In recent years, relationship between the forest decline and atmospheric pollution including as acid rain and acid fog has been frequently reported. The major air pollutants are NO2, SO2, and O3, and thus the measurement of these gases within forest areas is very essential to determine the effect of air pollution to forest. In this study, the spatial concentration distribution of atmospheric pollutants such as NO2, SO2, and O3 was investigated on the southern (polluted area) and northern (unpolluted area) slopes of the Mt. Gokurakuji, Hiroshima Prefecture, western Japan. Each concentration level of these pollutants was measured using the molecular diffusion samplers with a vertical interval of 50 m or 100 m. Highest concentration of NO2 was detected at an altitude of 100-200 m on the southern slope, and the concentration decreased as the altitude increased. However, the NO2 concentration was constantly low on the northern slopes. Furthermore, it was estimated that the NO2 concentration was closely related to the land and sea breezes. A measurable concentration of SO2 was detected at a low altitude on the southern slope. Highest concentration of O3 was detected at the summit of the mountain, and the concentration was lowest at the low altitude. Apart from air pollutant measurement, we also investigated the vital degree of several tree species. The mortality of Pinus densiflora, the percentage of expanded leaves and the mortality of Prunus spp. and the percentage of unshed leaves of Eurya japonica were measured at the same sites where the measurement of air pollutants was conducted. It was found that the mortality of Pinus densiflora were high, but the percentage of unshed leaves of Eurya japonica were low in the lower altitude area on the southern slope, and the decline of pine forests advanced much due to the multiple pollution of NO2 and SO2. The percentage of expanded leaves and the mortality of Prunus spp. was not closely related with NO2 concentration, however, the mortality showed a clear difference between the southern and northern slopes.

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To estimate the acid buffer capacity and neutralization characteristics of forest floor, batch and submersion studies were conducted with Quercus serrata and Cryptomeria japonica. Cation exchange capacity (CEC) of each litter was found to be dependent on pH and ionic strength in solution. The CEC of Q. serrata and C. japonica ranged from 22 to 42 and 9 to 17 (meq/100 g dry weight), respectively. Batch studies using acid solution (pH 3.33) indicated that nearly 100 percent of acid added was removed, and that a significant quantity of organic matter was leached out from both litters. The results of the submersion experiment demonstrated that H⁺ neutralization velocity of Q, serrata litter was faster than that of C. japonica litter, and that H⁺ elimination was found to be affected by leached organic matter from the litters. These results suggested that the main acid buffer mechanism on forest floor was not only due to the cation exchange on the surface of litter, but due to the buffer action of organic matter leached from litter.

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Economics development in Asia has caused an increase in the demand for food . Previous studies have shown that there is a relation between income and the demand for food. These studies calculated income based on a variety of government reports . This study proposes a model based on income producing processes . In this model, income is obtained from a calculation involving capital and labor using the CobbDouglas function. These data for income is then used to calculate the demand for food in Japan.

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Although most of the air pollution problems have improved in line with the appropriate regulation policies, the NOx problem has still remained. The main cause of this NOx problem is due to the use of diesel automobiles. Considering the fact that the NOx problem has become so serious, it seems natural to increase the light-oil tax in order to attain the welfare efficiency and equity of the polluters pay principle. This paper presents, therefore, a cohort type of simulation model both, to predict the number of diesel automobiles and the air pollutant volume (not only NOx but also CO, HC, and SPM), and to analyze the impact of the policy to reduce diesel automobiles. By using this cohort model, this study comes out with a model for predicting the number of diesel automobiles and the air pollutant volume under certain policy conditions. According to this simulation, the light-oil price/tax increase policy might be the most appropriate because it has an efficient effect on reduction of the air pollutant volume (not only NOx, but also CO, HC, and SPM) and might be more acceptable to the general public.

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A model was developed for predicting the long term discharge of chemicals applied to golf links. The model consisted of two components. The hydrological component was based on a model with a series of non-linear tanks, and simulated flow through the basin with input of daily precipitation. The chemical component calculated the amount of chemicals discharged as a function of the amount of chemicals applied, the amount retained in the soil, and the discharge from the soil. It was assumed that chemicals that moved into runoff water were discharged into the regulating pondages and was partialy degraded before entering to the stream. Simazine [2-chloro-4, 6-bis(ethylamino)-1, 3, 5-triazine], which is one of the herbicides widely used in Japan was determined. The experimental basin included the golf links (D golf links) and the neighboring upstream forested basin. The daily discharges of Simazine calculated on a daily basis for two years, were consistent with the range of values determined by direct measurements. It was estimated that increasing of the capacity of regulating pondage was effective to reduce the discharge of the herbicide. Results from the simulations using precipitation data for 6 years suggest that the discharge of the herbicide was strongly affected by sequence, amount, and intensity of individual rainfall events and that the annual losses of the herbicide varied from 2.8% to 7.9%.

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Distributions of various bacteria and methanogenic activity on rice roots and plant residue in paddy soil were investigated. Methanogens were usually detected on the rice roots at the population density higher than that in the soil fraction . The density seasonally changed, and in one case it was more than 100 times higher than that in the soil fraction. The densities of sulfate-reducers and anaerobes on the rice roots were usually 10-20 times higher than those in the soil fraction, and that of aerobes was about 3 times higher. The density of methanogens on the plant residue also seasonally changed, and was usually higher than that in the soil fraction. In one case, the density on the plant residue was more than 500 times higher than that in the soil fraction. On the plant residue, the densities of sulfate-reducers and anaerobes were also usually 100-300 times higher than those in the soil fraction, and that of aerobes was usually 30-70 times higher. In all samples, the density of methanogens enumerated on acetate as a substrate was almost always higher than that on H₂-CO₂. In the rice roots and plant residue, as well as in the soil fraction, methanogenic activity was usually detected. The activities per dry weight of these samples showed distinct seasonal changes, respectively. The change in the total bacterial number accompanied with the decomposition of plant residue seemed to be a major factor bringing about the seasonal change in bacterial composition of the microbial ecosystem in paddy field soil .

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