TAKASHI OYABU

VR (head-mounted display) is a tool that allows you to experience a three-dimensional space. By using VR to evaluate green spaces, it is possible to evaluate them as if they were real spaces. In this study, we aimed to understand the spatial recognition characteristics of VR images of green spaces, and focused on the understanding of spatiality, the reproducibility of reality, and the effectiveness of the montage method. The method was to evaluate green spaces using VR, photography, and field evaluation, respectively, and compare the results. First, we compared the VR evaluation with the photography evaluation in terms of spatial understanding. As a result, we found that VR is superior to photography in expressing three-dimensionality. Also, regarding the reproducibility of the scene, we found that VR is superior in recognizing close view and middle distance view, and that there is a tendency for the difference in evaluation to be greater in sunny weather than in cloudy weather. In addition, when we showed the montaged images in VR and photos, both showed similar reactions regarding variability. Therefore, it can be said that the use of VR in the evaluation of green spaces is suitable for the evaluation of close to middle distance view and evaluation in fine weather.

In order to understand changes in the use of bamboo forests by wild boar, the count of the bamboo shoot feeding marks by wild boars, the position of culm, diameter of culm and a stand age-structure survey were conducted in Awaji Island from 2017 to 2018. Edible bamboo shoots appear on the ground in spring, but we found that wild boar has dug the soil and eaten bamboo shoots before the end of October. In November the number of eaten bamboo shoots accounted 0.1 to 0.7/100m²/day. The total number of the eaten bamboo shoots reached 10 to 15 /100m² during this month and this value was almost equal to the number of current-year culm appeared in the next spring. It is considered that wild boars severely affected to the regeneration of bamboo forest.

Midday transpiration rates and daily pan evaporation from forest floor and open area were measured to determine an effective way of controlling water loss from a Melia volkensii plantation. The research was conducted at an M. volkensii plantation in Tiva Pilot Forest, Kenya, during April and May 2014. A leaf porometer (LI-1600) was used to measure midday transpiration rates per unit leaf area (Ta) from 11: 00 h to 13: 00 h for four trees at three different leaf heights: top (A), middle (B), and bottom (C) layers of a crown. Midday transpiration rate per layer (Tl) and midday transpiration rate per tree (T-t) were estimated based on Ta and leaf area (LA) of layers. Daily pan evaporation from forest floor and open area were measured using 25 and two evaporation pans, respectively. Ta values for layer A were not significantly different among sample trees, while Tl values for layer A were significantly different, indicating the influence of LA on water loss through transpiration. Since Tl from layers B and C accounted for half of Tt, pruning of these layers could cause a 50 % reduction in water loss through transpiration. Daily pan evaporation in the plantation was approximately 70 % lower than that in the open area. Therefore, the layer A left after pruning should keep water loss through evaporation from the forest floor lower than that from the open area. Further research is required to determine the effect of pruning on reduction of water loss from the plantation.

Myriophyllum aquaticum is an invasive alien aquatic plant and causes many problems such as water pollution, elimination of native plants, and obstructs water ways. To prevent these problems, suppression of M. aquaticum has been often implemented by local governments and/or NPOs. However M. aquaticum regenerate rapidly and suppression is not effective. In this study, to establish a method for eradicating M. aquaticum, vegetation and population surveys and test extermination were carried out in the field, and shading experiment took place in the laboratory. M. aquaticum covered the whole of the pond, but it rooted only on the shallow area near the waterside. During the laboratory shading experiment, M. aquaticum individuals survived the darkness for 158 days, but the length of M. aquaticum stems decreased through that period. It suggests that shorter fragments of M. aquaticum can die by short periods of darkness. At test extermination in the field, M. aquaticum did not regenerate after shading treatment with soil removed. Most fragments of M. aquaticum were removed with soil, and remnants of fragments were killed by the long darkness period. Exterminating M. aquaticum might be possible by using shading together with removing soil.

