Location

 The desert steppe ecosystem research station (110°19'53.3''E, 41°38'38.3''N, 1409 m a.s.l.) is located about 13.5 km northwest of Bailingmiao town of Damao Banner, Baotou city, Inner Mongolia, China, which belongs to the Institute of Botany, Chinese Academy of Sciences, and Chinese Academy of Meteorological Sciences. The flux tower (110°19'42.2''E, 41°38'38.2''N, 1407 m a.s.l.) is located at a fenced desert steppe region. This station belongs to a temperate degraded Stipa klemenzii desert steppe.

Climatic

 Damao desert steppe ecosystem station belongs to a semi-arid temperate continental climate. The mean annual temperature is 4.6℃, with the monthly mean temperature varying from -14.1℃ in January to 21.4℃ in July, mean annual relative humidity of 47%, mean annual precipitation of 255.2 mm. more than 3100 h of sunshine annually and a frost-free period of about 120 days (Liu et al., 2012; Hou et al., 2013; Yu et al., 2014).

Vegetation and soil

 The vegetation type belongs to temperate short bunchygrass and dwarf semi-shrub desert steppe, plant species include Stipa klemenzii, Neopallasia pectinata, Artemisia capillaries, Cleistogenes squarrosa, Cleistogenes songorica, Astragalus galactites, Hederopappus altaicus, Erodicm stephanianum, Convolvulus arvensis, Convolvulus ammannii, Iris tenuifolia, Caragana stenophylla, Tribulus terrestris, Allium tenuissinum, Aneurolepidium chinense, Asparagus dauricus, Artemisia frigida, Lappula myosotis, Potentilla bifurca, Potentilla multifida, Potentilla multicaulis and Seorzonera divaricata. The underlying surface of flux tower belongs to a degraded Stipa klemenzii desert steppe. The dominant soil type is chestnut soil, and a calcium laminated layer lies at 20–50 cm depth. Total K, total P and soil organic C content are 23.29 g·kg^–1, 0.31 g·kg^–1 and 12.67 g·kg^–1, respectively, with mean bulk density of 1.23 g cm^–3 and pH of 7.4 (Hou et al., 2013).

Observation system

 The open-path eddy covariance instruments mainly include a 3-D sonic anemometer (CSAT3, Campbell Scientific Inc., Logan, UT, USA)(2.3m), a quick-response infra-red CO₂ /H₂O gas analyzer (LI-7500, LI-COR Inc., Lincoln, NE, USA)(2.3m) and a data logger (CR5000, Campbell Scnietific Inc., Logan, UT, USA). These signals were received at 10 Hz, and the raw data were stored in a data logger, while mean scalar fluxes were computed online every 30 min and recorded by the data logger.

Micrometeorological system includes: two temperature and humidity probes ((2.0 m and 3.5 m; HMP45C, Vaisala, Helsinki, Finland), two levels of wind speed monitored using cup anemometers (2.0 and 3.5 m; 014A/034B, Campbell Scientific Inc., Logan, UT, USA), a four-component net radiometer (2.5 m; CNR1, Kipp and Zonen. Corp., Delft, Netherlands) at the height of 3.5 m, a quantum sensor (4 m; LI190SB, LI-COR, Lincoln, USA) at the height of 4.0 m, soil thermistors (107L, Campbell Scientific Inc., Logan, UT, USA) at depths of 5, 10, 15, 20, 40, and 80 cm, soil water time domain reflectometry probes at the depth of 5cm (CS616, Campbell Scientific, Edmonton, Canada), and soil heat fluxes (G) at the depth of 8 cm using two soil heat plates (sHFP01, Hukeflux Inc., Netherland). Total event precipitation was measured using a tipping bucket rain gauge (1.2m; 52203, RM Young Inc., Traverse City, MI, USA). Soil water content was measured at depths of 10, 20, 30, and 40 cm using EasyAG sensors (Campbell Scientific Inc., Logan, UT, USA). Signals from all sensors were recorded by a data logger (CR23X, Campbell Scientific Inc., USA) every 2 s, and 30-min mean/sum data were also logged.

The eddy covariance and micrometeorological measurements have been working at Damao Banner from April 28, 2011.

Principal Investigator

Guangsheng Zhou

E-mail: gszhou@ibcas.ac.cn