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Abstract: This paper describes the first results from a hydro-micrometeorological study designed to characterize the surface exchanges of water, and CO2, at a sky island forest site in the Santa Catalina Mountains. Data collected between June 2002 and December 2004 is used to describe the seasonal water/carbon dynamics of this ecosystem. During the severely dry pre-monsoon period (May–June) when vapor pressure deficit exceeded 2kPa, daytime relative humidity was below 20%, and soil moisture was less than 10%, the predominantly Douglas Fir/Pine forest severely reduced or curtailed its photosynthetic activity. At the onset of the monsoon season in July, the vegetation responded rapidly to the precipitation input, as soil moisture increased. The trees then remained relatively active throughout the fall and winter, particularly if there was adequate winter precipitation which promoted very high productivity into early spring. Given the relative importance of mountain island forest in this semi-arid landscape in terms of its contribution to area-average surface water and carbon exchange, the strong and somewhat unusual coupled seasonal cycles, this forest ecosystem likely has hitherto unrecognized implication for the seasonality of the regional-scale water and carbon cycle. [Copyright &y& Elsevier]

A new method was investigated for the improvement of salt-affected soils in regions where a sufficient amount of rainfall occurs in summer and the heat transfer coefficient and thermal conductivity of their soils were discussed. The subsoil is made coarse by soil sintering, and the capillarity from groundwater is cut-off. Thus, the rise to the soil surface of salts which are dissolved in the groundwater is prevented, and even if the groundwater level is high, the evaporation of water from the soil surface is reduced. In this paper, the heat transfer coefficient and thermal conductivity of the salt-affected soils were determined at the sintering temperatures (850–950°C) in order to obtain basic data for soil sintering. Based on these values, design and construction of a device for soil sintering will be described in a subsequent report. The results show that the heat transfer coefficient to the steel surface was about 40Wm−2K−1 in the range of 280–320°C. The heat transfer coefficient of the studied soil surfaces was about 60Wm−2K−1 in the range of 700–1000°C regardless of types of soil. The thermal conductivity of pseudogley soil from Japan was about 0·1Wm−1K−1 (specimen temperature was about 900°C, and soil water content was 0% dry basis) when the solid ratio was less than 0·38, and it was about 0·3Wm−1K−1 when the solid ratio was more than 0·38. The thermal conductivity of solonchak and solonetz from China was 0·1–0·3Wm−1K−1 (specimen temperature was about 900°C, and soil water content was 0% dry basis) regardless of the types of soil and horizon. The thermal conductivity of the upper layer soils of the solonchak and solonetz did not increase with greater solid ratio because salts contained in them make for a low thermal conductivity. [Copyright &y& Elsevier]