Vegetation

Two grassland regions

1. Temperate steppe (Fig. 1): mainly Inner Mongolia Plateau and the northern and western part of the Loess Plateau, typically used as rangelands but up to 10% now converted to crop land. The three main types reflect increasing aridity, typically from southeast to northwest.

  • Meadow steppe
    Distribution range is mainly in the eastern steppe zones and in high desert mountains where annual precipitation is 350-550 mm. It is a transitional type between steppe and forest. Dominant species are mostly mesoxerophilous, xeromesophilous or pan-xerophilous, grasses are abundant but there is a high share of insect-pollinated plants in typical and intact stands of grasses.
    e.g. Stipa baicalensis, S. kirghisorum, Cleistogenes mucronata, Bothriochloa ischaemum and Pennisetum flaccidum; the rhizomatous grasses Leymus chinensis and L. angustus; forbs include several Artemisia spp. the related Filifolium sibiricum but also Veronica, Bupleurum, Potentilla and Dianthus spp.
  • Typical steppe (dry steppe)
    It is found mostly on the Inner Mongolia plateau and at low to midlevel western desert mountains where annual precipitation is 200-350 mm. Grasses built the main matrix, among them many Stipa species; stands in the north-east are relatively tall (tall grass steppes); insect pollinated forbs are present but less diverse than in the meadow steppes.
    e.g. Stipa grandis, S. krylovii, S. bungeana, S. capillata, Festuca valesiaca subsp. sulcata, F. ovina, Cleistogenes squarrosa, Agropyron cristatum, Koeleria cristata, Poa botryoides and Aristida triseta, and semi-shrubs and dwarf semi-shrubs, such as Artemisia frigida and Kochia prostrata, Thymus mongolicus occurs on rocky sites
  • Desert steppe
    It is distributed to the west of the typical steppe and below the mountain steppe, where annual precipitation is 150-250 mm. It is a transitional type between steppe and desert. The species are predominantly strongly xerophilous grasses, usually accompanied by super-xerophilous dwarf semi-shrubs in large numbers.
    e.g. Stipa klemenzii, S. tianschanica var. gobica, S. breviflora, S. caucasica subsp. glareosa, S. orientalis, S. caucasica, Cleistogenes songorica, onion species like Allium polyrrhizum, and the dwarf semi-shrubs Ajania achilloides, Ajania trifida and Artemisia dalai-lamae
Fig. 1 Main grassland types on the Mongolian Plateau. a) desert steppe dominated by Stipa klemenzii; b) typical steppe dominated by Stipa sareptana var. krylovii; c) typical steppe dominated by Stipa grandis; d) meadow steppe dominated by Leymus chinensis and Achnatherum sibiricum; e) meadow steppe dominated by Leymus chinensis with diverse forbs (Iris dichotoma in the front); f) meadows dominated by Sanguisorba officinalis and Bromus inermis; g) Przewalski horses reintroduced on the steppe; h) a pastoral household on the steppe; i) degraded grassland dominated by Artemisia frigida and Potentilla acaulis. The photos a-f were taken along a climate gradient from dry to humid regions; and photos g-i were taken in the typical steppe region.

2. Alpine grassland (Fig. 2): traditionally also called “Tibetan steppe”, occurring mainly on Qinghai-Tibetan Plateau as grazing lands, only 1% is cultivated, e.g. in Qaidam Basin and in the lower valleys of river, such as along the valley and tributaries of the Yarlung Tsangpo (Brahmaputra River). The two main types reflect increasing aridity from the western to the eastern Tibetan plateau.

  • Alpine steppe
    The common and dominant species are cold- as well as drought-tolerant grasses and dwarf shrubs, with a more or less pronounced admixture of cushion plants.
    e.g. Stipa subsessiliflora, S. roborowskyi, Festuca olgae, Carex moorcroftii, Orinus thoroldii, O. kokonorica and Artemisia wellbyi; and common plants of Eurasian steppes such as Festuca kryloviana and F. valesiaca subsp. pseudovina
  • Alpine meadow
    Here the word “alpine” does not strictly refer to high mountain climate too cold to allow for tree growth, but only indicates a high-elevation distribution, not necessarily above the climatic treeline. “Meadows” here refer to natural grasslands primarily composed of mesophilous perennial herbs that thrive under moderate moisture conditions, which are different from the European understanding in terms of agriculturally managed grasslands regularly mown for livestock forage (UNESCO classification). The Kobresia alpine meadows are the most typical and most widespread of the alpine meadows in China. Kobresia species are both mesophilous and cold- and drought-tolerant. There are about 40 Kobresia species, and dominant ones include K. pygmaea, K. humilis, K. capillifolia, K. graminifolia, K. setchwanensis, K. vidua, K. royleana and K. myosuroides. According to recent studies on their systematics, Kobresia should be included into the wider genus Carex.
Fig. 2 a) moist alpine meadows dominated by Kobresia setschwanensis and Polygonum macrophyllum (white flowers) in Maqu, Gansu province; b) winter pastures dominated by K. royleana and K. pygmaea in Yushu, Qinghai province; c) moist alpine meadows in Dangxiong, central Tibet; d) alpine meadows dominated by K. pygmaea in Namco, central Tibet; e) alpine steppe dominated by Stipa purpurea in Qumahe, Qinghai province; f) alpine steppe dominated by Orinus thoroldii in Gaize, western Tibet; g) alpine marshy meadow dominated by K. schoenoides in Linzhou, eastern Tibet; h) large root/shoot ratio from K. pygmaea turf; i) newly built winter settlements from sedentarization project in Qinghai province.
a) moist alpine meadows dominated by Kobresia setschwanensis and Polygonum macrophyllum (white flowers) in Maqu, Gansu province
b) winter pastures dominated by K. royleana and K. pygmaea in Yushu, Qinghai province
c) moist alpine meadows in Dangxiong, central Tibet
d) alpine meadows dominated by K. pygmaea in Namco, central Tibet
e) alpine steppe dominated by Stipa purpurea in Qumahe, Qinghai province
f) alpine steppe dominated by Orinus thoroldii in Gaize, western Tibet
g) alpine marshy meadow dominated by K. schoenoides in Linzhou, eastern Tibet
h) large root/shoot ratio from K. pygmaea turf
i) newly built winter settlements from sedentarization project in Qinghai province.