In order to prevent the expansion of bamboo forests, possibility of sustainable use of column for fuel and management of bamboo forests on the basis of the estimation of weight and volume of bamboo culm was investigated. The column density, raw weight, dry weight, apparent culm volume and culm volume was 10,460 ha^-1, 247.3t ha^-1, 120.5t ha^-1, 563.3 m³ ha^-1 and 234.2 m³ ha^-1, respectively. The dry weight of culm in Awaji Island was estimated to be 320,599 t. The culm volume recovered in eight years after having felled the bamboo by 50% density. The amount of culm consumption was 2.0t/year when the boiler was used twice a week. It seems that the selective cutting of intervals of 8 year seems to lead the sustainable use and management of bamboo forests.

In this research, we examined the possibility of tree vigor diagnosis by hand-held chlorophyll fluorometer (following, FluorPen) through comparison with the existing measuring method aiming at establishment of the simpler and more objective tree vigor diagnostic technique. Photinia glabra Thunb. were divided into the irrigation treatment groups and the non-irrigation treatment groups, and FluorPen, MINI-PAM, a chlorophyll meter, and visual diagnosis compared the decline degree of tree vigor by water stress. As a result, there was a significant difference by all the measuring methods in the irrigation treatment and the non-irrigation treatment after the 7th day of the experiment start. Moreover, only night measurement of FluorPen had a significant difference between the irrigation treatment and the non-irrigation treatment as of the 4th day.

4 種の造園低木における一酸化窒素を吸収・沈着する機能の定量的な評価を行った。一酸化窒素を 2.0 ppm 封入したチャンバーの濃度減衰時間を測定した結果，葉面積や葉の乾燥重量との関係が認められ，4 種の中ではコクチナシ，キルシェレッド，チェリーセージ，ヒラドツツジの順に NO 吸収速度が速いことが示唆された。

Migration of ferns into six small trenches was monitored for three years in the Natural and Cultural Gardens in Expo '70 Commemorative Park, Suita City, Osaka, Japan. The results showed that ferns migrated into all trenches after three years and that fern migration can be promoted by the development of trenches. The dominant species changed to ferns in the damp evergreen broad-leaved forest stands. However, species composition scarcely changed in the moist, deciduous broad-leaved forest indicating that high-soil water content and the evergreen broad-leaved forest type may be preferable for promoting fern migration. In addition, a preference for a north-facing slope was indicated.

To clarify the current status of irrigation pond abandonment and the problem for aquatic plant conservation, we investigated the percentage of abandoned pond in local area, the relationship between the depth of pond and aquatic and meadow plants diversity at farm village on hilly terrain in northern part of Awaji Island. The investigation was carried out by interviewing 133 pond manager and by field survey. We found half of ponds had been abandoned already, and, we verify the strong correlation between depth of pond and species richness of aquatic plants.

The effects of planting in the city on CO₂ uptake and alleviation of urban heat island phenomenon has received much attention recently. Varieties of general landscape shrubs with improved CO₂ absorbing and transpiration ability have been developed. In this study, differences of the improved varieties and the general landscape shrubs were evaluated by comparing CO₂ absorption and transpiration quantitatively. In the results, Gardenia jasminoides J. Ellis 'Wald' showed 67 % higher growth rate in dry weight, and higher photosynthetic rate than the original. On the other hand, Salvia microphylla 'Kirsch Red' showed high transpiration ability compared with the original.

In this research, we surveyed the formation of wound wood at pruned points by the pruning examination of Cerasus speciosa (Koidz.) H. Ohba in a city park. As a result, the wound wood formed at 87 % of all pruning points, and we considered that the pruning management for C. speciosa is possible in city parks. Moreover, the differences of pruning time did not effect formation of the wound wood and the rate of covering. Therefore, time of after flowered is an appropriate time of pruning to achieve substantial amount of flowering. However, it was suggested that attention be necessary for the diameter of the pruning branch to increase formation of wound wood.

