Location

Youyu Loess Plateau Grassland Ecosystem National Research Station is affiliated with Shanxi Agricultural University. The station locates at Weiyuan town, Shuozhou, Youyu County, Shanxi province ( 39°59′29″N，112°19′49″E，asl 1306m ), The vegetation type of the underlying surface of the flux tower is semi-arid grassland, which belongs to the typical grassland of the northern agro-pastoral ecotone.

Climatic

The semi-arid grassland ecosystem in the agro-pastoral ecotone, the annual temperature varies greatly, and the precipitation mainly concentrates in the end of July and the beginning of August, the growing season is from May to September.The annual average temperature was 4.6℃, the annual average precipitation was 425 mm, the lowest monthly average temperature was -14.0 ℃ in January, the highest monthly average temperature was 20.2 ℃ in July, and the frost-free period was 94-146 days. Drought in spring, extreme precipitation in summer.

Vegetation and soil

The dominant species is Leymus leymus, accompanied by Puccinellia distans, Artemisia anethifolia and Potentilla anserina.The canopy height is 0.45m, and the soil is chestnut calcareous soil.The contents of sand, silt and clay in 0-100cm soil were 56.2% , 24.5% and 19.3% respectively. Soil organic carbon, total nitrogen and available phosphorus were 5.43 ± 0.16 g·kg^-1,0.8±0.02 g·kg^-1 and 3.39 ± 0.09 mg·kg^-1, respectively. The soil pH range is 9-10, and the soil salt content is 1.4-3.9 g·kg^-1. It is a heavy saline-alkine grassland.

Observation system

Li7500 CO2/H2O, infrared gas analyser, Li-cor, USA(1.7m height);

Sonic anemometer(1.7m height);

On-line flux calculation module, smartflux3, Li-cor, USA;

The sampling frequency was 10 Hz and the average time of flux was 30 min;

Start observation date: April 5, 2023

Principal Investigator

Changhui Wang

E-mail: changhui.wang@sxau.edu.cn