農村都市協働による有機農業の生態系サービスの評価および価値創出モデルの検討
早稲田大学人間科学学術院 天野正博
特定非営利活動法人 霜里学校
特定非営利活動法人早稲田環境市民ネットワーク

１．目的
埼玉県小川町の下里集落は、1971年に有機農業を開始した金子美登氏（霜里農場）を中心として、2003年より集落全体が有機農業への転換に取り組み、「有機の里」として知られている。また、有機農業従事者は農地に近接する里山の落ち葉を堆肥利用し、農用林として利用している。その集落でも高齢化や耕作放棄地など、里山・農地の維持・管理に課題を抱えている。
本研究では、NPO法人霜里学校が霜里農場や地域住民と協働し、有機農業をテーマとした農業・加工・里山体験・下里分校の活用、都市・農山村交流などの活動を行い、環境保全に取り組む。
一方、埼玉県本庄市大久保山は、早稲田大学のキャンパスとして40年間放置されていた。近年下草の管理は行われるようになったが、里山としての利用は、早稲田環境市民ネットワークらによってごく一部のエリアでの落ち葉利用が行われているに留まる。この対照的な２つの里山の生物多様性・炭素吸収量を比較調査することで、下里集落の生物多様性、生態系サービスを明らかにし、農業体験や貸し農園に参加する交流者などを対象に、有機農業の環境保全への貢献や生物多様性の価値を学ぶプログラム、有機農業への支援の意識向上手法を開発する。

研究・活動の状況
２）有機農業と里山保全の市民参画・理解促進活動

１）生物多様性調査・炭素吸収量調査

フォーラム・勉強会

下里地区の長期管理区（M40）における炭素循環

9月14日下里公開フォーラム

12月12日板橋区勉強会

地域住民対象に、有機農業と里山保全が地球環境保全に繋がることの講義、都市住民対象の農村に都市住民が関わる意義の講義・ディスカッションが行われ、以下のワークショップへと繋がった。

里山の管理と収穫物の利用が炭素収支に与える影響

ワークショップ

1月10日
落ち葉かきワークショップ 3月12・13日炭焼きワークショップ

落ち葉等のエネルギー利用を行わない場合、炭素放出となる全てのワークショップに地域・都市住民が参加し、地域課題となっている林道の落ち葉、林地残材を活用したプログラムを構築した。

３）まとめ
市民の「有機農業」「生物多様性」に対する意識としては、アンケート結果や勉強会での議論から、単純に生物多様性を目的とするよりも。都市住民の関わり方として、落ち葉・薪炭燃料を活用したイベント（焼き芋、炭焼き）等によるレクリエーション機能を強調して結果として「有機農業」「生物多様性」 へ繋げることが効果的とでた。里山管理の環境影響についての調査と併せ以下の表にまとめる。
●生物多様性の調査
小川地区の里山林で林床の植生調査を行い、対照区に比べ40年管理区の林床植生の多様性が高いことがわかった。
ただし、下里地区にはカタクリ・ニリンソウ群生地が保全されているが、40年管理区の光環境は4月上旬以降急激に光量低下し、これらの植物には厳しい環境となっている。希少植物の生息環境向上や、雑木の生長によるCO2吸収の視点では40年管理区においても本数管理が必要であると考えられる。

Assessment of Value Creation Model and Evaluation ofEcosystem Services of Organic Farming through
Rural-Urban Cooperation
Masahiro Amano, Faculty of Human Sciences, Waseda University / NPOshimosato-Gakkou / NPO Waseda Environmental Citizen Network

