This study aims to clarify the stand structure on the embankment slope which has been 11 years since the initial planting of certified native species seedlings. On the survey plots (total 300 m²), a total of 29 vascular plant species, where 14 species of tree plants, were confirmed. From plotting the tree height distribution, a double layer structure was confirmed, in which the upper layer was dominated by P.densiflora, and the lower by Q.serrata. It was suggested P.densiflora suppress the growth of other plants in the lower layer; on the other hand, improvement of light environment was predicted with decline of P.densiflora..

In this study, in order to identify how differences in soil properties affect the reinforcement effect of root systems of herbaceous plants, we conducted constant pressure direct shear tests at low vertical stress using specimens produced by seeding in volcanic sandy soil and volcanic cohesive soil and developing the plant root system. The results indicate that development of the root system improves soil toughness regardless of differences in soil properties. They also indicate that the freeze-thaw history affects the shear strength of soil specimens containing the root systems of herbaceous plants differently depending on the soil properties.

In order to clarify the changes in elemental concentrations and decomposition characteristics of plant organic matter in urban green areas, we investigated road area ratio, chemical characteristics in soil, elemental concentrations and decomposition rate of plant organic matter of Carpinus tschonoskii among urban green areas and mountainous areas. As a result, nitrogen (N) and manganese (Mn) concentrations of C. tschonoskii were increased in urban area. Consequently, the urban environment enhanced decomposition rates in early stage of decomposition process but inhibited then in latter stage. From the results, it seems that soil organic matter qualities were changed in urban green area.

We evaluated O₃ response of nine Sedum species commonly used for green roofs. Plants were exposed to O₃ with 120 ppb once a week for two months. O₃ responses of dry mass, which were mainly caused by those of photosynthetic nitrogen utilization efficiency, differed among the Sedum species, but the responses were at most ±10%. Plant cover decreased with O₃ exposure, but the decrease was at most about 15%. Our results show that green roofs using Sedum species are likely to be sustainable under urban environment where warning for photochemical smog is issued about once a week.

To understand the establishment process in an artificial urban forest the influence of forest floor environment on the regeneration process of woody seedlings was studied. In broad-leaved stands, Sasa nipponica dominated and in coniferous stands there were no specific dominating species. In both stands the light conditions of the forest floor were low. Even though broad-leaved stands have sufficient light for understory plants, the survival rate of seedlings is low. In coniferous stands the survival rate is high. Factors other than forest floor light conditions in broad-leaved stands dominated by S. nipponica must be considered.

We investigated changes for amounts of 14 elements involved in atmospheric pollution in rooftop turfs over the years. All elements concentrations of grasses in rooftop turfs increased after completion and amounts of all elements except for thallium (Tl) of grasses and organic layer increased with age. These results suggested that the deposite elements in grasses accumulated in organic layer as thach. In addition, amounts of cadmium (Cd), plumbum (Pb), nickel (Ni), copper (Cu), zinc (Zn), and argentum (Ag) per unit area of rooftop turf increased after completion. Therefore, it was shown that rooftop turfs have atmosphere purifying capacity.

The distribution characteristics of an invasive alien species Rudbeckia laciniata was analyzed in Nichinan Town, Tottori Pref. in Chugoku mountain area. A total of 8,431 R. laciniata ramets were confirmed in 9 rivers, and gathered the uppermost stream of the river with human disturbances. We carried out a mowing management of R. laciniata in field and verified its effect on plant communities. R. laciniata is the strong competitor and the surface treatments did not affect the species diversity. It is considered that finding the conditions in which native plants dominate may be the start of suppressing R. laciniata ecologically.

We examined whether a flood control basin can mitigate the decreasing habitat for wetland vegetation. In the Maizuru basin constructed in Chitose-river watershed, the plant species, years from excavation, and environment factors were investigated. We found that 1) wetland vegetation was composed by native plant species, 2) years from excavation, water level, pH, and electrical conductivity of surface water were the factors differentiate the habitat of each plant community. 3) Bog's rare plant species formed wetlands until 1920's, but rich fen's common plant species mainly formed wetlands in 1990's, and the vegetation in Maizuru basin resembled to the one in 1990's.

