Oak can be seen everywhere in our life, from oak barrels and elegant pianos that give wine a unique flavor to cradles and wooden horses for children and floors at home. But do you know what kind of world oak stands silently in the vast wilderness?
In fact, every elegant oak tree is a wonderful little kingdom, where thousands of creatures live, get old, get sick and die. As long as you are calm and patient enough, you will find these secrets.
Vibrant "air city"
There are two cities in the oak kingdom: the city on the ground and the city in the air. Every city has its own unique environment, and residents with different responsibilities live here.
The roots of oak trees are often covered with all kinds of moss, so the city on the ground is also called the moss layer. The residents here are mainly decomposers, such as mites, centipedes and earthworms. An oak tree has more than 300,000 leaves every year, weighing about 100 kg. If we don't get rid of them, the forest will be flooded by a steady stream of fallen leaves sooner or later. The decomposer's duty is to consume these fallen leaves. They feed on litter and finally convert it into substances that can be reused by oak trees.
Moss layer is an ideal hunting ground for small carnivores such as toads-lush moss provides them with a safe hiding place, where they can safely wait for their prey (mainly insects and decomposers).
The "city in the air" above the ground is more lively. Owls live here. They like to nest in branches or tree holes. Once they settle down, they will not leave until the end of their lives.
Living next to the owl is a woodpecker. They are doctors in the oak tree. The woodpecker can peck at the trunk continuously at the speed of 20 times per second to catch moths inside. They have shock absorbers in their heads, so they won't get dizzy.
Also living in the treetops are oak moths with soft spots. Its larvae feed on oak leaves. Every April, thousands of caterpillars gather together to form a long chain of more than ten meters, like a huge predatory fleet. These caterpillars have more than 600,000 poisonous stinging hairs. If people touch them carelessly, they will be painful, itchy and even life-threatening.
Of course, if you are interested, you can also come to live in the Oak Kingdom. Oak trunk is thick and leafy, which is very suitable for building tree houses. Horace Burgess, an American architect, built the world's largest tree house on six adjacent oak trees-about 30 meters high, with five floors and 80 rooms. In addition to housing, this tree house also has a small basketball court, a church, a choir attic and so on, and its functions are quite complete.
Shudong Inn, with constant passenger flow.
In addition to these permanent residents, of course, many tourists will come to the bustling oak kingdom. There is a tree hole inn in the Oak Kingdom to provide accommodation for these animals.
For example, raccoons like to live in Oak Inn because it provides accommodation and food delivery services: they sleep in tree holes and eat acorns when they wake up, trying to accumulate thick fat for winter.
Bumblebee also likes to seek refuge here: it has high military value, but it makes too many enemies, so it often looks for a safe hiding place, and Shudong Inn meets this requirement. Bumblebees are very picky and will build nests in tree holes-they use the pulp produced by chewing bark to build nests.
Petite and beautiful blue tits sometimes come here to nest and lay eggs. They are also very picky and like comfortable environment, so they will spread soft, comfortable and beautiful moss, grass or feathers in the oak hole.
Snakes, ladybugs, bats and other animals also love to come to Shudong Inn for the winter, because the stable and safe environment here is very suitable for them to hibernate.
Do your best to die.
In addition to shelters, the Oak Kingdom provides residents with leaves and acorns as food, and they are also oxygen factories or nursery rooms.
Oak grows very slowly, and it takes half a century to accumulate energy from germination to first flowering. When the temperature rises and the cold weather is driven away by spring, the oak tree wakes up from hibernation. The buds on the branches can't wait to "bloom", sticking out curly leaves and showing their existence to spring. Soon, the iconic leaves of oak trees with shallow cracks will cover the treetops, providing fresh and delicious food for all kinds of herbivorous residents who eat dry food in winter.
There are also some animals that use oak leaves as nursery rooms, such as the leaf weevil. Before laying eggs, the female leaf weevil will cut off the leaves of the oak tree, roll up both sides of the leaves with her long kiss and legs, fold them into a delicate nest, and then lay eggs in it.
In addition, the leaves of oak trees are oxygen factories and air filters. An oak tree with 100 years has about150,000 leaves, which can convert 6 tons of carbon dioxide into 4.5 tons of oxygen every year. As an air filter, oak leaves have a total surface area of 1600 square meters and can filter out 1 ton of dust every year.
Flowers and leaves bloom at the same time Oaks are monoecious, but pistils and stamens grow on different flowers. The pollen of the male flower is carried to the female flower by the wind, and finally bears an acorn with fluffy end and bare end.
