Mongolian Desert and Semi Desert
This formation represents the most extensive natural area of China covering some 1.75 million square kilometres ranging over much of Inner Mongolia and the Sinkiang region and extending into other areas such as Tsinghai. The soils are typically low in organic matter and often saline. In the semi desert areas the vegetation is sparse and limited to draught resistant grasses and shrubs and various halophytes, but is generally typified by a variety of Stipa, Cleistogenes and Allium species. The main shrubs include Artemisia caespitosa, A. incana, Caragana bungei, C. pygmaea, Salsola passerina, Sympegma regelii, Tanacetum achillaeoides, T. fruticulosum, T. trifidum and the endemic Artemisia xerophytica (Asteraceae) and Potaninia mongolica (Rosaceae). In the more extreme desert the vegetation becomes very sparse and patchy. The main species, particularly in saline areas, include Agriophyllum gobicum, Alhagi camelorum, Anabasis brevifolia, Calligonum mongolicum, Caragana leucophylla, Echinopilon divaricatum, Eurotia ceratoides, Kalidium gracile, Nanophyton erinaceum, Peganum nigellastrum, Salsola ruthenica and the endemic Ephedra przewalskii (Ephedraceae) and Nitraria sphaerocarpa (Nitrariaceae). Other characteristic species include the small tree Haloxylon ammodendron together with various species of Reaumuria (e.g. R. soongorica), Salsola passerina, Convolvlus gortschakovii, while the endemics or near endemics include Brachanthemum gobicum (Asteraceae), Potaninia mongolica (Rosaceae) and Zygophyllum xanthoxylon (Zygophyllaceae).
In the most drought-ridden areas Ephedra przewalskii may become dominant in association with other endemics such as Ammopiptanthus mongolicus (Fabaceae) and Gymnocarpos przewalskii (Caryophyllaceae), while in the gypsum deserts Nitraria sphaerocarpa becomes more conspicuous. However, in areas surrounding Lap Nor (the central saline lake) in the Takla Makan Desert the vegetation is made up of just two psammophytes: Agriophyllum arenarum and Corispermum hyssopifolium. On the other hand, the Alashan Desert unlike the Takla Makan or the Ordus deserts is not an unbroken expanse of barren sand. It also includes areas of steppe, gravel desert, marshes and oases, and some of the sand dunes of this desert can reach heights of over 150 m and regarded among the highest in the world. In these more typical desert areas, one of the main psammophytes is the endemic or near endemic Calligonum mongolicum (Polygonaceae). With roots that can penetrate to a depth of 30 m it is well adapted to these arid conditions. Commonly associated species include grasses such as Agriophyllum gobicum, Peganum harmala, Pugionium dolabratum, Timouria villosa and the small tree Haloxylon ammodendron. The latter can reach heights of about 6 m and can form open stands but usually occurs as isolated trees. Ground vegetation usually consists of Convolvulus ammannii, C. tragacanthoides, Inula salsoloides, Kalidium gracile and Nitraria schoberi. In the western part of the Alashan there are extensive gravel deserts. Here a low scrub predominates with species such as Alhagi kirghisorum, Ephedra equisetina, Lycium ruthenicum, Zygophyllum xanthoxylum and the endemic or near endemic Piptanthus mongolicus (Fabaceae). Other endemic species found here include Arnebia szecheny (Boraginaceae), Artemisia xerophytica (Asteraceae), Astragalus dengkouensis (Fabaceae), Brachanthemum pulvinatum (Asteraceae), Calligonum alaschanicum (Polygonaceae), Cancrinia lasiocarpa (Asteraceae), Caragana korshinskii (Fabaceae), Chesneya mongolica (Fabaceae), Cistanche sinensis (Orobanchaceae), Clematis canescens (Ranunculaceae), Corispermum patelliforme (Chenopodiaceae), Cornulaca alaschanica (Chenopodiaceae), Cynanchum