Objective:
The community of Shimosato in Ogawa Town, Saitama Prefecture is known as an “organic community” because of its initiative since 2003
in which all farmers switched to organic farming led mainly by Yoshinori Kaneko (shimosato Farm) who first began organic farming back in1971. Organic farmers collect litter from the neighboring SATOYAMA as compost, using it as an agro-forest system.. The community also
faces the problem of maintaining and managing its farm land and SATOYAMA because of its aging population and idle farm lands. Under thisresearch project, NPO Shimosato-Gakkou works with shimosato Farm and community members to carry out various activities for environmental
conservation, such as farming, processing products, and experiences of SATOYAMA activities based on the theme of organic agriculture, use of
Shimosato branch school, and events where people in urban and rural areas can meet and mingle.
Meanwhile, Okuboyama in Honjo City, Saitama Prefecture had been left untouched as a campus of Waseda University for a span of four
decades, but in recent years, management of in Okuboyama has taken place. Its use as a SATOYAMA is limited to the utilization of litter fromonly a small portion of the forest by the Waseda Environmental Citizen Network. Through studying and comparing these two contrasting
SATOYAMA based on their biodiversity and carbon cycle, this project seeks to shed light on the biodiversity and ecosystem services of
Shimosato and create a program for people taking part in experiences of farming activities or farm lending to learn about the value ofbiodiversity and contribute to environmental conservation of organic farming, and to develop a method to raise awareness about supportingorganic farming.

Status of Research/Activities

2) Activities to promote understanding and civic participation inorganic farming and Satoyama conservation

1) Biodiversity Study / Carbon Absorption Volume Study
Carbon cycle in the long-term management district (M40) of the shimosato area
Harvested crops = 2.62

Forums/Seminars

Soil respiration=8.39

Atmospher

Pure primary production=8.11
Reaping = 0.21

Plant respiration=1.87

PlantsHumanFallen leaves/Withering=4.47
Raking fallen
leaves = 2.41

Litter/Dead organisms

Soil organic
matterFossil fuels

Forum in shimosato open to the public(Sept. 14)
Microbial respiration=6.52

Lectures that combination between organic farming and Satoyama managementwith the larger theme of global environmental conservation were conducted for
local residents, while lectures and discussions on the attitudes of urban residents
in agricultural communities were conducted for urban residents. These were thentied in with the following workshops.

Impact of Satoyama management and use of harvested crops on carbon balance

Net primary
production

Breathingof soilorganismsCarbonemissions fromharvested
crops/biofuels

Net ecosystem production (NEP)
Volume of fossil fuelreduction

Crop isolation(unused/un-brokendown)

Breaking
down/combustionof harvested crops(wasteful use)

40-year management district

Dominance ratio

Dominance ratio

workshops

Use of harvested
crops asbioenergy

・As energy use is not applied to fallen leaves, etc., carbon is emitted.
Compared district

12 December: Study session in Itabashi Ward

10 January
Workshop on raking fallen leaves

Both local and urban residents participated in all workshops, and programs
were established for the local issues of raking fallen leaves on woodland paths
and the utilization of forest scrap.

3) Summary
With regard to the attitudes of residents toward organic farming andbiodiversity, based on the results of the questionnaire and discussions at theseminars, it was found that instead of simply establishing biodiversity as thegoal, it would be more effective to place the focus on recreational functions(including events that make use of fallen leaves and firewood fuel, such as
baking sweet potatoes and making charcoal), and then ultimately tying these inwith the themes of organic farming and biodiversity. The summary is shown in
the table below, alongside with the study on the environmental impact ofSatoyama management.
CO2 absorption● Study of biodiversity

A study was conducted on the vegetation on the forest underfloor of Satoyama in theOgawa district, and the 40-year management Satoyama revealed a higher level ofdiversity in the forest underfloor vegetation than the compared unmanaged forests.
However, although colonies of Erythronium japonicum and Anemone flaccida areprotected in the shimosato area, the amount of light in light environments in the 40year management forests falls rapidly after early April, creating a harsh environment
for these plants. It is believed that there is a need to control the number of plants in the40-year management forests as well, from the perspective of improving the habitats
for rare plants as well as CO2 absorption through the growth of scrub.

12/13 March
Workshop on charcoal-making

UnusedSatoyama(× if grown forest)

UsedSatoyama(↑ Research topic)

Biodiversity

Recreational
functions ofallotment gardens