To clarify the salt stress response of Zoysia matrella from the perspective of salt gland activity, four different concentrations of NaCl solution were used to treat the plants when the pot soil surface appeared to be dry. After 35 days of treatment, the Na⁺ amount in the leaf and excreted Na⁺ increased with increasing NaCl treatment concentrations. The amounts of Na⁺ and Cl⁻ accumulated in the leaves were higher than the amounts excreted. Overall, the adaxial side of the leaves showed a higher salt gland density with larger sizes than those on the abaxial side. No significant differences in salt gland density or size were observed among the four NaCl treatments. Previous studies conducted in a high-moisture environment such as in hydroponic culture showed that Na⁺ excretion was higher than the accumulation in the leaf. In contrast, the present study showed Na⁺ excretion from the leaf was lower than the accumulated amount. These results indicate that salinity in the soil does not affect the leaf salt gland density or size, and salt excretion from Z. matrella may be highly affected by soil moisture rather than by salt gland density or size on the leaf surface. Furthermore, these results suggest that Z. matrella can adjust the amount of salt excretion according to soil moisture.

The purpose of this research is to estimate the improvement effect on the hot environment in summer by railroad track greening with non-irrigation system. The experimental place was around the Arakawa-shakomae station of the Toden Arakawa line, Tokyo Japan. We measured surface and air temperatures on track greening and non-greening areas for comparison analysis from 1 July to 31 August, 2017. In the non-greening area, the surface temperature was recorded at 63ºC as maximum. The track greening area drastically changed the surface temperature to 45ºC, lower than the track non-greening area. We concluded that the time to cool the atmosphere increased by installing track greening with non-irrigation system even at high temperature and low rainfall in summer.