Location

Haibei Alpine Meadow Ecosystem Research Station (Haibei Station), a facility run by the Northwest Institute of Plateau Biology,Chinese Academy of Sciences, is located in the northeastern part of the Tibetan Plateau, China (37o36'44.24" N, 101o18'44.94" E, 3205 m a.s.l.). Our eddy covariance flux tower (37o36'35.67" N，101o19'20.53" E，3202 m a.s.l.) was established on an alpine marsh peatland (Luanhaizi) that located near the Haibei Station.

Climatic

The Haibei Research Station has a continental monsoon climate, with a short growing season and a long non-growing season. Generally, the growing season starts in mid-April and ends in late October. The annual mean air temperature is -1.1 °C with maximum air temperature of 17.3 °C and minimum air temperature of -33.6 °C. The mean annual precipitation is 490 mm, of which about 90% occurs during the growing season. The annual average sunlight is 2463 hrs.

Vegetation and soil

The plant community of Haibei Station is dominated by Kobresia humilis, Festuca ovina, Elymus nutans, Poa pratensis, Carexsca brirostris, Scripus distigmaticus, Gentiana straminea, Gentiana farreri, Leontop odiumnanum, Blvsmus sinocompressus, Potentilla nivea, and Dasiphora fruticosa. The vegetation of the alpine marsh peatland is dominated by Carex pamirensis, with several other species including Carex alrofusca, Hippuris vulgaris, and Triglochin palustre. The dominant soil type is Organic Cryic Gleysols. The average C and N contents in the 20-100 cm soil layer is 12.2% and 0.98%, respectively. .

Observation system

The measurements of CO2, CH4 and H2O fluxes were started in 23 July 2011 using the open-path eddy covariance method at a height of 2.5 m. The observation system consists of a three-dimensional sonic anemometer (Gill R3, Gill Instruments Ltd., Hampshire, England), a Li-Cor 7500 open path infrared gas analyzer (Li-Cor, Lincoln, NE, USA) for measuring the CO2 concentration and a Li-Cor 7700 open path infrared gas analyzer (Li-Cor, Lincoln, NE, USA) for measuring the CH4 concentration. The instantaneous values of the three components of wind velocity and of CO2, CH4, H2O, and temperature were sampled at 10 Hz with a datalogger. All the covariances were computed over a 30-min period.

Net radiation was measured with a four-component radiometer (CNR-1, Kipp and Zonen, Delft, Netherlands). Photosynthetic photon flux density (PPFD) was measured with a quantum sensor (LI-190SB, Li-Cor, Lincoln, NE, USA). Air temperature and relative humidity were measured using HMP45C temperature and relative humidity probes (Campbell Scientific Inc., Logan, USA) with radiation shields. Soil temperature was measured at a depth of 5 cm using a temperature probe (107, Campbell Scientific Inc., Logan, USA). Soil water content reflectometer (CS616, Campbell Scientific Inc., Logan, USA) was installed 10 cm below the soil surface to measure the volumetric soil water content.

Principal Investigator

Jinsheng He

E-mail: jshe@pku.edu.cn