Planting trees for hugging them … is not so simple, mate

Niiharu Citizen Forest is one of the Satoyama representations in Yokohama. Satoyama 里山 means “Sato = where humans live daily lives” + “Yama = hill or mountain.” So, Niiharu is a place where ordinary Yokohama people have lived our lives for millennia within a typical Japanese environment. In Satoyama, people used to harvest logs for fuel, leaf mold for rice paddies / veggie field, bamboos for kitchen gadget materials, and any other goodies like wild silk cocoons, walnuts, and berries. The most trees and bamboos there were intentionally planted generations ago by our ancestors. The place has been very familiar. When developers planned to construct condos and detached houses, Satoyama was naturally the first target to bulldoze. The rapid disappearance of greenery in the city of Yokohama has occurred in Satoyama. …

In a fine October weekend afternoon,
a bonfire from rice straws was made in Yatoda rice paddy in Niiharu
by the volunteers for the Group of Protecting Niiharu Yatoda
新治谷戸田を守る会
of the Organization for Promoting Niiharu Satoyama Community
新治里山「わ」を広げる会.
 They made ashes from the fire
and scattered the product throughout the paddies
as fertilizer for the next year.
It is a traditional way of growing organic rice in Yokohama.

The other day one of the people from the city office told me when he was young decades ago there was a fierce debate within the bureau about the change in the way of calculating green space ratio. Till then, the greenery was defined as Satoyama and ag land. 40 years ago when half the city was covered by greenery, the statistics consisted of Satoyama, rice paddies and vegetable fields, but no palm trees on the roof of department stores. If the city had maintained the definition that way, the green space in Yokohama could have been alarmingly minute. So, in the end the city decided to include tiny lawn turfs and roof-top gardens of the buildings in downtown to count “greenery.” The currently most cited ratio, 28.8% (2014), to describe the green environment of Yokohama takes in completely artificial “gardens” of shopping centers. If you see Kanagawa Prefecture in Google Earth, you will see about 2/3 of the prefecture is just like Yokohama. The satellite photo of us is a continuation of gray concrete with a bit of green dots here and there … We are living in the age of certain sadness, honestly.

A part of 28.8%

Forest Instructor Training by the Kanagawa Green Trust is for these remaining Satoyama forests, and another 1/3 of the prefecture. 1/3 includes National Park of Hakone, and Tanzawa Semi-National Park. The area also has lots of municipal / private lands. To some extent, the reason they look green from the space is they are not so near to Satoyama. Actually, there is corresponding concept for Satoyama in Japanese, which is called Okuyama 奥山. “Oku” means “somewhere beyond the familiar environment.” It says all, doesn’t it? Even though, especially between 400m and 800m above sea level, Okuyama in Kanagawa Prefecture has lots of artificial forests ... Anyway, during the Forest Instructor training, Dr. Jun Tamura of Kanagawa Natural Environment Conservation Center 神奈川県自然環境保全センター told us afforested or not, forests could have soil conservation function that is a foundation for biodiversity, water source protection, and greenhouse gas absorption. Any forest has its own samsara sans bulldozers … first there is bare earth due to natural disaster such as volcanic eruption or flash flood. As long as there are water and sunshine, the seeds would sprout. They were buried already before the natural disaster, and / or carried by birds, winds, streams, etc. afterwards. Within decades, the originally desolate area becomes very congested with young trees. Eventually, the weaker trees fell down, which lets sunshine to penetrate in the forest floor. The undergrowth will grow between the remaining fittest trees. Over 100 years or more, some trees would die a natural death, whereas the others go strong for millennia.  If we can see such old forest from the sky, Okuyama would look like a mosaic of various tree tops. It is a signal of biodiversity.

The 21st Century Forest of Kanagawa Prefecture 神奈川県立21世紀の森.
It shows a mosaic pattern somehow.
The place is a half natural park for hikers,
and a half forestry labo for scientists working for the Prefecture.
On the left is an artificial forest of coniferous trees
that was created according to the national policy of Japan.
I will report you later Japanese forestry policy,
which I find very intriguing.

In the forests of Kanagawa that are situated around N.L. 35°, the trees which can grow the most easily is for the temperate zone. Up to 800m ASL they should be evergreen broadleaved forests so that the majority of coniferous trees of Kanagawa found below 800m ASL are artificially planted. If not, they are the survivors of Ice Age, like the forest of firs around Oyama Afuri Jinja Shrine. For an artificial forest, the trees planted are often not only the same species but also have very similar DNA, or even clones by cutting. It means the competitions for survival is difficult to occur. Left unattended, the trees grow tall and lanky in a congested field without undergrowth, until their bare soil is washed away by torrential rains and all the trees die simultaneously. On the other hand, when humans thin the forest from time to time, the sunshine reaches to the ground that would stimulate the variegated undergrowth. Then, over centuries, the originally artificial forest can become somehow similar to a natural forest with biodiversity. The key here, according to Dr. Tamura, is how to facilitate the nature to do this job easily.