In the biotope " Inochinomori " , fungal fruiting bodies of total 300 species in 45 families were found during 14 years from the establishment. Among them, 283 species were basidiomycetous fungi, and 17 species were ascomycetous fungi. Furthermore, epigeous fungi were 186 species, and the number of species started to increase two years later from the establishment in 1998 with the peak in 2001. Generally, fruiting period was from May to July and September through December. In the early days, Laccaria ohiensis, Hebeloma sacchariolens, and Scleroderma areolatum occurred in abundance, but the occurring number of those fruiting bodies sharply decreased after 11 years in 2007. In terms of species number, many species in the genus Inocybe were found in the early days, but the species composition was started to change to the late-stage species in the genera Cortinarius and Russula from four years after establishment in 2000. These results clearly indicate that the aboveground fungal flora has not remained in early-stage but already changed to late-stage during these14 years.

Shrinkage of the Aral Sea has advanced with development of irrigation. In order to minimize wind-blown sand, plans for afforestation of the dried seabed of the big Aral Sea were initiated. We classified the land cover using satellite image of Terra/MODIS based on truth data of 2006 and analyzed influential factors for halophyte trees distribution by developing a tree model. Halophyte distributed in 24% of the dried seabed while rest of the area was almost salty bare ground. Number of dried years and distance from the old coast contributed most to distribution pattern of them, and appeared to occur on there of over 15.5 years and near the seed source area. However, it did not appear on recently dried seabed. Thus, it would be difficult for the afforestation on the seabed.

This research investigates a process that “The Nippon Plant Protection Society (1913-1943)” ended the society and some projects. In addition, we surveyed the vicissitude of tree treatment methods and associations by literature, especially “The Journal of Plant Protection (BYOCHU-GAI ZASSHI)rdquo;. As a result, tree treatment methods had been transmitted to next generations, but there was no association that had treated trees like the Plant Clinic of the Nippon Plant Protection Society. The cause was that social request had been focused on the value of timber materials for trees. Therefore, researches for increasing the production of the timber materials had priority over tree treatment. In the present time, collecting, verifying the tree treatment technology and transmitting its infor-mation are data of ever-increasing importance for the general public

近年，生物多様性の観点から，在来生物に被害を及ぼす外来生物が注視されている。中でもナルトサワギクは，兵庫県の淡路島および徳島県鳴門市を中心に分布域を拡大しており，外来生物規制法により特定外来生物に指定され，分布拡大防止・防除が図られている。セイタカアワダチソウやナルトサワギクなどのキク科の植物種は，道路のり面や路傍の空地などに侵入しやすい一方，森林内には侵入しにくい傾向にある。本報告では，土壌環境と植物の生育に着目し，ナルトサワギクに対し，改良客土(酸性・低栄養塩類型植生基材)を用いた成長抑制実験を行った結果を報告するものである。

The shrinkage of Aral Sea has teld to the decline of wetland ecosystems in lower Syrdarya region. One of the rehabilitation approaches was conducted by the dam construction between Small and Great Aral Sea in 2005. We aimed to evaluate the fluctuation of the wetlands before and after the new dam completion. We analyzed satellite images from 1999 to 2006 based on ground truth data and depicted the wetland area and the NDVI. Comparing variables of wetland; area, length of surrounding, averaged NDVI, sum of NDVI and length of adjacent water in each year, it is appeared that all values of each variable are decreased from 1999 to 2004. On the contrary, they are increased in 2006, and averaged NDVI and LAW is increased remarkably. The ecosystem of the wetland been rehabilitated after the durable dam completion, and there is a possibility to recover the biodiversity.

Damage of Mass Japanese oak mortality in Aichi Prefecture by Raffaelea quercivora was confirmed in 2005 at first, and also spreaded in EXPO 2005 Commemorative Park until 2007. In this study, the damage of Mass Japanese oak mortality in this park was investigated and the cost of pharmaceutical expense for prevents their behavior at the entire park was calculated. As a result, the mortality of Quercus serrata was 17.0% in RINSYOKAEN plot and 14.3% in SHINRINRAKUEN plot. Moreover, there are 587 trees which should inject the medicine for Mass Japanese oak mortality in the entire park, and the cost was calculated 6394400 yen as initial cost (3394400 yen for medicine injection, 3000000 yen for management of dead trees). The expansion can be prevented by executing a prior medicine injection to Q. serrata Murray subsp. mongolicoides H.Ohba. that encounters the mass attack easily and preservation value is high in this region.

