Location
Forest Grass Transition Zone Grassland Ecosystem Positioning Observation and Research Station of Xing'an League in inner Mongolia is affiliated with School of Grassland and Grassland, Beijing Forestry University( 46°41′19″N，120°30′23″E，asl 746m ), the vegetation type of the underlying surface of the flux tower is temperate meadow grassland, which belongs to forest grass transition zone in Xing'an League, Inner Mongolia.
Climatic
The study area is located in the transition zone between the the Inner Mongolian Plateau and the Songliao Plain, and belongs to the semi-arid continental monsoon climate in the middle temperate zone. Due to the main ridge line of the Great Xing'an Mountains in the west and the Songliao Plain in the east, the surface vegetation ranges from secondary forests to grasslands, making it a transitional zone between forestry and agriculture. The four seasons are distinct, with a cold and dry climate, a long and cold winter, dry and windy spring, warm and short summer, concentrated precipitation, and hot rain in the same season. The frost-free period is relatively short, with sufficient sunlight, less precipitation, and large evaporation. The annual average wind speed is 2.8m/s, with the maximum wind direction being the west wind, with a wind direction frequency of 23.2%. The annual frost-free period is 99 to 188 days. The annual average precipitation is 449.0mm, mainly concentrated in June to August, accounting for 61% to 89% of the annual precipitation. The annual average temperature is 2.9 ℃ and the annual evaporation is 1648.0mm. The annual average sunshine duration is 2790.7h.
Characteristics of climate anomalies that are prone to occur: floods, droughts, hail, snow disasters, etc. Flood disasters occur once a year, mainly from July to September; Hail occurs four times a year on average, mainly from June to August in summer.
Vegetation and soil
The flora belongs to the Eurasian coniferous forest flora, with trees mainly including Larix gmelinii (Ruprecht) Kuzeneva, Quercus mongolica Fisch. ex Ledeb., Betula dahurica Pall., Betula platyphylla Suk. Populus davidiana Dode, etc. The shrubs mainly including Rhododendron simsii Planch., Lespedeza bicolor Turcz., Spiraea salicifolia L. Prunus sibirica L. Corylus heterophylla Fisch. ex Trautv., Malus baccata (L.) Borkh., etc. The grassland type is a temperate meadow grassland, and the established species include Stipa baicalensis Roshev., Leymus chinensis (Trin.) Tzvel., Elymus dahuricus Turcz. Filifolium sibiricum (L.) Kitam., Thymus mongolicus Ronn., Lespedeza bicolor Turcz., Bromus inermis Layss., Cleistogenes serotina (L.) Keng, Carex duriuscula C. A. Mey., etc.
Observation system
Equipment composition of the flux observation system: CSAT3 ultrasonic anemometer+EC150 infrared gas analyzer (Campbell, USA).
Installation height of observation equipment: flux tower height: 15m; Installation height of flux observation system: 15m; Installation height of air temperature and humidity meter: 15m, 5m, 1.5m; The solar radiation height is 1.5 meters; The installation height of the rain sensor is 1.5 meters; Installation depth of soil temperature and humidity sensor: 5cm, 10cm, and 20cm underground.
Observation frequency: The data sampling frequency is 10Hz, and the average flux time is 30min
Principal Investigator
Qiang Yu
E-mail: yuq@bjfu.edu.cn