Forest Instructor Exercise:
learning how to thin an artificial forest of cryptomeria japonica
in Tsukahara Volunteer Field.
This forest near Hakone is a property
of the Prefecture to train forest volunteers.
According to our instructor Mr. Toshio Shiba,
this tree becomes “2 headed”
because when there was a weeding exercise years ago
its growing point was accidentally cut off
and the remaining top 2 branches grew as such.
Oh my …

Between 800m and 1600m ASL of Kanagawa (; the highest point in our prefecture is the peak of 1673m Hirugatake Mountain in Tanzawa), the climate in Kanagawa is suitable for deciduous broad leaved trees such as beeches. So, in order to recover greenery in our community, we can simply plant according to the ASL these species brought from somewhere … right? Wrong. Dr. Tamura and Dr. Hidetsugu Saitoh, both from Kanagawa Natural Environment Conservation Center, told us plants are very local. Take beech (Fagus crenata Blume). In the early 2000s, Prof. Noriyuki Fujii of Kumamoto University found, very intriguingly, the chloroplast DNA of beeches in Hakone differs from the genes of beeches in neighboring Tanzawa. The beeches have anemophilous flowers so that the dispersion of their DNA within the steeply mountainous area is quite limited. Why, then, do they differ in such a small area? Probably at the beginning of the current interglacial period, due to the existence of Mt. Fuji beeches danced a complicated choreography of adaptation to the changing climate. They settled to have a genetic border somewhere around Ohi-Matsuda IC of Tomei Express Way. Corollary: careless artificial planting of beeches in Kanagawa will degrade the natural diversity at the gene level at best, or normally be unsuccessful with withering young seedlings.

Forest Instructor Exercise: Going into the Forest

Forest Instructor Exercise:
planting a sawtooth oak in Tsukahara Forest.
The seedling was from an acorn harvested nearby,
with the funding of none other than Emperor Akihito.
Thank you, Your Majesty!

Throwing the climate change here, the issue becomes more complex. Dr. Saitoh said, “Look, many trees live to a great old age and survive through mini-disruptions, like the 1780s’ or the 1930s’ cold weather. Now we say rapid global warming, but it cannot give us a carte blanche to plant imported tropical trees in Kanagawa Prefecture. The optimal human intervention should be maintenance of the currently known local biodiversity down to the gene level, and let the nature decide how they become 10,000 years later. If the process includes afforestation, we must be mindful about this scientific fact.” Their discourse resonated with the lamentation Dr. Kitagawa last spring about the invasive plants to Niiharu …

How many of them will survive?
By the way, as you can see this planting field is
sealed off by a sturdy wire-mesh fence.
It’s not because of Imperial seedlings,
but in order to fend off the deer.
There is an interesting story about deer and human activities
in Japanese Okuyama forests that I will report you later.

According to the web site of JNCC who is a statutory advisor to the UK government, the entire British Isles (315,200 km²) has recognized 2951 kinds of plants including “casuals = non-natives” (2002). In contrast, Japanese archipelago (378,000 km²) counts 8,800 plant species (Ministry of the Environment, 2008) where 40% of them are endemics. So, probably, Japan must stick to our gun to “Build the Wall” in order to preserve our neighborhood diversity as those professional biologists say. … Oh my Buddha, that’s sounds very contradictory to “globalization ó diversity” common sense. I guess that’s why the forests of our neighborhood are so fascinating. J

The scenery in
Kanagawa Natural Environment Conservation Center

Incidentally, the access from Tokyo to the 21^st Century Forest (in Tanzawa) or Tsukahara Volunteer Field (in Hakone) of Kanagawa Prefecture is, first you go to Odakyu Shinmatsuda Station 小田急新松田駅 which is next to JR Central Japan (yeah, it’s NOT JR East) Matsuda StationＪＲ東海松田駅. For the 21^st Century Forest you can either rent a car at Shinmatsuda Station, or proceed to JR Central Japan Gotenba Line to Higashi-Yamakita or Yamakita Station 東山北・山北駅 to find another rent-a-car booth. To Tsukahara Forest, you can rent a car at Shinmatsuda, or go from Odawara 小田原 (the terminal station of Odakyu) to Daiyuzan Station 大雄山駅 (the terminal station) by Izu-Hakone Line 伊豆箱根鉄道大雄山線 and visit a rent-a-car desk. In either case, we have to drive at least 40 minute to reach to the place of the above photos. To the 21^st Century Forest, there is a commuter bus service from Yamakita Station to the nearby town. The bus stop is about 1h hiking distance from the 21^st Century Forest for sure. Hey, they are “Okuyama.” The Forests are actually a part of popular (and serious) hiking routes for Tanzawa and Hakone ;-)

The map of the 21^st Century Forest of Kanagawa Prefecture

In the 21^st Century Forest

The map of Tsukahara Forest

The contact address for the 21^st Century Forest of Kanagawa Prefecture 県立21世紀の森 is

2870-5 Uchiyama, Minami-Ashigara City 250-0131, 〒250-0131 南足柄市内山2870-5

Phone: 0465-72-0404

Email: k21seiki@ak.wakwak.com

The contact address for Kanagawa Natural Environment Conservation Center 神奈川県自然環境保全センター is

657 Nanasawa, Atsugi City, 243-0121 〒243－0121　厚木市七沢657

Phone: 046-248-0323

You can send an enquiry to them by clicking the bottom line of their homepage at http://www.pref.kanagawa.jp/div/1644/