This research aimed to verify the influence which roots cutting exerted on the growth of the roadside trees, and to management of an excellent street landscape through the comparison with the tree form. 40 trees (cornus florida L.) were divided into roots cutting group and control group (each 20 trees), and trees height, amount of branch extension, diameter of trunks, number of leaves, and maximum photosynthetic rate (Pmax) were measured at existed 18 trees from June to September, 2008. As a result, the average of trees height on roots cutting was 0.41cm lower than control, the average of diameter of trunks on roots cutting was 0.03cm higher than control. The diameter of trunks has grown instead of the tree height's decreasing. By the coloring water absorption experiment, the root on the cut side supplied water to the same side branch, then the number of leafs in the branch on cutting side has decreased by water absorption trouble. But, Pmax was maintained from the rise of the amount of water which was able to be used at the individual leaf. It was suggested that natural tree form of roadside trees were able to be maintained by roots cutting.

We investigated height errors of wooden poles and plant tops at different measurement ranges using a terrestrial laser scanning system. Then tree heights calculated from the laser scanner data were compared with those derived from manual field measures in an open forest. Therefore heights of wooden poles and plant tops were overestimated at the finest angle stepwidth, but underestimated at available angle stepwidth for almost all measurement ranges. Accuracy of tree heights derived from the laser scanner data by manual operation was high and the mean error of those was -0.02m in this forest. But tree heights calculated from the point clouds buffered around locations of tree bases were often overestimated because the points corresponded to neighbor trees were misrecognized as those corresponded to own tree.

We investigated the distribution of A. squarrosum in the semi-fixed and shifting sand dunes at Mu Us Desert in Inner Mongolia. The relative elevations from the groundwater level to the A. squarrosum community, as well as the form and biomass of A. squarrosum were investigated. Research shows that A. squarrosum plants grew at elevations between 108 cm and 532 cm above the groundwater level. In plots over 500 cm above groundwater level, A. squarrosum is the most dominant species. In addition, the community of A. squarrosum was found in the environment in which other species didn't grow easily, such as areas where water supply to plants is limited. The long main root of A. squarrosum enables the plant to access dewfall water or moisture from under dry sand. The form T/R ratio of A. squarrosum was under 1.00 because of the main root length, and the biomass T/R ratio was over 1.00. The biomass of A. squarrosum was determined using the approximation method.

This research investigates a process from the origin to the decline of the Plant Clinic business that was affiliated to “The Nippon Plant Protection Society (1913-1943)” which carried out the Plant Clinic business in the city from scientific aspect at the Taisho period, and referred to the outlook and challenges of future tree treatments. As a result, the Plant Clinic business was established for “The plants' protection” by advanced knowledge of clinic's members, and the factor of decline was an estrangement between the purpose of the clinic and a social request. Through the process from the origin to the decline, the relation between the science introduced into the business and the social request was cleared. Therefore it was considered that the outlook and challenges of future tree treatments is necessary to introduce scientific verification and technology.

Classification tree model was developed using distribution data of T. dentata and current climate dataset. The suitable habitats (SH) in Japan under current and climatic change scenario (RCM20) were predicted using the model. The model, deviance weighted score and predicted SH revealed that the influential climate variables for the distribution were WI(warmth index) and PRS(summer precipitation) mainly, and PRW(winter precipitation) and TMC(minimum temperature for the coldest month) locally The number of second mesh cells of SH under current, 2031-2050 and 2081-2100 of RCM20 scenario was 1,388, 2,179 and 2,813 respectively. The suitable habitats were predicted to shift whole Honshu except high mountain region and Hokkaido, and to reach northernmost of Honshu.

