Tsukuba`s LIVING FOSSILS- it`s Dawn Redwoods (metasequoia, メタセコイア)- Turn Brick-Red Before They Lose Their Leaves
By Avi Landau It being one of my favorite places in Tsukuba, I try to get to the botanical garden AT LEAST twice a month- though when I can, I go EVERY WEEK! In this way I try to follow the seasonal, monthly, and weekly changes which take place within its conveniently located (near the university) confines, the never-ending series of blossomings and witherings- as well as the comings and goings of various insects and birds which are attracted to its fantastic diversity. Since I often visit on weekdays ( when I am most likely the only visitor there) and have little time to spare, I find it very helpful to pick up one of the printouts available near the entrance (updated weekly) which give information about what is going on (botanically) in the garden. They always give a convenient (though highly subjective) ranking of what is best to see in a particular week and there is a map showing you how to get to each one.
Interestingly, this week`s number one ranked attraction at the Tsukuba Botanical Garden can been noticed quite clearly from the parking lot ( or from the road,even). Towering above the orientation building ( the building through which everyone enters) are rows of tall trees which look almost the same- except for the fact that they are alternately brick-colored and deep green- creating a curious color contrast. But though the trees look quite similar, they are not the same. The deep green ones are the evergreen Sequoia sempervirens, natives of North America and those which have turned color and are losing their leaves are the deciduous Metasequoia glyptostroboides (also known as dawn redwoods), natives of China, which have been planted along what is called the garden`s Promenade.
Even though they have turned this strange, dull, rusty brick-color, you could hardly say that these metasequoias are especially interesting to look at. But the fact is that their STORY is amazing- it might even make them the most interesting trees that you can find in Tsukuba (and there are quite a few of them around this city)- they are veritable LIVING FOSSILS! In the year 1939 the Japanese botanist Shigeru Miki (三木茂) discovered some tree fossils in Wakayama and Gifu Prefectures. What he found appeared to be similar to a North American sequoia (an evergreen), but were apparently deciduous ( a tree that loses its leaves in a specific season). These fossils were of tree which was at that time not yet known to science. Miki named the tree METASEQUOIA to mean that it was like a sequoia- but had changed (into a deciduous tree). He reported this to the scientific world in 1941. This tree was from then known exclusively as a fossil, and with the most recent one being 1.5 million years old, it was deemed that this tree had been LONG extinct.
And then amazingly at almost the same time- during the Second World War, an unfamiliar tree was found and noted by a forester in what is now Lichuan County, Hubei Province, China. He was apparently carrying out a survey of China`s remoter areas on behalf of wealthy aristocrats who were seeking a peaceful refuge from the war which was intensifying after Japan`s invasion. The forester spoke to local villagers who told them that they called this huge tree, which was on the grounds of a local shrine, the water-fir (SHUI SA). As the war continued to rage on, no further investigations of this were carried out until 1944 when a researcher from China`s Central Office for Forestry Research located this tree and brought samples back to Nanjing. Specialists in the capital were at a loss as to the identity of this tree and eventually came to realize that they had come across a previously unrecorded species. In 1946, Dr. Hu Hsen Su of the Beijing Botanical Institute, who was familar with the Japanese botanist Shigeru Miki`s paper, was examining the specimens of the Hubei Province mystery tree when he realized that what he had were specimens of METASEQUOIA! In 1948 Hu, along with his esteemed colleague Wan Chun Cheng of the National Central University of Nanjing published a paper reporting their exciting discovery- that the tree Miki had identified was not extinct at all, but had somehow survived in a remote part of China. In the same year, after hearing of the discovery Harvard University`s Arnold Arbortum sent a group of researchers to gather seeds. Seedling were raised and the LIVING FOSSIL has since then been cultivated extensively both in China and abroad. More than 5,ooo of these trees were eventually identified in Lichuan County where they had been growing naturally. But these original trees are apparently in danger of dying out despite being strictly protected in China. This is because while damaging the actual tree is prohibited, so many seed cones are taken for cultivating elsewhere in China that the tree are not reproducing in there natural habitat! They will of course continue to live as roadside and park trees in China and throughout the world (in appropriate climatic zones)- though there has even been a problem with these cultivated trees which consist of a very narrow range of gentic stock: since the Harvard Arbortum did not collect seeds from more than a handful of trees from which all the first saplings were created!
In 1995 a special preserve dedicating to the dawn redwood (as the metasequoia is also called) was created in North Carolina. For much more information on this tree see: http://www.dawnredwood.org/ But you don`t have to go to China or North Carolina to look at , touch (or hug) these LIVING FOSSILS. There are plenty right here in Tsukuba. Learn how to identify them at the botanical garden- and then you can go hunting for them in parks, on the roadside, and on the grounds of various national institutes.
The English language homepage for the Tsukuba Botanical Garden can be found here: http://www.tbg.kahaku.go.jp/english/