Location
Zhejiang Tiantong Forest Ecosystem National Observation and Research Station is affiliated with East China Normal University. The station locates at Tiantong National Forest Park, Ningbo City, Zhejiang Province, China ( 29°48′45″N，121°47′11″E，asl 295m ). The vegetation type of the underlying surface of the flux tower is Subtropical evergreen broad-leaved forest.
Climatic
Typical subtropical monsoon climate, with hot and humid summer, cold and rainless winter.
The mean annual temperature is 16.2 ℃, ranging from 4.2 ℃ in January to 28.1 ℃ in July. The mean annual precipitation is 1551 mm, with main precipitation months from May to August, and the mean annual evaporation is about 1320 mm. The annual relative air humidity can reach up to 85%. The annual sunshine duration is about 2010 h, and the frost-free period reaches 237.8 days.
Vegetation and soil
This region belongs to the evergreen broad-leaved forest ecoregion of the Zhejiang-Fujian Mountains in eastern subtropical China, with various types of vegetation, obvious succession stages, and rich flora. There are 968 species of seed plants, 96 species of ferns with 9 varieties, and 170 species of bryophytes. The dominant species are Castanopsis fargesii, Schima superba, Castanopsis carlesii, and Cyclobalanopsis sessilifolia.
The flux tower was built in October 2020. The canopy height is 10-15m and the dominant canopy tree species around the flux tower are Castanopsis fargesii, Schima superba, and Castanopsis carlesii. The dominant understory shrubs are Eurya loquaiana and Camellia fraternal. The dominant understory ferns are Diplopterygium glaucum and Woodwardia japonica.
The soil type is Acrisol.The mean depth of soil layer is about 1 m, with its texture being a clay loam with 6.8% sand, 55.5% silt, and 37.7% clay. The soil pH is 4.4-5.1, and the contents of soil organic carbon, total nitrogen and total phosphorus are 3.8-5.2 mg/g, 0.25-0.36 mg/g and 0.12-0.21 mg/g, respectively.
Observation system
The flux tower is 50m tall and includes an open-path eddy covariance system and a conventional micrometeorological observation system. The open-path eddy covariance system mainly consists of an open-path infrared CO2/H2O analyzer (Li-7500, LICOR) installed at 40m and a 3D ultrasonic anemometer (CSAT-3, CSI), with a frequency of 10Hz. Real-time data collection automatically calculates the flux data and takes a 30-minute average value. The conventional meteorological observation system (including products such as HMP45C) includes two layers of total radiation, net radiation, and point photosynthetically active radiation installed at 40m and 30m respectively; air temperature and humidity sensors (HMP45C, CSI) are installed at 40m and 10m heights to measure air temperature and humidity; a rain gauge for measuring precipitation is installed at 10m; a soil moisture observation instrument is placed below the surface at 5cm, 10cm, and 20cm depths to measure soil moisture content; soil temperature sensors are placed below the surface at 5cm, 10cm, and 20cm depths to measure soil temperature; three soil heat flux plates are installed at 5cm, 10cm, and 20cm depths underground to determine soil heat flux; micrometeorological data is stored in half-hourly average values.
Principal Investigator
Kun Huang
E-mail: khuang@des.ecnu.edu.cn