Abstract: We monitored air temperature and air relative humidity and analyzed the microclimate effects and elevational patterns in different forest ecosystems at various elevations in Ailao Mountain and Yulong Snow Mountain. The results showed that the annual dynamics of air temperature inside the forest and in open land at various elevations in two mountains showed an inverted U shape and air temperature of rainy season (May-October) was higher than that of dry season (November-April). In general, open lands had higher air temperature than forests. Forests at all elevations in Ailao Mountain had stronger effects on temperature than that in Yulong Snow Mountain. The absolute difference of air temperature between forest and open land generally increased with elevation. Air temperature inside forest in Ailao Mountain was lower than that in open land at annual scale, while Yulong Snow Mountain showed a same pattern except 3450 m. Thus, Ailao Mountain and Yulong Snow Mountain forests showed cooling regulation effects to a certain extent. Vertical lapse rate of temperature in Ailao Mountain forest (0.52 ℃·100 m^-1) was slightly higher than that in open land (0.50 ℃·100 m^-1), but was lower than that in Yulong Snow Mountain forest (0.55 ℃·100 m^-1) and open land (0.56 ℃·100 m^-1). Annual dynamics of air relative humidity of forest and open land at various elevations in two mountains also showed an inverted U shape. The relative humidity was higher in rainy season than in dry season, and lower in open land than in forest, with a similar pattern of air temperature. Moreover, air relative humidity at higher elevation was higher than that at lower elevation at annual scale. Both Ailao Mountain and Yulong Snow Mountain forests showed cooling and humidifying regulation effects. Ailao Mountain forests had the stronger cooling regulation effect but lower humidifying regulation effect than the Yulong Snow Mountain forests.

Key words: analytic hierarchy process (AHP), comprehensive evaluation index, agricultural drought, spatio-temporal characteristics.