Location

 Puding secondary forest flux observation station is located in Longga village, Chengguan town, Puding county, Anshun city, Guizhou province, China. Geographical coordinates: 26°15'N, 105°43'E, at 1158.0m above sea level. It is supported by Institute of Geochemistry, Chinese academy of sciences, and Puding karst ecosystem research station, Chinese academy of sciences (Puding station). This station is one of Chinese ecosystem research network (CERN) stations. There is a flux observation tower inside the station, geographical coordinates: 22°26'03"N, 105°45'08"E. The tower base is at 1166.0m above sea level, the underlying surface of flux tower is mainly humid subtropical returning secondary forest from farmland, which represents the degraded secondary forest ecosystem of Karst Mountain area in the Yunnan-Guizhou plateau.

Climatic

 Puding station belongs to subtropical humid monsoon climate, the average temperature for many years is 15.96℃, total annual rainfall is 1432.85 mm, total annual solar radiation is 413.9 KJ/cm², annual sunshine hour is 1046 h, sunshine percentage is 23.69%, accumulated temperature of lager than 0℃ is 5828.63℃, frost-free period is 340 d.

Vegetation and soil

  The vegetation is mainly subtropical species in the area, such as China fir, pine, Chinese catalpa, Chinese toon, aspen, etc. Under the flux tower, the surface vegetation types are mainly composed of degraded thorn brush, and secondary evergreen-deciduous broad-leaved forest distribute sporadically, average canopy height is about 2 m. The soil type is given priority to calcareous soil, loam in texture and different thickness in different sites.

Observation system

 CERN standard weather station, open path eddy covariance CO₂ flux observation system, 8 channel soil respiration flux observation system, and karst cave CO₂ flux and isotope observation system had been installed in the Puding station. The eddy covariance system was installed and debugged in March 15 2015 and started flux observation since then, it is mainly composed by Gill WindMaster three dimensional ultrasonic anemometer, Li-7500A infrared gas analyzer and Biomet routine weather auxiliary system. The tower is 24m high, ultrasonic anemometer, infrared gas analyzer, radiation, air temperature and humidity sensors were installed at 13.6 m high, soil temperature and humidity sensors were embedded in 10cm, 30cm,50cm deep, the soil heat flux sensors were buried in 10cm deep, flux data sampling frequency is 10 Hz, the average time of flux calculating is half an hour.

Principal Investigator

Weijun Luo

E-mail: luoweijun@vip.gyig.ac.cn