Besides the green areas of the world where we expect trees to thrive, you only have to look at several abandoned sites to see how prolific and unstoppable tree growth can be in any circumstance.
Nature always finds a way.
But getting back to basics here, how do trees multiply?
How do trees reproduce? Trees reproduce sexually via the exchange of male pollen to the reproductive systems of a female flower or similar structure, producing seeds that drop and anchor themselves by sending out roots when conditions are ideal. Trees also reproduce asexually through cultivation or natural root regrowth.
Even more so than animals, trees have plenty of evolutionary tricks up their sleeve to ensure life carries on (using some familiar methods and some downright mystifying ones!).
If you ever wanted to know how beautiful new trees come to be in this world, keep reading to understand more about their fascinating process…
Understanding Tree Reproduction
In nature, trees rely on pollen exchange and seed distribution to reproduce. With human intervention, they can also be cloned via propagation.
Deciduous trees produce flowers that need to be pollinated by birds and insects like bees and butterflies in order to reproduce.
The bright colors and pleasing scent of their flowers are relied upon to attract these pollinators (who feed on the flower nectar while unknowingly transferring male pollen stuck to their legs or beaks to the female flower’s stamen).
Fertilization then occurs within the small female flowers, producing seeds.
Evergreen trees, meanwhile, must self-reproduce since they don’t produce fruit or flowers. Evergreens like fir, spruce, and pine trees make pollen in small sacs within their male or staminate cones.
This pollen is then released and carried by the wind with the aim of finding the female cone (or a tree of the same species bearing female cones) to collect and fertilize the pollen via their ovules that each hold an egg cell.
The resulting seeds are then released for when the mature female cone opens up in the dry, warm summer weather.
Depending on the tree and seed type, heavy seeds (like acorns and other nuts) simply drop to the ground and germinate where they land if conditions are favorable (i.e., rich, moist soil, and decent sunlight).
Lighter seeds from maple trees, for example, can be transported by wind, snow, heavy rainfall, or by birds for long distances before sprouting.
Propagation by People
Branch or twig cuttings taken from a healthy tree stem can be planted in new soil.
With the aid of rooting hormone, nutrients, and vigilant care, they will essentially grow into an offspring of the parent tree (find out how you can grow a new tree from twig cuttings here!).
Additional Ways Trees Can Reproduce
Trees can spawn in other unexpected ways. In the right circumstances, new tree growth can emerge from bare roots, broken branches, and even with the help of certain animals!
New Trees Emerging From Exposed Roots
Some trees, such as aspen and poplars, can reproduce asexually by sending new stems out from their exposed roots.
The survival instinct is often so strong in certain species that the exposed stump or root tips of a felled tree will attempt to send out new leafy shoots known as root sprouts or “root suckers” in order to continue nurturing itself.
With time, a whole new grove of trees may be produced, all formed from the cell of the original dying tree!
Natural Tip Layering
In nature, “layering” naturally occurs when a tree falls on another, causing the damaged branches beneath to be pinned to the ground.
In some cases, these trapped pinned-down branches are pressed into the earth for so long that they are tricked into thinking that they must send out their own roots since the fall has disrupted the tree’s hormone distribution and blocked out the sunlight, prompting them to effectively find their own way out of the rubble.
Clever or what?!
This layering process can be encouraged manually in certain trees and shrubs with high success rates in forsythias, dogwoods, and crepe myrtles.
Zoochory (Seed Dispersal via Animals)
Animals such as jay birds and squirrels that love to bury acorns and other heavy tree seeds for the winter inevitably forget about a few, allowing these undisturbed underground tree seeds to germinate and grow anew!
Then there are fruit-hungry birds and other four-legged critters that munch on the berries of certain trees that contain indigestible seeds.
Once these emerge as delightful..erm..fertilizer pellets, the seeds within have a chance to sprout, often miles from the parent tree.
Do Trees Grow Back After Being Cut Down?
Some fast-growing species such as elm, willow, and ficus can regrow from root sprouts due to their aggressive root systems.
This is true of all deciduous trees if enough nutrients remain in the leftover tree stump or roots after being cut down. Slow-growers like oak and pine, however, cannot regrow.
Do Trees Feel Pain?
No, trees do not feel pain. All trees and plants react to physical stimuli and damage (such as in the case of insects eating their leaves or nearby trees being cut down) by emitting electrical signals in order to strengthen their chemical defenses.
However, this is a survival response, not a pain signal since trees lack nerves, pain receptors, and brains.
Tree reproduction is pretty amazing – perfect adaptations in nature such as colorful, fragrant flowers and seeds designed to be carried on the wind make it possible for tree species to produce offspring trees using sexual and asexual methods.
New trees can also be cultivated by us when we propagate them by taking and nurturing the branch/stem cuttings of the original parent tree or by encouraging some of the asexual reproduction techniques we observe in nature, such as layering.