Research on Microclimate Characteristics of Forests in Winter and Spring at Forest Ecological Station in Central Yunnan Plateau

The Quercus acutissima + Q. variabilis mixed stands and Pinus yunnanensis forests at Kunming arboretum of forest ecological station in Central Yunnan plateau was taken as the research object, adopts the positioning observation to reunite and forest microclimate experimental methods, 5 meteorological factors including air temperature, air humidity, light intensity, soil temperature and wind speed, were analyzed to explore the microclimate characteristics of typical forests in the region. The results showed that the effects of Q. acutissima + Q. variabilis mixed stand and P. yunnanensis forest on meteorological factors were significant. The light intensity, soil temperature and wind speed inside the forest were significantly lower than those outside the forest, and the air humidity inside the forest was significantly higher than that outside the forest. The monthly average temperature and minimum temperature in the forest were both higher than that outside the forest, and the maximum temperature in the forest was lower than that outside the forest. The air temperature inside and outside the forest was lower in morning and evening and higher in day. The variation of air humidity is high in morning and evening and low in noon. The diurnal variation of solar radiation intensity showed an inverted U-shaped curve. With the increase of soil depth, the difference decreases gradually. The variation of wind speed is low in morning and evening and high in day. The correlation between air temperature and air humidity is the highest in both Q. acutissima + Q. variabilis mixed stands and P. yunnanensis forests.