Lake Biwa Canal is an urban water system representing the Okazaki area which was selected as the "Important cultural landscape" in 2015. We surveyed, flowing of drifting aquatic plants into the Okazaki area and the green coverage of submerged plants at Lake Biwa Canal as important ecosystem. We found 11 species drifting and 8 species growing from 85 plots in this canal. We used nMDS analysis based on green coverage and sediment of bottom surface. Egeria densa was found in "Sosui bunsen" with mud. Potamogeton malaianus was found in "Sosui Shirakawa" with middle gravel. Vallisneria asiatica var. biwaensis appeared in both waterway with fine gravel.

In this study, we investigated two chloroplast genome regions of Lathyrus japonicus Willd. in Hokkaido, thereby considering the possibility of utilization as locally sourced seeds. As a result, four haplotypes were detected throughout all survey sites, the haplotypes in one city and five towns were as follows : (1) In Ishikari city, Shinhidaka town and Urahoro town, all individuals had only haplotype A; (2) In Setana town, the individuals had two haplotypes, A and D at a ratio of 2:1; (3) In Okushiri town, the individuals had three haplotypes, A, D and E at a ratio of 7:4:4; (4) In Oshamambe town, the individuals had two haplotypes, A and C at a ratio of 5:2; (5) In Oume town, the individuals had two haplotypes, A and C at a ratio of 9:1. These results revealed that the main haplotype in Hokkaido was A, which matched the haplotype distributed from Hokuriku to Tohoku regions in the previous reports.

In this study, we examined the ratio of the number of trees withering and disappearing after the tsunami disaster that struck the coastal forest of Iwanuma-city, Miyagi prefecture, and the factors thereof. We found that 1,754 trees, red and black pine trees, cherry trees, and konara oak were growing. However, 876 red and black pine trees had either withered or disappeared; the natural mortality rate of red pines was seen to be slightly higher than that of black pines. Furthermore, the number of trees was decreasing due to logging because of reconstruction projects and typhoons, as well as inundation.

We compared midday leaf water potentials, transpiration rates, leaf osmotic potentials at saturation and xylem hydraulic architectures between mistletoes (Viscum album L. subsp. coloratum Kom.) and their hosts. In V. album, their transpiration rates were higher, and their vessel inner diameters, xylem hydraulic conductivities, leaf osmotic potentials and water potentials at turgor loss point were lower than their hosts. Therefore, their midday water potentials could become lower than that of their hosts.

We demonstrated that freeze-thaw episodes of trunks and branches of trees growing in the field can be detected by measuring xylem diameter variations using the strain-gauge method, by measuring trunk water content using the amplitude domain reflectometry method (ADR) and by measuring sap flow velocity using the heat ratio method (HRM). This study clarifies new parameters to monitor accurately the freeze-thaw episodes of trunks and branches of trees growing in the boreal forest.

Availabilities of a large root-ball of Michelia figo was investigated with the changes in sap flow and transpiration rate. The heat pulse velocity decreased 21% of previous value with root cutting. However, there were no large differences in the annual maximum value of the velocity for two years. Three years after transplantation, a large root-ball was made for the same tree, and transpiration rate was almost equal to that of the first large root-ball. Furthermore, after downsizing the root-ball, the transpiration rate and showed 45% of decrease. These results suggest that a large root-ball is expected to promote growth.

Leaves of Japanese beech (Fagus crenata) saplings were clipped at different intensities soon after leaf flushing to investigate the effects of leaf-feeding insect-damage on both xylem hydraulic conductivity of current-year shoots and fine-root mass. The xylem vessel mean inner diameter decreased and the vessel density increased as clipping intensity increased. The specific hydraulic conductivity (Ks) decreased as clipping intensity increased. The ratio of leaves to fine-root mass was strongly negatively correlated, with fine-root mass decreasing as clipping intensity increased.

