Thinning (BMI) in Niiharu

Every activity day morning, the volunteers of Lovers of Niiharu Citizen Forest gather at Ikebuchi Hiroba where the to-do list of the day is on display in a small blackboard. Using the Niiharu Conservation and Management Plan 新治保全管理計画and considering the discussions at the Niiharu Council 新治保全管理協議会, the weekly menu is decided by the annually elected executive members of the Lovers. The first thing each volunteer should do when we arrive at Ikebuchi Hiroba is, to write our name in the attendee list (for insurance purpose), and to choose which activity we are going to do out of the list. No order or request will be issued from anybody. If you find no activity is attractive, you can leave the place without saying goodbye. (Well, no one would do so, after venturing into the Forest this far.) The regular activity in the list is “Patrol.” When we patrol, we pick up trashes along the trekking roads, and check if the routes are safe for visitors. Volunteers are encouraged to join a patrol group once in 3 months at least, and prepare a written report about the point where we find a work is necessary. The executive board collects the information and plans the next activity to list in the menu. As Lovers meet at least once in a week and the information of morning patrol can be utilized in the afternoon in some cases, the maintenance work of the trekking road in Niiharu is very quick and probably more efficient than reporting the problem to the City. One thing the lecturers of the Forest Volunteering 101 emphasized last fall was the power of volunteers who could take care of the forest in a careful and effective way. Patrolling and maintaining the trekking route is one example for that. One way to maintain the road safe is to remove protruding branches and unstable trees close to the public access. The leader of the Lovers of Niiharu Citizen Forest, Mr. Ohkawa, emphasizes every morning meeting of an activity day that careful pruning and thinning along the trekking roads are the priority in order to keep the Forest safe.

Plat du jour

We do “Radio Work Out” every time before starting forestry.

Patrolling

According to Niiharu Conservation and Management Plan, winter is the best time to thin trees. Vegetation is dormant so that cutting gives the forest the least stress. Hence, the volunteers for Lovers of Niiharu Forest are very busy from December to February with chainsaws. The Lovers for Niiharu has (really) an army of chainsaw wielding amateurs. In Japan, it is illegal to operate chainsaws without license whose basic level requires more than 10 hours of lectures and labs + the final exam presided by accredited organizations at the cost of min 12,000 yen. Though the Lovers organization subsidizes the cost partially (“thank you Green Tax!”), acquiring and advancing the skill is not at all cheap. The existence of chainsaw troop is a proof how much the volunteers are enthusiastic ... of course for improving the biodiversity in our city, not just to cut trees! ;)

Our dear chainsaws …

After joining the Lovers a couple of months ago, I’ve already witnessed many thinning. Last month, I’ve posted my experience during the Winter Kids’ Festival in a bamboo forests in Mukaiyama, near C-2 and C-3. Mukaiyama is in Zone A whose mission is to provide educational experience for traditional co-habitation of nature and humans in Japan. So, the forest was chosen for kids’ playground. Yeah, it was a kind of cute job, but it made a serious sense. About 20 groups of kids cut one bamboo each in about 5,000 m² forest. According to the Plan, the optimal distribution of bamboos is one tree per approx. 4 m² so that that this particular bamboo forest can have 1,250 bamboos. 20 bamboos thinned during the Festival are about 2% of the optimal number. Too little? Well, the festival was on the first Sunday of February, and the optimal thinning season for bamboos is December and January. Unlike the other kinds of forest, bamboos require annual thinning and the Lovers already did some work beforehand this season. Actually the kids provided a final touch for the annual job.

Every hand counts!

Lovers of Niiharu thin and prune in the Forest according to the Niiharu Plan. The reason of the work is not contained simply to restore the Satoyama forest. A-6 point is called Maruyama which is in Zone A whose mission defined in the Plan is to popularize Satoyama concept. It was once a garden of Mr. Okutsu who installed many fun things in the area including his own hand-curved sculpture. The place is in the middle of the popular promenade connecting Ikebuchi Hiroba 池ぶち広場 (A-7) and Miharashi Hiroba みはらし広場 (A-4). i.e. Many people come. Probably unintentionally, Mr. Okutsu left several wires connecting trees in the area. Now the trees in Maruyama are large and the wires were dangerously pulling the trees each other at a very high place. Luckily, the trees in Maruyama are broad-leaved trees that requires once in 10-15 years coppicing. So, this year Lovers volunteers cut these trunks with wires before a serious incident happens.

Maruyama with the woodwork
by the late Mr. Okutsu

Before coppicing.
The trunks with blue tape were coppiced
for the safety of visitors.

In February, the volunteers pruned the plum boughs in an orchard in Mukaiyama that can be admired from the Okutsu House. Unlike peach, cherry or almond, plums have branches that grow towards the trunk, which creates geometrical beauty. Moreover, plum is so vigorous that its branches shoot out a lot in every spring and summer. Messing the timing and volume of pruning, we’ll have a sorry plum tree with jumbled branches with few flowers and fruits. Annual pruning season for plums is after the rainy season, in July, when we should cut the branches aggressively by leaving about 10 pencil-sized new branches from a bough. Next spring, the plum flowers will come a lot only on these branches at about 10-20 cm from the bough.  In addition, after several years of the standard treatment, we need to thin large boughs during winter in order to lessen the stress on a tree. This year ladies of the Lovers enjoyed hand pruning of plum boughs with lots of flower buds with noble scent. Many brought home the pruned branches for flower arrangement. Come to think of it, there are lots of Ukiyoes for plum blossoming party of ladies ...

