Climate

Unlike Savannas, steppes and related temperate grasslands occur at mid-latitudes with at least seasonally low temperatures and frost occurrence. They typically occur under semi-arid conditions that render tree growth impossible, or constrained to water surplus sites. Though overall low, precipitation is concentrated in certain seasons, when monthly precipitation totals may be high enough for relatively large herbaceous growth. Under even drier conditions with permanently higher water deficits, steppes are replaced by (cold) deserts. While steppes of western Inner Asia (e.g. Kazakhstan) and western Eurasia / Europe have a high share of winter or spring precipitation, temperate grasslands of China typically have the largest share of precipitation in the summer month. The temperature and precipitation pattern allow us to distinguish two main sub-regions.

• Eastern Eurasian steppe region
  Summer is mainly controlled by the southeasterly maritime monsoonal system in summer, thus being warm and relatively humid, while winter is primarily controlled by the Mongolian high-pressure anticyclone system, thus being cold, dry and windy.

  The mean annual temperature ranges from -3°C to 5°C depending on locality, with the coldest and warmest month means at from -7°C to -29°C (January) and 18°C to 26°C (July), respectively. The annual precipitation varies mostly between 200 to and 500 mm; inter-annual variability is pronounced, and about 70% of rains fall in the plant growing season, beneficial to plant growth. In the growing season, monthly mean precipitation totals may reach up to 80 mm / month.

• Alpine grassland region
  Summer is strongly influenced by South Asian and East Asian monsoons, while winter is controlled by Westerlies and the Sibirian High, typically cold.

  Patterns in mean annual temperatures are more directly controlled by topography; most areas have an annual mean of from -5.8 to 3.7°C, and the means of the coldest and warmest months range from -17 to -8.0°C, and from 5.5 to 13.6°C, respectively. Precipitation decreases from above 400 mm in the southeast to below 100 mm in the northwest.

Citations

Li, B., Wang, J., Lei, M., et al.(1980). Steppes and savannas. In Wu, Z (ed.) Vegetation of China. Beijing: Science Press. (in Chinese)

Wang, J., Zhang, J., Zhou, X., et al. (1980).The Qinghai-Tibet Plateau alpine vegetation region. In Wu, Z. (ed.) Vegetation of China. Beijing: Science Press. (in Chinese)