To investigate the effects of feeding damage caused by the folivorous insects on the xylem of current-year shoots of field grown 10-year-old middle-size Japanese beech trees, we clipped leaves from beech trees at different intensities and seasons. At clipping treatment in May, the xylem vessel mean inner diameter decreased, while vessel density increased as clipping intensity increased. On the other hand, there was no effect at clipping treatment in June. Based on these results, defoliations soon after the leaf flushing by the folivorous insects affect the xylem structure of Japanese beech and these influences extend over the next year.

Viburnum dilatatum seeds have morphophysiological dormancy, and need about 18 months to germinate. In this study, we investigated a method of breaking dormancy by warm stratification, for early sprouting after harvest. Embryo grow and root was emerged from seeds at alternating temperature of 25 ℃ for 16 hours / 15 ℃ for 8 hours (warm stratification) over 90 to 120 days. The generation of cotyledons was stimulated by subjecting the rooted seeds to cold stratification at 0 ℃ under constant temperature conditions for 60 to 90 days. From the above, we succeeded in shortening the number of days required to break dormancy to about 180 days and confirmed that V. dilatatum seeds has deep simple epicotyl dormancy.

Dwarf bamboos often dominate forest floor. Therefore, the information on the ecological properties of dwarf bamboos is necessary for conservation of forest floor in primary forests and management of that in secondary forests. This study examined the effects of topography and canopy species on community structure of Sasa kurilensis dominating the forest understory. The results demonstrated culm diameters in convex are larger than those in concave. Density is higher and dry weight per area is larger under canopy trees of Magnolia obovata and Betula grossa than under canopy trees of Fagus crenata probably because of phenological gaps.

We analyzed forest cover, structure and environment of bark-stripped stands by Japanese black bear (Ursus thibetanus japonicus Schlegel) in Sugi plantations (Cryptomeria japonica (Thunb. ex L.f.) D. Don) of Utsunomiya University Forest and investigated factors affecting bark-stripping. Bark-stripped stands had lager DBH, crown length and volume, and lower clear length ratio, form ratio, species number and vegetation cover percentage of shrub layer. These were located apart from national road and close to ridge top. Multiple regression analysis revealed crown length, relative spacing, slope angle and distance from ridge top were significant independent variables for percentage of bark-stripped trees.

In northern Ethiopia, revegetation is necessary for preventing land degradation. However, planting seedlings show high mortality under arid climate. Biochar has the capacity to enhance seedling survival and symbiosis with arbuscular mycorrhizal fungi. We planted Olea europaea subsp. cuspidata and Dodonaea angustifolia into soil treated with biochar made from Acacia etbaica. We could not confirm the effects of biochar on the growth of these species; however, biochar was increased colonization of arbuscular mycorrhizal fungi. We concluded that application of biochar enhanced symbiosis with arbuscular mycorrhizal fungi under arid climate and was efficient for the revegetation in northern Ethiopia.

Forest cover and strata are important indicators in biodiversity and forest management. However, the ground assessment to obtain these indicators is limited by ocular estimation, which can be subjective. We introduced 3D data from terrestrial laser scanner to quantify forest structure. The 3D data is converted to voxels and different size of voxels is used for this study. The 0.125m of voxel size was the most accu rate within 10 m radius to estimate forest cover. With this resolution, an automatic method to identify forest strata was established from the vertical distribution of the voxels for temperate forest.

This study investigated medical personnel’s consciousness of plants by using an online questionnaire. Results revealed that many medical personnel are aware of the necessity of plants; this includes both the patient’s and personnel’s peace and landscape improvement. “It was further revealed that medical personnel experienced workplace relationships as the most frequent cause of stress. Consequently, being involved with plants may have a positive effect on workplace relationships. Thus, it may be imperative to green hospitals to enhance medical personnel’s mental health.

We conducted profile of mood states (POMS), semantic differential (SD) method and State-Trait Anxiety Inventory (STAI) Y-2 testing of college students after they looked at a greening wall and a concrete wall to examine psychological effects of wall greening. As a result, when students viewed the greening wall both while sitting and walking, their negative feelings were suppressed, and their positive feelings were enhanced. For subjects looking at a green wall while walking, students with low state anxiety in daily contact with plants have a higher feeling of familiarity than students who are not in contact with plants.