Plum tree orchard after pruning

And here comes the important fact of thinning / pruning / clearing forest. After the cutting there will be literally tons of woods, obviously. What should we do with them? Utilizing lumber for woodworks … harvesting logs for fuels of stoves … flower arrangement? It seems to me this is the most difficult part of Niiharu volunteering. The Plan said we should not clear the ground completely anytime. Some remnants of the trees / grasses must be left since they can provide something (shelter, nutrition …) for the other living creatures, and could contribute to the maintenance of bogs by creating the corridor of soil movement from the hills. But when we leave all the cut woods to be rotten, they covered the ground completely and the new growth of dormant seeds underneath is deterred, or worse when the woods host plant diseases. We must take them, the majority of them, out. Oh, by the way, this being in a protected Forest, the work must be done without gasoline engines. A-mano, OK?

Carrying branches from the field

The mountain of cut branches
after the ladies kept the bounty

The pruned plum branches were gathered and transported to a designated field near the Visitor Center where the specialized garbage collector will come to pick them up. The City has a green recycle plant next to Zoorasia. It produces wood chips from pruned and thinned trees harvested mainly in the municipal parks. We loaded the plum branches on a small truck, and the car run 2 round trips to the collection point to complete the job. I guess the plum branches were brought to the recycle plant. The mission accomplished. (Applause.)

Plum brunches were cute, honestly.

Thinning could be a part of collaboration with another organization at the Niiharu Council. Many members of the Association for Niiharu Bounty Community新治恵みの里準備会are elderly folks. Although they are active enough to plough their land for commercial agriculture, their business is often a single senior citizen operation. Their land is every so often surrounded by a private forest of coniferous trees which were planted in the 1940s. More than 70 years of neglect has made those trees huge, with invasive undergrowth. The farmland is not only deprived of sufficient sunshine, but also threatened by spread of shrubs. From Niiharu Citizen Forest’s point of view, even if the problem forest may not be within the border of the Citizen Forest, the situation is happening at the perimeter that will soon bring degradation to the Citizen Forest. The elderly Association cannot treat the problem by themselves, and here comes the Lovers for rescue.

Everybody loves sunshine.

Early March this year, the Lovers volunteers cleared a part of the south facing slope of Mukebara that is next to Zone C where the mission of the Forest is to preserve the natural ecosystem. The place was on the edge of a forest of quercus serrata and a forest of chamaecyparis obtuse / Japanese cedara cryptomeria. Before the work, the slope was populated by Japanese cypresses with 60cm+ of diameter and 30m+ tall. They were planted more than 70 years ago for commercial purpose. Many years have passed since domestic lumbers became uncompetitive against imported woods, and the trees in Mukebara were left uncared that made the trees less and less valuable. Then, the landlord of the farmland at the top of the slope became seriously ill, and no longer able to till the place, or to plan for the work of the cypresses. He rented the place to his neighbor who is now an abuelita in her 70s. She found herself taking care of the land with increasingly scarce sunshine and encroaching bamboo grass. She called help. Lovers with chainsaws were thrilled, of course. They cleared the slope of approx. 50m wide. The objectives of the operation were

• To restore the sunshine and the space for the farmland of the abuelita;
• To utilize the wood harvested from the slope;
• To prepare the slope for hosting mantle vegetation that will protect Zone C. 

And woods? How about woods after cutting? … 30m freshly cut cypresses with 60cm diameter to be pulled from the valley by hands?

Mukebara area seen from A-2 to the south.
It is a typical Satoyama scenery of Niiharu
with the surrounding forest.
The trees immediately next to the farmland
stand outside the boundary of the Citizen Forest,
but it continues to the protected Forest without any barrier.
So, ecologically they are a part of Niiharu Citizen Forest.

The machines are unloaded from the truck. Let’s work!

Cleared slope

The tree was unattended for so many years
and its core is rotten,
which made the tree not commercially valuable.

A cypress without pruning became gnarling.
Volunteers agreed it would be a useful material for artists,
but a junk in construction business …
besides, who knows if it keeps its aesthetic form after drying?

This one will be processed for lumbers
to remake picnic benches in Niiharu Citizen Forest.
By the way, Mr. Ohkawa taught me
the skin of cypress like this would have been
a very good material for the base of roof tiles
covering traditional Japanese houses.
Now, no one bothers. *sigh*

Beautiful … it will be a good bath-tub!

For your information, they are HEAVY.

It took 2 whole days to bring half the cypress woods out of the valley, and as of March 20 the other half is still lying on the slope. What we did was

1. on the slope, slicing huge woods into about 2 to 3 meters long,
2. putting  2-3 ropes around the trunk, secured, aaaaaaaand,
3. pulling the trunk by hand.

The work will be continued until the field above the slope is cleared and some of these woods are turned into tables and picnic chairs. Please stay tuned how the volunteers manage this project …

Equipment for human cranes

The thinner parts of cypresses were brought up first
and were moved near to the road
for making a space to larger trunks.
All by hands, of course.

Slicing the log

Rope it, then …

The human power

It comes this far!

Job half done

After today’s job,
the tune-up must be followed for chainsaws,
even if you are exhausted.

If you plan to spend money for using equipment in a gym, think again, and join our Lovers’ activity. The weight we had to pull was NOT a joke. We thinned the forest, and I believed I thinned my BMI. Unfortunately, the weight scale of mine very coldly notified I lost only 100g on that day. *sigh* 

Phoosticks in Umeda River

If you find a problem in the Niiharu Forest, please make a contact with

Office for the Park Greeneries in the North 北部公園緑地事務所

Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局

Phone: 045-311-2016 (I guess in Japanese only)

FAX: 045-316-8420 (I hope there is somebody who can read English …)

Niiharu Administrative Office / Satoyama Exchange Center 新治管理事務所・里山交流センター

Phone: 045-931-4947

Fax: 045-937-0898

Email: info@niiharu.jp

http://www.niiharu.jp/