It is said that the largest giant sequoia is not in Yosemite, but in the neighboring Giant Sequoia National Park. The largest is General Sherman Tree, which is over 3500 years old, 83 meters high and 3 1 meter in circumference. It takes about 20 people to hug this tree. The diameter of the first branch 40 meters above the ground is 2 meters. The total weight is about 2000 tons, and it is estimated that 40 medium-sized houses can be built. If you use its wood to make an extra-large wooden box, you can hold the largest ocean-going passenger ship in the world today. The second big tree is General Grant, the third is Poole, the fourth is Hart, and the fifth is Yosemite's giant fir. I used to say it was also 3500 years old. In recent years, with the help of accurate testing methods, its accurate age is 2700 years old. Although this ancient tree is old and its temples are gray, it still bears balls and seeds, and there is no sign of dying.
Giant sequoias are distributed about 400 kilometers west of the Sierra Nevada, with an altitude of 1400-2200 meters. There are 75 communities, ranging from a dozen to thousands. Yosemite has only three huge fir forests. Mixed with the giant fir, there are fir, sugar pine, western yellow pine and cypress. The young tree of giant sequoia is conical, like an inverted ice cream cone. Grow to a few hundred years old, reach the limit height, and begin to develop to be stout. The base branches gradually fall off, the bark thickens, and the trunk is thick and tall, like a giant column. The crown of the tree is getting rounder and rounder, and the branches in the air are getting stronger and stronger, as if there are many big trees across this huge column. But the cone on the tree is only the size of an egg and contains 150-250 seeds. I don't know why, it's hard to see seedlings when you look around the ground. ?
Giant sequoias can live to be over 3,000 years old, which is an unparalleled number for the animal kingdom. The life span of wild animals is not easy to verify.
It is an interesting topic that giant sequoia can live so long and be strong. First of all, it has a wide and smooth nutrition transportation system. Roots are not deep underground, but they extend widely, especially to a depth of about half a meter. The root system is developed, which can absorb water and inorganic salts from the most nutritious stratum. The bark of giant sequoia is thicker than that of any plant on the earth. The average bark of trees over several hundred years old is about 30 cm, and the thickest bark can exceed 60 cm. This is an important reason for the longevity of giant sequoia. This kind of bark has another feature: with the thick trunk, it can be regularly split into deep ditches longitudinally, thus ensuring that the trunk can continue to grow and grow. Secondly, the wet and rainy climate in the western foot of Nevada is suitable for the stratum and soil where big trees stand and grow, which constitutes an ideal environment for giant sequoia. The third important factor is the resilience of giant sequoia. The ability is very outstanding. This kind of tree contains a chemical substance, which has the characteristics of anti-corrosion, insect-proof and mildew-proof. For thousands of years, forest fires have been inevitable. Animals can get away with it, but plants can only be tested by fire. The bark of giant sequoia is 30-60 cm thick near the ground, which contains almost no flammable resin, but is rich in sponges that are not afraid of fire. Therefore, after a wildfire, many plants turned to ashes, but giant sequoia was blessed. The fire not only didn't hurt it, but also helped it clear its competitors, win the growth space, enrich the ground nutrition and enhance its anti-epidemic ability. Therefore, "stand out from the crowd" is more handsome and dignified. Many times, many giant sequoias died not because of aging, but because the trees were too high and heavy, and finally fell down. The causes of dumping are storm, snow pressure on tree crown, ant nesting, soil erosion and the combination of these factors. So some people think that if these objective factors are excluded, the giant sequoia can live to 5000-6000 years old, or even 1 long live. ?
