Environmental improvement operations with Furusato no Mori (local ...

Environmental improvement operations with Furusato no Mori (local forests)
Report 3
Environmental improvement operations with Furusato no Mori (local forests)
Nobuyuki Eto, Hiroshi Otsuki, Emiko Hikino, Kazumi Nishiyama, Keiichi Murano
Environmental Management Department
Within the vicissitudes of global environmental preservation, new detail is emerging on the
role played by "greenery" and "forests." In particular, since the effectiveness of forests in
absorbing carbon dioxide has been acknowledged by the Kyoto protocol, the function of the
forests in preserving the environment is coming to be seen as a crucial measure to prevent global
warming. The reforestation of our living space, promoted by Espec, originates from our desire to
bring about a pleasant environment giving life to the real functions of the forest. This report
presents the soundproofing and carbon dioxide binding functions, two of the most basic
environmental improvement functions of Furusato no Mori (local forests).
1 Introduction
Espec is publicizing environmental improvement activity as a keystone of environmental
management. That viewpoint can be stated as "doing whatever helps to improve the
environment," and in that spirit, the Espec Mic Corporation of the Espec Group has
undertaken the challenge of reforesting our living space.
The actual reforestation of our living space was carried out over three occasions of tree
planting from 1999 through 2001 at Kobe Technocomplex (hereafter, KTC: the Kobe offices
of our company). Our staff and their families, numbering about 1,100 persons participated in
planting approximately 27,000 potted seedlings on 7,500 m2 .
The Kyoto Environmental Measuring Center has initiated field investigations and research
into the environmental improvement functions of this Espec forest.
Fig.1 The Espec Forest
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Environmental improvement operations with Furusato no Mori (local forests)
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2 Reforesting our living space
Furusato no Mori came about as a result of using the forest creation methods proposed and
practiced by Dr. Akira Miyawaki, head of the Japanese Center for International Studies in
Ecology.
Almost all of the forests in the various areas of Japan have been affected by human
intervention. Pristine nature remains only in a very few places such as in the groves of
village shrines. Examining the natural vegetation in those few remaining sites has provided
insight into their essential ecology (potential natural vegetation), and by adopting those
types of trees in tree planting and trying to create regionally appropriate forests, it is
possible to reforest our living space using local trees.
Table 1 shows the distinctive features of this type of forest creation method. This method is
used for the greening of a variety of areas, such as factories and roadways. 1)
Table 1 Distinctive features and advantages of the Furusato no Mori method of reforesting our
living space
Uses potted seedlings 50 to 80 cm tall.
Features Advantages
Dense vegetation is planted (averaging 2 to 9
trees per m 2 ).
Comprised of various types of trees, with an
emphasis on broad-leafed plants with a deep
green luster.
Immediately after tree planting, water
sprinkling is necessary to avoid drying out, but
after conditions stabilize almost no
maintenance is required.
Tree planting is easier than when using
conventional landscaping trees, and a higher
percentage of trees take root. *1 It is also
possible to plant on steep slopes.
It is possible to very quickly form a forest
canopy, *2 which controls the growth of weeds
and prevents the ground from drying out. This
helps reduce maintenance such as mowing.
Unlike artificial forests of cedar and cypress,
these forests do not cause hay fever.
This is a low maintenance system.
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Type of function
Carbon dioxide absorption
Prevention of surface erosion
Prevention of surface layer
breakdown
Moderation of flooding
Water resource reservoir
Water purification
Fossil fuel alternative
Health rejuvenation
Total
Forest area
Monetary value per 100 ha
Table 3 Diverse functions and monetary value of forests 2)
Monetary value of
forests nationwide
1.2391 billion yen
28.2565 billion yen
8.4421 billion yen
6.4686 billion yen
8.7407 billion yen
14.6361 billion yen
226.1 million yen
2.2546 billion yen
70.2638 billion yen
2.5146 million ha
279 million yen
Method of determining value
The value provided by forest carbon dioxide
recovery is determined by the recovery cost
of the same amount of carbon dioxide in a
thermal power generation plant.
The value provided by forest erosion control
is determined by the cost of building dams
to control erosion.
The value of reduced surface area
breakdown is determined by the cost of
hillside construction.
The value of the effectiveness of forests in
reducing the amount of flooding is
determined by taking the adjusted volume
of probable rainfall for 100 years and adding
the depreciation cost of flood control dams
and annual maintenance costs.
The value of the amount of basin reservoir
provided by forest soil is determined by
adding the depreciation cost of irrigation
dams and annual maintenance costs.
The value of water purification is
determined by adding the depreciation cost
of rainwater utilization facilities and annual
maintenance costs.
The value of the carbon fuel alternative
effect provided by wood house building is
determined by the cost of recovering that
amount of carbon dioxide in a thermal
power generation plant.
The value of forest health rejuvenation is
determined by the cost of travel to
appreciate forest scenery.
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Period constructed
Planting surface
area
Constituent trees
Density
4-2-2 Method of measuring noise
Table 4 Summary of the Kashihara Bypass vegetation 1)
Table 5 shows the noise measurement method, and Fig.3 shows the noise measurement
points.
