Table 1 Environmental data of the four field sites
Site | Longitude (° E) | Latitude (° N) | Altitude (m) | Mean annual precipitation (mm) | Annual mean temperature (°C) | Sunshine duration (h/year) | Aridity index (I dm) | Moisture types | Vegetation classification | Soil type |
|---|---|---|---|---|---|---|---|---|---|---|
Xilinhaote | 115° 55′ 19″ | 44° 28′ 31″ | 990 | 281 | 2.35 | 2932 | 22.75 | Semi-arid | Steppe | Dark chestnut soil |
Siziwang | 111° 53′ 22″ | 41° 47′ 28″ | 1492 | 240 | 3.40 | 3065 | 17.91 | Arid | Desertification steppe | Light chestnut soil |
Etuoke | 107° 58′ 02″ | 39° 07′ 02″ | 1500 | 210 | 6.40 | 3050 | 12.80 | Very arid | Semi-desert | Brown soil |
Alashanzuo | 105° 41′ 34″ | 38° 19′ 47″ | 1561 | 110 | 7.80 | 3200 | 6.18 | Intensively arid | Desert | Gray desert soil |