Interestingly, the giant sequoia has two close relatives in the world: one is near and the other is far. Nearby is the coastal redwood not far from the west, which grows in the foggy area near the Pacific coast. The Miaoer Forest National Reserve we are going to is a typical area where this plant grows. In the distance is Metasequoia glyptostroboides, a famous plant in China. 194 1 year was discovered in Lichuan, Hubei, and later in Wanxian, Shizhu, Longshan and Sangzhi, Sichuan. It is considered as an extinct "living fossil" and caused a sensation in botany, so it is one of the eight plants on the first-class protection list in China. The common ancestor of giant sequoia, coastal sequoia and Metasequoia is sequoia in dinosaur era. In Cretaceous and Early Triassic, this kind of plants was the dominant tree species in the northern hemisphere and widely distributed in the middle and high latitudes of Asia and North America. In the process of historical changes, especially after the Quaternary Glacier, these plants have been extinct on a large scale, leaving only these three plants with outstanding characteristics. Distant relatives and unique close relatives like this exist not only in the plant kingdom but also in the animal kingdom. For example, the American alligator in Mississippi and the Chinese alligator in China, the musk ox in North America and the wildebeest in China are far apart but closely related animals. This shows that the earth looks big, but it is not far away. Man and the biosphere are a unity, and naturally there are no national boundaries. ?
Giant sequoia is such a precious historical heritage that it has also experienced a painful history in the United States. In an era known only to Indians, excessively backward electrical appliances are helpless for such a huge tree. It is said that the giant sequoia was cut down in 1852. The first few trees didn't covet its wood, just because it grew too big, too tall and too beautiful. They planned to move it out for exhibition so that everyone could see this treasure of nature. At that time, because the tree was too big to use an axe and a big saw, I took out an iron drill to make a hole, which was a bit like quarrying. The first tree was chosen in the giant sequoia forest in Las Vegas, northern Karaoui. Twenty-five people worked for ten days and punched countless eyes on a spine. Finally, the tree lost its support and balance and fell to the ground with an earth-shattering noise. It is reported that the impact of the trunk on the ground will lift the nearby sand to an altitude of more than 30 meters. This loud noise came from newspapers and public opinion, which also shocked some Americans and issued a call to protect this big tree. But at first, the voice was still weak, which was not enough for those people to "show mercy under the knife." The second doomed giant sequoia is also in the same giant sequoia forest, ready to be transported to the Crystal Palace in Sydenham, England for exhibition. Judging from the name of this tree called "mother of the forest", it also shows another momentum of its male crown. People learned the lesson that the first giant fir was broken. Instead of putting it down, they built a scaffold dozens of meters high, peeled off the bark and shipped it to England. Poor tree "lived" for several years after cutting off the nutrient transportation line until 1908 was destroyed by a wildfire. The third giant sequoia was destroyed at the 1876 Philadelphia Centennial Exhibition. Now look at the bumpy section of the stump, and you will know how difficult it was to put the tree down at that time. In order to prevent the tree from being broken, a thick layer of bedding was laid on the ground before it was put down. The tree fell down and could not be carried away as a whole. Only a part of the skin was peeled off and a specimen was pieced together in Philadelphia. So many viewers still don't believe that there will be such a big tree in the world after reading it, saying it is fake. However, this tree is real, and the trunk that can't be moved is still lying next to General Grant's tree. 189 1 year, another giant fir named Mark Twain was cut down. Judging from the photos left, this is a very beautiful giant fir without fire marks. ?
After all, only a few giant sequoias are cut down for exhibition, and then cut down for economic benefits, and the problem becomes more and more serious. Although the giant sequoia is not as practical as the coastal sequoia, it is not a pillar in architecture because of its low tension and easy to break and dry. However, the output of wood is amazing. The wood of a tree can be used to enclose an 8000-acre pasture and build 70 or 80 wooden roofs. Moreover, in the market at that time, giant sequoias could be mixed with coastal sequoias for sale. Therefore, the destruction and waste caused by cutting down giant sequoias is unimaginable. In order to transport huge timber, the lumberjack also specially opened a 60-kilometer-long channel from the mountain to the canyon. The stumps and ruins left at that time will be an indelible "monument" for human beings to destroy nature. Without centuries, this kind of wound is impossible to heal, or it will never be possible.