Characteristics of Temperature and Humidity in Forest Ecosystem of Heihe River Basin
Temperature and humidity characteristics of soil and air at different levels are analyzed based on the observed data of typical forest ecosystem of Heihe River basin in 2008.Results show that:(1) Soil temperature at different depths is the lowest between February and March each year and the highest between July and September.Annual temperature difference and minimum soil temperature decreased with the increase in soil depth.(2) The moisture of top soil is greatly affected by snowmelt in spring and rainfall,reaching its maximum value in the middle or last ten days of August.There is less impact of snowmelt in spring on the soil moisture between 20 and 40 cm from soil surface.The soil moisture content between 80 and 120 cm is quite stable and is not influenced by snowmelt in spring.(3) Air temperature at different heights in forest presents a declining trend from the middle of July to the last ten days of January next year and then increases continuously from the early of February to the early of July.Air temperature at 2 m height is a bit warmer than that at 10 and 24 m heights.The highest and lowest daily temperature peaks are observed at about 14:30 and 6:30,respectively.(4) Air humidity in forest is lower between April and June and higher between June and October.The maximum and minimum relative humidity values are observed at about 22:00 and 11:30,respectively.The humidity variation at 10 or 24 m height is similar to that at 2 m height.
Heihe River basinforest ecosystemsoil temperaturesoil moistureair temperaturerelative air humidity