[Microclimate characters of urban forest in Shenyang]

This paper analyzed the diurnal changes of the temperature and humidity in Shenyang urban forest during its different growth stages. The results showed that air temperature was the lowest in the morning and the highest at noon. The highest peak point of air temperature lagged behind that of solar radiation about 2 hours, due to the influence of forest environment. The annual air temperature amplitude was in order of stop-growth period (dormancy stage) (DS) > prophase of growth season (PGS) > anaphase of growth season (AGS) > medium-term of growth season (MGS). Soil temperature of PGS, MGS and AGS at daytime was higher than that at night, while that of DS was in reverse. The daily soil temperature amplitude at different growth stages was in order of upper soil layer (20 cm) >medium soil layer (40 cm) >lower soil layer(80 cm),while the diurnal soil temperature amplitude in the same soil layer was in order of PGS > AGS > DS > MGS (20 cm) and PGS > DS > AGS > MGS (80 cm). The diurnal change of relative humidity was reverse to that of air- and soil temperature, which was higher at night than at daytime, and was in order of MGS > AGS > DS > PGS.