Tokyo’s wilderness within

by Eli Kirzner

Special To The Japan Times

What did our cities’ natural landscapes originally look like? In a sprawling metropolis such as Tokyo, with concrete encrusting almost every inch of earth, walling every riverbank and towering up to the skies, it is almost impossible to imagine.

Thankfully, the Institute for Nature Study in the heart of the capital maintains a fragment of an old ecosystem to aid the imagination in this regard. There, just a short walk from Meguro Station, this 200,000-sq.-meter patch of forest and wetland remains very much unlike a typical urban park.

Take a few steps inside on a winter’s day and, after following a path cutting through thick bush, the city’s endless swaths of skyscraper simply disappear. In their place a feeling of being immersed in a vital, breathing wilderness takes over, replete with lush evergreens, ponds, fallen trunks, marshes, exposed roots, insects, eerie bird calls, mysterious rustles behind veils of criss-crossing branches and dark earth carpeted in a mosaic of fallen leaves. In fact, the habitats here are so well preserved that the institute has served as an ecological research site for more than 60 years.

“Here we let nature take its course,” said Shinsuke Hagiwara, 65, a recently retired specialist in plant ecology who spent almost four decades at the institute researching, managing and teaching about its natural systems. “In other green spaces in central Tokyo, human beings tamper with the ecologies, but this place has been preserved from long ago with minimal interference,” he declared both pleased and proud.

Parks in central Tokyo of comparable size — such as Rikugien and Shinjuku Gyoen — have all at one point been cleared of brush to plant grass, layered in concrete, razed to the ground in wartime U.S. bombing or otherwise severely impacted by human hands. Yet the ecosystems of the institute have remained relatively intact despite all that and Japan’s rampant industrialization over the last 135 years.

The land in Meguro is first mentioned in records around 1559 as belonging to a certain Lord Shirogane, about whom little is known. By 1664, though, ownership had passed to Zojoji, the Great Main Temple of the Chinzai sect of the Shingon School of Buddhism — from where it became part of the estate of a feudal daimyo named Yoshige Matsudaira. Then, after being managed by the Matsudaira family until 1871, it was nationalized by the modernizing Meiji government for use by the military.

Since the estate was used as a storage site for gunpowder, no landscaping was required and it was spared the tree-clearing that befell many other military grounds taken from daimyo.

In 1917, it came under the stewardship of the Emperor, acquiring the name Shirogane Goryochi before at last being opened to the public in 1949, four years after the end of World War II, as the Institute for Nature Study. At that time, the national government assigned it the designation of a “natural treasure” — meaning all logging, brush-cutting, plant-trimming and other tampering with natural processes was forbidden.

So, while not entirely untouched, as a result of this distinctive history the ecologies on the institute’s grounds today do have an unbroken genetic continuity with organisms of the past.

“It might seem dirty, but we want people to see that there is real nature even in the middle of Tokyo — rotting trees and all,” said Hagiwara.

“Humans think they are superior to nature and can shape it into whatever they please, as they do at other gardens in the city. But in reality, nature is far more ingenuous than us; we are clueless how to deal with all our garbage, but nature keeps on recycling its own waste totally unassisted by us,” he pointed out. “Rotting trees are eaten by bacteria and insects to become soil, which in turn becomes nutrients for plants. In this way, nature has maintained its own life cycle for aeons. This is what the institute teaches us.”

Now home to more than 236 kinds of trees, 1,400 kinds of plants, 2,800 kinds of insects, 13 kinds of fish, 12 kinds of mammals and 20 kinds of amphibians, the institute can certainly lay claim to an astonishingly abundant biodiversity in its mere sliver of urban core.

In fact, several species of flower there can be found nowhere else in Tokyo — such as hamakusagi (Premna japonica), tamushiba (Willow-leafed magnolia) and yukiwarichige (anemone kaiskeana). A few — including torano-osuzukake (Veronicastrum axillare) — are even endangered, along with some of the orchid found there.

Moreover, since the regulations took effect in 1949, the number of trees of at least 10 cm in diameter has increased more than fivefold, from 2,000 to 10,899, whereas the population of invasive species that prefer bright places, such as the Western dandelion, has dramatically declined, deprived of light by the thickening canopy.

Given that ecological systems are in constant interaction with their environment, the walls around the compound cannot fully protect the interior from the encompassing metropolis. For example, vehicle exhaust fumes eliminated numerous Japanese red pines in the 1960s when emissions peaked. And although modern regulations have brought pollution levels down, the red pine have never recovered since they compete poorly in a fully developed forest.

Global warming has also left its mark. Not only have leaves begun to change some two weeks later in the fall, just as flowers are blooming earlier in spring, but palm trees have multiplied rapidly over the last several decades. Previously, their seedlings could never take root because the soil would freeze in winter and they’d be killed overnight. But with an increase of 5 degrees in the low for January over the last century, the temperature at which soil freezes — just below minus 4 degrees — is no longer reached, and young palms can now survive.

So, when seeds were winged into the reserve by brown-eared bulbuls in the early 1960s, the plants began to proliferate until, by 2010, there were 2,281 in total.

Meanwhile, although it’s not a process that’s been very well studied, the institute clearly exerts an influence on the city as well. In climate discourse, it’s not unusual to hear the term “heat island,” which refers to an isolated area that accumulates and traps heat more than its surroundings. But Hagiwara claims the institute has the opposite effect: “This place is a ‘cool island’ because it has a lower temperature than the city around it,” he explained. “As a result, cool air drifts downwind from here toward lower elevations at night and people living in the vicinity say their air-conditioning costs are half those of friends in similar properties further away.”

So does a visit to the Institute for Nature Study help us imagine what the natural landscape of Tokyo originally looked like? Having sustained an unsevered link with ecosystems of the past, it probably does, yet just how far it can take our minds is hard to say, considering its many permutations over time.

In the last Ice Age, which ended around 12,000 B.C., the forests of this region comprised subarctic conifers, and when temperatures rose afterward, broad-leaf deciduous forests appeared. However, when settlers called the Yayoi arrived from mainland Asia, they felled much of the tree cover to create a relatively bare plain that came to be known as Musashino.

After that, it wasn’t until the Edo Period (1603-1867), when the shoguns ordered the planting of trees and forbade logging that the region was finally greened again. Hence the ancient trees to be seen on the institute’s grounds — including those named the Monogatari-no-matsu (Story Pine) and Orochi-no-matsu (Great Snake Pine) — are thought to have been planted in that period.

Moreover, the once-ubiquitous pines have been diminished by pollution, and palms, which never grew wild here, are on the rise. In short, there does not seem to have ever been any stable state of “aboriginal” nature to imagine in the first place.

Nonetheless, perhaps the Institute can help us imagine something else. “If you knocked down the buildings and didn’t interfere for 200 years, something resembling this place would appear,” said Hagiwara. “It’s actually better not to plant trees because that can disrupt the unfolding of nature. First grass sprouts up, then weeds, then brush. That sequence helps the ecology to mature.”

So not only does the Institute provide a way to trace backward into Tokyo’s ecological past, perhaps it also helps us to imagine what the metropolis might become without us in due course.

  • islisis

    lovely article, another reason why tokyo has a bit of everything…

  • Vasu Seshadri

    Thanks for an eye popping experience of the old contrasting with the new for gaijins who would never have ventured into the concrete jungle of Tokyo.