We investigated the relationship between groundwater level and distribution of Cynanchum komarovii in Musu sandy land. As a result, relative elevation at which C. komarovii was distributed ranged from 68 cm to 314 cm at this study area. The dry weight of C. komarovii was highest at the lower part of sand dune, where the relative elevation from groundwater level was 140 cm. The number of species was lower at the bottom of the sand dune than at other level. According to the groundwater level and the distribution depth of stem and root, it was thought that C. komarovii adjusted by extending the stem to sedimental sand, and grew while using underground water. We consider it could be suitable for use as a ground cover at sites affected by overgrazing in semi-arid land.

This study evaluated the effect of the reduction in atmospheric CO₂ by a planting model of detached houses. The CO₂ reduction effect was evaluated by the amount of CO₂ fixed by planting trees and by the shading effect of planting trees reduced air conditioning energy. The CO₂ reduction planting model was calculated at a maximum rate of 70.16kg-CO₂/year in reduced atmospheric carbon. The amount of CO₂ reduction by shading effect of planting trees was larger than fixing effect. These result showed that necessities to investigate the planting design for the shading effect, as measures of the global warming in the future.

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.

This study sent out a questionnaire about CO₂ reduction by planting of trees to residents of detached houses. The results of questionnaire indicated that when information was included about "CO₂ reduction by planting trees",there was a significant difference in the number of respondents who selected the plan for CO₂ reduction, compared to those who did not receive the information. In addition, providing information about CO₂ reduction resulted in increased awareness of people concerning greenery and the environment. Therefore it was suggested that providing information on this topic will promote the use of greenery around detached houses as a countermeasure to global warming.

There are a large number of examples poor of growth of trees in Kabokurinen of Yumebutai (34 33' 30. 4N, 135 0' 30. 7E) north AWAJI-island in Hyogo. (Original planting was in 1998) It is necessary to investigate the cause of poor growth and to relate to future management plan. Therefore, the weather stations were set to establish the environment of the planting sites. Tree growth factors (height, canopy spread and girth) and soil (moisture, temperature and electric conductivity) were measured. Soil amending work was also carried out to recover the vigor of Cornus florida, over 2 months period, photosynthetic rates were measured to assess effect of soil amending work. Results show that, a large improvement was suitable for a poor water area. The other way around a small improvement was suitable for a rich water area. It is important for management to consider these factors.

Recently, desertification progresses at Mu Us Desert in Inner Mongolia, vegetation is damaged by the over-use of nomads. This changed fixed dunes to semi-fixed and flux dunes. We investigated the distribution of A. squarrosum in the semi-fixed and flux dunes. The relative elevations from the ground-water level to A. squarrosum colony were researched. Moreover, the photosynthetic abilities of leaves growing at three layers (height 15cm, 30cm and 45cm) were measured. <BR>As a result, A. squarrosum appeared between 107cm and 509cm in the relative elevation from the ground-water level. In addition, A. squarrosum was only present in a quadrat away from 327cm or more in the relative elevation from the ground-water level. Pmax in each individual leaf measured at the height of 15cm from the ground was 6.20&mu;molm^-2s^-1, at 30cm was 5.59&mu;molm^-2s^-1 and at 45cm was 2.18&mu;molm^-2s^-1. The Pmax at the upper leaf(45cm) is less than that of the lower leaf(15cm, 30cm).

In this paper, we clarified physiology revitalization of Eucalyptus introduced into Japan and species composition of fructification. The appearance research of the fruit body was done in the Kameyama-city, Mie Pref. and Minami-awaji-city, Hyogo Pref. The relation to the eucalyptus and the physiology revitalization of an ectomycorrhizal fruit body was clarified. As a result, 12 kinds of fungal species were found, 4 kinds of ectomycorrhizal fruit bodys were found in the Kameyama-city, 2 kinds were found in the Minami-awaji-city. An ectomycorrhizal fruit bodys were generated for May until December except August and November. It was suggested that number of fruit bodies have increased by the rise of the SPAD value or the temperature, to settle due to the decrease in the temperature.

