then open up when conditions are optimal for the seeds to leave the tree and become planted.
Pine trees may actually vary their pine cone production year to year as a way of throwing off predators and to increase the rate of successful reproduction. Different environmental conditions can also influence when cones are produced. These factors include water levels, nutrient availability, temperature, and sunlight conditions. The pine cone itself is only a structure meant to protect the seeds inside. On each scale of a single female pine cone, there are two seeds held inside.
The seeds are carried away by the wind, or eaten and then redistributed by animals. Pine cones increase the survival rate of the next generation of pine trees by covering and protecting the vulnerable seeds inside. The closed cone offers a barrier from natural elements such as weather as well as animals trying to eat the seeds. Though the hard bark of the pine cone is edible for many different animals — the seeds, or pine nuts, inside are considered a treat for humans.
Pine cones grow on pine trees. They are how pine trees reproduce , or, in other words, make more trees. Usually, male and female pine cones are born on the same tree. Typically, the male cones, which produce pollen , are located on the lower branches of the tree. This is to prevent the pollen from falling on the female cones of the same tree. When you imagine a pine cone, you are probably imagining a female pine cone with woody, spirally scales.
This is because male pine cones are much smaller and live only for a short length of time, usually in the spring. Male pine cones do not make the hard-shelled woody case like the female pine cones do. They are soft and spongy. Female pine cones use their woody structure to keep their seeds safe. They keep their seeds safe so the seeds can hopefully be pollinated and grow. Each female pine cone has numerous spirally arranged scales, with two seeds on each fertile scale. Male pine cones produce pollen, which is like a powder.
The male cones release their pollen, which is carried around the air by blowing wind, and hopefully to another female pine cone on a different pine tree. If the pollen reaches a female pine cone, this process is called pollination. After pollination, and as time passes usually about two to three years , the pollinated pine seeds grow and eventually peel loose and off of the cone and fall to the ground.
If a good spot for the seed is available, a new pine tree will grow! However, there are many ways fertilized pine seeds can move from place to place. The male pine cones are at the bottom of the photo. Animals eat pine seeds, move to another area, and spread them around by defecation, or in other words, pooping them out.
If the pine seeds are in a windy environment, they can be blown around and spread. On some pine cones, the scale with the nutlike seed, can expand to form a wing for airborne dispersal. Pine cones can move around by falling into water. Pine cones float. Currents can carry seeds across oceans, lakes and rivers, and they end up on shores where they can grow. Humans plant pine seeds to create tree farms. They also find pine cones and move them.
Have you ever picked up a pine cone and carried it away? Plants cannot run away from a fire, so some some species of pine trees developed a way to help their seeds survive. Some species of pine tree need the heat from a fire for their cones to open and release seeds. Did you know that female pine cones open and close depending on the weather? When it is in a damp or cold place, the scales close up tightly. This is how a female pine cone protects its seeds.
Depending on the tree species, these can take anywhere from one year to several years to ripen into the brown, dry cones that are more readily apparent on the tree or on the ground around the tree. At the point where the cones become fully brown, they are fully ripened and the seeds have likely already been dispersed or are in the process of dispersing.
The cone itself is only the protective covering for the seeds inside, and on most trees, there will be several seasons worth of cones developing on the tree, each at different stages of ripening. It is usually in the fall of the year when pine cones drop to the ground. The typically dry condition of late summer and fall is the trigger that causes most cones to ripen, open and distribute their seeds to the wind. Most new pine trees begin when the tiny seeds are blown about by the wind once released from the cone, although some are begun when birds and squirrels feed on the seeds and distribute them.
You can identify animal feeding by looking for the remnants of pine cones on the ground around the tree.
The term serotiny refers to a plant in which the maturation and release of seeds are dependent on certain environmental conditions. A prime example is found in several species of pines that are serotinous, using fire as the trigger to release seeds.
The jack pine Pinus banksiana , for example, will hold its pine cone seeds until the heat of forest fire causes the cones to release their seeds.
This is an interesting form of evolutionary protection, as it ensures the tree will reproduce itself after a disaster. A huge number of new trees sprang up in Yellowstone National Park after terrible forest fires in , thanks to pine trees that were serotinous to fire. So if you can't simply plant a pine cone to grow a new tree , how do you do it? Even if you plant a cone with mature seeds just about to drop, you will have planted the seeds too deep.
The moisture of the ground and the woody cone material trapping the seeds will prevent them from germinating. A pine seed actually needs only light contact with the soil to germinate. If you're intent on germinating your own pine tree seeds, you will need to collect the very small seeds from the cone and prepare them for planting. These seeds have little "seed wings" that help scatter them to the ground surrounding the parent tree.
Nurseries collect the maturing green cones, dry these cones to open the scales and manually extract the seeds for growing seedlings.
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