Acorn is rich in sugar, fat and protein, and its yield is extremely high. It is an important food source for many animals in autumn and winter. The output of acorns directly affects whether these animals can survive the cold winter safely. But interestingly, although people always associate squirrels with acorns, for example, squirrels in the movie Ice Age always hold an acorn, but squirrels actually don't like acorns. Because squirrels can't digest acorns effectively, they often have stomachaches after eating them.
Many animals eat and drink for free, but some inadvertently help oak trees to sow, such as Jay. In autumn, Jay likes to hide acorns in the soil as winter food. But confused, they usually can't find these acorns anymore, so young oak seedlings will grow in these places next year.
But some insects (such as leaf miner, oak beetle larvae) eat more fiercely, which will cause harm to oak trees. They can dive directly into leaves and tender bark tissues and feed on fresh and juicy cells. Like hungry ghosts, almost all mesophyll tissues have been hollowed out. In severe cases, leaves will wither, and photosynthesis can no longer be carried out, resulting in slow growth and even death of oak trees.
After death, oak is still an important food source, breeding ground and hiding place for countless animals. It can be said that "I will die wholeheartedly"! For example, shovel beetles like to lay their eggs on rotten oak trees, so that when babies hatch, they will find many delicious foods around them to enjoy. Woodpeckers also like to use dead wood to build houses for their offspring. When woodpeckers leave their nests with wings, these rooms are often taken over by owls, hazel Dormice or squirrels and become hiding places.
Does the oak tree have a resurrection switch?
But oak trees don't die so easily. Many times, even if it has been eaten bare by pests, the majestic oak tree can still exude vitality. So what exactly is oak's trick to deal with pests eating?
Oaks have a large number of dormant buds. Normally, these dormant buds will not germinate, but if the oak tree is seriously damaged, these dormant buds will wake up and grow new branches in the next spring. In this way, even if the leaves are eaten up by animals, the oak tree can be revived in the shortest time.
Dormant buds are not the only means for oak trees to cope with various threats. In cold regions such as Europe, oak trees need to prepare for the cold winter. In late autumn, before the leaves leave the branches, oak trees will absorb important nutrients in the leaves, such as chlorophyll, and then store them in the trunk and roots to spend the cold winter. And the thick bark can keep warm and moisturize. Oak trees can also produce antifreeze to prevent cells from cracking due to internal water freezing.
These conservation strategies ensure that the oak tree can store enough energy to survive the cold winter, sprout and grow new branches and leaves in the next spring, and start a miraculous life journey again. Therefore, the life of oak trees is very long, and it is not a problem to live for hundreds or thousands of years. For example, Bosop oak in Lincolnshire, England is over 65,438+0,000 years old, and Pechanga oak in California, USA is even over 2,000 years old.
The oldest creature in the world.
However, the oldest oak tree in the world is an unremarkable shrub on Jurupa Mountain in the southern suburbs of California. It has stood on Mount Pa in Ru Ru for 13000 years. People named it Jurupa Oak after this mountain.
More than ten years ago, this strange Palmer oak attracted the attention of scientists in a plant diversity survey in Mount Jurupa. Palmer Oak is a small tree-like oak, which should grow in a colder and wetter place at higher altitude, instead of being squeezed between two dry granite boulders and being blown by the hunting wind on the mountain.
At first, people thought it was a bush composed of 70 oak trees, but after years of observation, only four acorns were found, and none sprouted, so everyone speculated that it should be a tree and reproduce asexually. Later DNA analysis also confirmed this point: all branches really originated from the same plant.
There are burning marks around Jurupa oak tree, so scientists speculate that the trunk of this oak tree may be burned by wildfire, and new branches have been sprouting from the living roots, helping the oak tree survive again and again. Subsequently, the remains of the trunk were decomposed, leaving only the newly sprouted branches to spread around, forming a bush that is now 25 meters long and about 1 meter high.
In other words, Jurupa oak is at least 12.5 meters long in one direction. The growth rate of Jurupa oak is about 0.8 mm per year. If estimated at this rate, it will take 15600 years to develop to the present scale. Even if the past environment is more suitable for its growth, its growth rate is similar to that of ordinary Palmer oak (0.96 mm/year), and it takes at least 13000 years.
When the Jurupa oak began to sprout, the earth was in the ice age. At that time, Ru Ru Pashan was colder and wetter than it is now, so it could germinate and grow smoothly.
If the researchers' speculation is correct, then Jurupa Oak is the oldest creature in the world!
This article comes from the article 12, 20 16 of The Mystery of Science.