A laboratory study was carried out to investigate the suppression of wave-induced bottom erosion by a submerged macrophyte zone in lakes and seas. In the experiments, wave height, wave-induced velocity and bottom sediment movement were measured and observed in the presence of a submerged macrophyte zone. The wave height significantly and monotonically decreased through the macrophyte zone, in contrast, the wave-induced velocity profiles complicatedly changed in the macrophyte zone. In addition, bottom sediment movement were greatly suppressed by the macrophyte zone. Finally, it was shown that a submerged macrophyte zone plays important roles in wave motions, wave-induced flows, bottom sediment movement and their interactions.

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 This study examined the suitability of municipalities in Wakayama Prefecture for the construction of a wood biomass power plant. The study considered seven indicators: energy made from available wood biomass, existence of competition for wood chips, distance between Wakayama city and the plant construction site, forest abundance, cost of transporting from the chip plant, cost of wood transporting from forest site, and grid connection cost. The indicators used in the study were able to be categorized as focusing on either "the stable procurement of fuel (cost)" or "the collection of capital investment (delivery)." The positive and negative aspects of each municipality were also tabulated and considered. Tanabe city, Katsuragi town and Hidakagawa town had higher scores in five indicators, suggesting that these city and towns in Wakayama Prefecture would be suitable for the construction of wood biomass power plants.

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 To increase the annual yield of greenhouses, CO₂ enrichment has been increasing in popularity in Japan. For appropriate use of the instrumentation, scientific knowledge of the environmental response of canopy photosynthesis is required. However, a lack of such knowledge by growers and instructors, e.g. agricultural extension workers and farming instructors, has resulted in scientifically inappropriate usage of such instrumentation in commercial greenhouses. To solve this problem, an adequate learning tool for growers and instructors to obtain enough knowledge of the environmental response of canopy photosynthesis is required. In this study, we developed an MS Excel based annual yield estimation tool for greenhouse tomato production. This tool is composed of 10 spreadsheets. Each spreadsheet has a particular function; an equation for leaf area estimation (Sheet 1), a model for vertical leaf area distribution (Sheet 2), a model for vertical light distribution (Sheet 3), a model for photosynthetic light (and CO₂) response of leaves (Sheet 4), a model for dry matter distribution within a plant body (Sheet 5), specifics of greenhouse structure and parameter settings for greenhouse environmental control (Sheet 6), data on solar radiation and air temperature at intervals of 1 hour (Sheet 7), estimation of total photosynthesis of tomato canopy without CO₂ enrichment (Sheet 8), estimation of total photosynthesis of tomato canopy with CO₂ enrichment (Sheet 9), and estimation of expected annual tomato yield (Sheet 10). By using the developed tool, we investigated the effect of CO₂ enrichment in a greenhouse located in Matsuyama City (Ehime Prefecture, Japan) and demonstrated that CO₂ enrichment at 8.0 kg 10 a ^-1 h^-1 increased the annual tomato yield at 38.9% but further CO₂ enrichment above 10 kg 10 a ^-1 h^-1 was not effective to improve annual tomato yield.

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