Published papers

In this paper, we conducted a field experiment on a large park which is located on the north part of Awaji Island, central Japan, in order to verify effects of mulching of wood chips made from pruned braches and leaves on 39 cherry trees (Cerasus × Kanzakura 'kawazu-zakura'). 39 trees were divided into three groups: wood chips were laid around 14 trees after grass removed, sand was laid around 15 trees after grass removed, and 10 trees were treated as control. SPAD value, photosynthetic rates for tree growth, and soil temperature and moisture were measured from the beginning of August to the middle of November. As a result, the average of soil temperature of tress with wood chips was significantly lower than ones of trees with sand and control trees. The averages of soil moisture of trees with wood chips and sand were significantly higher than one of control trees. Also, trees with wood chips and sand had significant higher SPAD values than control. The photosynthesis rate of trees with wood chips was less reduced than the others. These results showed that the multing of wood chips could keep trees healthy, because of maintaining the soil temperature and moisture.

Water quality and fluctiation pattern in water level of 38 small irrigation ponds were investigated in Hokudan- cho, Hyogo Prefecture, West Japan. Temperature, water temperature, pH, electric conductivity (EC), dissolved oxygen (DO), N02-, N03- NH4+, SiO2, PO43-, chemical oxygen demand (COD) and water level were surveyed in each pond from May 2002 to April 2003. The result showed that there was not so much difference in water condition of among ponds, because water is frequently pumped from a pond to another pond. The existence of water plants and polluted water from residences influenced water condition. The water level of most irrigation ponds fluctuated dramatically from spring to the end of summer.

I am researching the Aso region to clarify the multilayered area of the regional circular and ecological sphere and the method for its construction. The largest area is the basin of six class A rivers flowing down from the Aso region as a regional circular and ecological sphere. Approximately two million people live in this basin, and 2.3 million people in the Fukuoka metropolitan area also use its water resource. The population of the Aso area, which is the source of the water, is about 210,000, and it is estimated that the population will be reduced by half by 2050. In the Aso area, there are more than 20,000 hectares of semi-natural grasslands, which play a significant role as a groundwater recharge area. The area of the grasslands is decreasing year by year due to the aging of the people involved in maintaining and managing them, and it is predicted that more than half of the grasslands will be lost by 2050 compared to 2003. To halt the decline in grassland areas, it is necessary to reduce the amount of labor required for burning at the end of winter.

During the depopulation era, the revitalization of rural mountainous areas that continue to shrink is a pressing problem. Under this severe circumstance, it is an essential task for design rural management policy to clarify the mechanisms of development of a vigorous region and construct the support systems for these regions, meaning constructing promotional systems for endogenous development. In this research, we conducted a field survey at Shunran no Sato, where local residents tried to revitalize the village by farm-inn and urban-rural exchange, and to evaluate the significance of consensus building in local development. In this area, the local development was founded upon an agreement by only seven persons under a time pressure to build a consensus. Through consensus building, this area could achieve revitalization even though on the verge of extinction by remarkable depopulation by means of obtaining official support and having the cooperation of local residents. In this paper, we review the merits, demerits, conditions, and important points underlying a prompt action of a rural activation project based on partial agreement for the local, endogenous development. As a result, it was clear that, although partial consensus building prevented the residents and region from various potential losses, it did not prevent some conflicts, specifically those that occurred early in the program. However, the core organization was careful to avoid conflicts. Overall, the style of regional planning in this area was good in terms of avoiding a conflict in early stages and establishing an incentive design in its developing stages. However, we must beware this report's findings, because making light of consensus building corresponds to an abuse of a precautionary principle. As such, to accomplish partial consensus building for the prompt action toward local revitalization, it is necessary to first base the scenarios on rational basis that indicate that the area cannot avoid failing if residents don't agree.

I investigated birds from 15 January to 24 February 2004 along 8 wooded streets in central area of Osaka, Japan, in order to determine which environmental factors of wooded street are important as habitat of birds in winter. Eight species of 218 individuals were recorded at 2 times observation of the streets. I used a satellite image to identify the distribution of vegetation in my study area. The normalized difference vegetation index (NDVI) of each grid cell was calculated. The value of NDVI that indicated the threshold value for vegetation cover were 0.3 and more, based on the ground-truthing from December 2003 to February 2004. The proportion of vegetation cover within 50 m from a recording point was calculated in each bird species. The average vegetation cover proportion of Hypsipetes amaurotis and Sturnus cineraceus was more than 25 %, while that of Passer montanus was around 5 %. Almost all individuals of species except Passer montanus were significantly recorded in buffer areas within 100 m, 200 m, 300 m and 400 m from the edge of 2 ha and more woodlot.

1970年代にバイエルン州で初めて作製された生物空間地図は,その後ドイツの自然保護において,必要不可欠な資料として位置づけられ,ドイツ各地で作製されるようになった.地図作製手順には,当初から大きな変更がないものの,具体的な作業方法は大きな変化を遂げた.一般的だったカラー空中写真にかわり,最も重要な基礎資料として赤外カラー空中写真が利用されるようになった.地理情報システムの活用によって,情報はすべてデジタル化され,コンピュータ上で地図が作製されるようになった.本論では,最新の地図作製方法とその応用について紹介するとともに,我が国における生物空間地図を生かした生物多様性保全のあり方について検討した.