Measurement
section
Measurement
points
Measurement
conditions
Measurements
From 1981 to 1984
24,600 ㎡
Tall trees: six varieties of oak trees
Medium trees: holly, Japanese ubame-gashi oak,
camellia, and spindle tree (Euonymus japonica)
Short trees: rhododendrum glabrius, Japanese
pittosporum (Euchresta japonica), and Eurya japonica
(Theaceae)
Tall trees: 2 to 3 trees per ㎡
Medium trees: 5 trees per ㎡
Short trees: 11 trees per ㎡
Photo 1 Kashihara Bypass
Table 5 Noise measurement method
No vegetation: Grasping the noise damping effect of distance
Low vegetation: Grasping the soundproofing effect of highway
vegetation set out as a row of short trees forming a hedge
Furusato no Mori vegetation: Grasping the soundproofing effect of
highway vegetation created using the Furusato no Mori reforestation
method
Measurements were made at 3 points (0 m, 5 m, 10 m) from the edge
of the roadway, which was the 0 m point, and the vegetation standing
between the roadway and the 5 and 10 m measurement points.
Noise meter: ordinary noise meter; measurement height: 1.2 m;
Frequency characteristics: A; Motion characteristics: fast
Noise was measured seeking equal noise levels from data of times of
vehicular traffic.
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4-2-3 Method of measuring results
Table 6 and Fig.4 show the results of noise measurements. Looking at the amount of noise
damping at the five meter point, we can see that low vegetation achieves almost -0.8 dB
greater damping than at the no vegetation sites achieving damping by distance alone. The
greatest difference was in the Furusato no Mori vegetation, which achieved -7.1 dB more
damping.
In sites mainly composed of the broad-leafed evergreen trees such as Quercus
myrsinaefolia, an evergreen oak found in Japan and China, and other varieties of oak, the
Furusato no Mori high-density vegetation exhibited highly superior soundproofing results.
No vegetation
Low vegetation
Furusato no Mori
vegetation
Environmental improvement operations with Furusato no Mori (local forests)
Fig.3 Noise measurement points
Table 6 Soundproofing measurements [Units: dB]
Actual measured values
Difference from 0 m
Actual measured values
Difference from 0 m
Actual measured values
Difference from 0 m
0m 5m 10m
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76.9
0
76.8
0
77.2
0
69.8
-7.1
68.9
-7.9
63.0
-14.2
66.1
-10.8
66.4
-10.4
61.4
-15.8

Environmental improvement operations with Furusato no Mori (local forests)
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Fig.4 Noise measurement results
4-2-4 Estimates of the soundproofing effect of the Espec forest
At the slope in front of KTC facing the Chugoku highway, the tree height is currently 1 to 2
meters, and there is almost no soundproofing effect. The noise at point A3 in Fig.5 is
approximately 75 dB. If the two rows of forested zones grow well, in 10 years the tree height
is expected to reach 6 to 7 meters. 1) The types of trees composing the forest and the forest
density differ slightly, but if we assume that this will achieve a similar soundproofing effect
to that of the Kashihara Bypass highway vegetation, we can estimate that a single zone of
trees will create a damping of -7 dB, and two zones will achieve a damping of -14 dB.
Fig.6 presents examples of the effects of noise levels on people. In the future, the
soundproofing effect of the forest is predicted to suppress the effect of vehicular traffic noise
and create a pleasant work environment surrounded by the forest.
Fig.5 Soundproofing effect of the Espec forest
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Environmental improvement operations with Furusato no Mori (local forests)
Fig.6 Noise evaluation
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6 Conclusion
We have presented trial calculations demonstrating the soundproofing effect and the
amount of CO binding by the Furusato no Mori. Our investigation into this matter is still in
2
its initial stages, and we plan to carry this inquiry forward.
Within the New Climate Change Policy Programme decided upon in 2002 to be promoted to
counteract global warming, one of the countermeasures put forth was to promote the
greening of cities. We would be delighted to have our readers consider the method of
reforesting our living space as an activity contributing to society in the area of
environmental management.
7 Acknowledgements
We are grateful for the valuable advice we have received from Professor Kazue Fujiwara of
the Graduate School of Environment and Information Sciences, Yokohama National
University.
[Terminology]
*1 Percentage taking root
The percentage of tree seedlings that take root after planting
*2 Forming a forest canopy
The leaves and branches of the forest form a complete canopy, and light cannot reach
the forest floor.
*3 Amounts of CO bound
2
The amount of forest existing for a given unit of surface area at a given point on a time
axis. This generally forms a logistic curve.
*4 Trunk lumber volume
The volume of the tree trunk
[Bibliography]
1) "Theory and techniques of creating forests for environmental preservation," Japanese
Center for International Studies in Ecology, 1995
2) "Evaluating the multi-faceted functions of agriculture and forests in relation to the global
environment and human life," The Science Council of Japan, Nov. 2001
3) Akira Misawa, "The function of roadside greenery: the structure and impact of an
environmental green belt," p.41-63, 1995
4) Yasuo Tokita, "The environment and control technology of sound: Vol.11, applied
technology," Fujtec Corporation, p.751-780, 1998
5) "Reforestation manual for atmospheric purification," Council on compensation and
prevention of pollution health issues, 1995
6) "Tables of trunk lumber volumes in standing trees -West Japan edition-," J-FIC, 1998
7) Kazue Fujiwara, "Mid-term report on research into the environmental purification
functions of forests for environmental preservation in plants such as iron mills," Jan. 31,
2001
8) Kazue Fujiwara, "Research into the environmental purification functions of forests for
environmental preservation in plants such as iron mills," 2002
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