Necessary environmental conditions for healthy tree growth in artificial peninsula have been proposed. Lithocarpus edulis, Quercus phillyraeoides were selected for this study. They were planted at regular intervals on the line which intersects at right angle to waters edge. Environmental factors [average temperature, max temperature, minimum temperature average, average wind velocity, max wind velocity, rainfall, daylight hours, WI, CI, soil exchangeable Na accumulation] and plant growth characteristics [height, tree width, diameter, and maximum photosynthetic rate (Pmax)]were measured.Results show that, the Pmax has decreased with rising of the soil exchangeable Na accumulation.It was recognized that Lithocarpus edulis phillyraeoides does not grow healthy if it is within 48m from seaside, or if 50.6mg/100g of soil exchangeable Na accumulation or more. It was also recognized that Quercus phillyraeoides does not grow healthy if it is within 88m from seaside, or if 25.0mg/100g of soil exchangeable Na accumulation or more.

As to the growth characteristic of Senecio Madagascariensis (fireweed) it is spread to become a problem was clarified, and the dissemination of information about the problem was examined. Fireweed's germination ability does not decrease if the seed is saved for one year. In an experiment, fireweed was sown under pasture grasses that grow well on Awaji Island; the seed germinated but did not mature. The threshold of leaf length in grasses is more than 190.8mm in Lolium multiflorum and 295.4mm in Avena sativa. It is recognized that fireweed does not grow if it receives total integrated solar radiation of 8.5MJ/m² and 7.6MJ/m² or less. This indicates that the best method of pasture management to prevent fireweed invasion is covering the soil surface with grasses. Fireweed was designated a second groups level invasive species on 1 February 2006. Therefore it is need that the transmission of information and make up information collecting system.

The questionnaire was carried out to the residents who are performing flower cultivation in beds of roadside tree in northern kyoto-city, and they were asked about aim of growing plants, evaluation of cultivation, the frequency and kinds of growing management. Consequently, it was shown by the store located in that plants cultivation in the street space in a residential area is positive, or a neighboring business district that the private management person of a store is enjoying plants cultivation. The residents who grow plants in street space announced the plant to a passerby or neighboring residents, and expecting the exchange with people who led plant cultivation was also shown. Furthermore, the questionnaire to a passerby showed that the plant which neighboring residents grew was bearing a wing, which forms the green of a town, and the necessity for the plant cultivation support by administration was suggested.

This study evaluated the growth of two kinds of trees(Buxus microphylla Sieb. et Zucc. and Juniperus chinensis L. var. procumbens Endl.) in four cold experiment areas and two kinds of trees(Rhaphiolepis umbellata Makino and Pittosporum tobira Aiton) in six warm experiment areas produced from same maternal tree in the same place, were planted in model retainning wall which a soil improvement condition is different. As a result, It became clear that growth of each kinds of trees were correlated with the weather factor of warmth index and highest temperature, were restrained due to snowfall and the fluctuation in the soil water by influence of solar radiation.Moreover, soil improvement increased the correlations and was showing good growth in the same experiment area.

Four kinds of trees (Abelia grandiflora, Rhododendron oomurasaki, Hedera canariensis, Hedera helix Pittsburgh) produced from same maternal tree in the same place, were planted in a model retainnig wall using the same pot and soil. The retainnig wall was set in the direction of north-south of the place at 10 points Nation-wide. Growth data collected monthly together average climatic data was analysed to study the growth condition of the plants on retainnig wall. As a result, Rhododendron oomurasaki and Hedera canariensis withered in Hokkaido. Hedera helix Pittsburgh withered in Hokkaido, Akita and Okinawa. Correlation analysis using factor scores from the significant weather variables determined from factor analysis, showed that it is possible to predict the D²H of trees in different locations. Moreover, the north facing side of the retainnig wall relatively was superior in growth.