cathayense (Apocynaceae), Dontostemon senilis (Brassicaceae), Elachanthemum intricatum (Asteraceae), Euphorbia kozlovii (Euphorbiaceae), Iris bungei (Iridaceae), Kalidium sinicum (Amaranthaceae), Kochia macroptera (Amaranthaceae), Lappula deserticola (Boraginaceae), Lepidium alaschanicum (Brassicaceae), Medicago alaschanica (Fabaceae), Microstigma brachycarpum (Brassicaceae), Myricaria platyphylla (Tamaricaceae), Oxytropis langshanica (Fabaceae), Panzeria alaschanica (family?), Potaninia mongolica (Rosaceae), Prunus mongolica (Rosaceae), Pugonium calcaratum (family?), Reaumuria trigyna (Tamaricaceae), Salsola ikonnikovii (Chenopodiaceae), Saussurea petrovii (Asteraceae), Scorzonera capito (Asteraceae), Spongiocarpella grubovii (Fabaceae), Sterigmostemon matthioloides (Brassicaceae), Stilpnolepis centriflora (Asteraceae), Stipa mongolorum (Poaceae), Suaeda przewalskii (Chenopodiaceae), Tamarix austromongolica (Tamaricaceae), Tetraema mongolica (family?), Tugarinovia mongolica (Asteraceae) and Zygophyllum mucronatum (Zygophyllaceae).
Mongolian Oases
Trees are mainly restricted to oases but most of these are now highly modified. The remaining natural remnants suggest they supported deciduous forest with species such as Acer turkestanicum, Celtis australis, Juglans fallax, Morus alba, Prunus divaricata and various Populus, Salix and Tamarix species including the endemic Tamarix juniperina (Tamaricaceae). On the Joshui River, which flows through the Alashan Desert, there is virtually an unbroken series of oases from Tingshin (Miaomu) to Tsongol. Populus euphratica stands occur along the edges of the river together with Elaeagnus angustifolia, Haloxylon ammondendron and tall thickets of Tamarix including T. juniperina. The tamarix trees are often festooned with clematis giving these forests an almost primeval look. The ground flora often includes many colourful flowers such as Glaux maritima, Gymnocarpus przewalski, Poacynum hendersonii and Sophora alopecuroides, but in the more marshy areas various reeds (Scirpus rufus, S. uniglumis) and rushes (Juncus articulatus, J. bufonius) predominated.
Mongolian Steppe
This extensive formation covering about one million square kilometers extends in a broad band along the edge of the Inner Mongolia Plateau west of the Great Khingan Range covering most of Ninghsia Province and touching the northern boundaries of the Hopeh, Shansi and Shensi provinces. The area is characterized by sand dunes, solonchaks and the so-called neutral or slighly alkaline chestnut soils. Typical steppe grasses include Achnatherum splendens, Agropyron cristatum, Aneurolepidium pseudoagropyrum, Cleistogenes squarrosa, Elymus dahuricus, Koeleria gracilis and many species of Stipa. Shrubs and dwarf trees may also be present. These typically include Artemisia adamsii, A. desertorum, A. frigida, A. halodendron, A. sacrorum, A. sibirica, Caragana microphylla and various species of Atriplex and Ephedra. Also present are various legumes like Astragalus melitotoides, Glycyrrhiza uralensis, Lespedeza dahurica and Thermopsis lanceolata. Shrub diversity, however, increases in the sand dunes areas of the northeast. Here species such as Agriophyllum arenarium, Atraphaxis mandshurica, Crataegus dahurica, Juniperus chinensis, Malus buccata, Oxytropis psammocharis and Ribes diacantha can be found. Trees are largely absent but adjacent to rivers and other water bodies Populus cathayana, P. euphratica, P. simonii, Salix matsudana and Ulmus pumila may occur and Pinus sylvestris var mongolica can be found on stabilized sand dunes. In extreme desert, steppe with short Stipa species predominates including the endemic Stipa gobica (Poaceae). Notable forbs here include Allium mongolicum, Lagochilus ilicifolius, Gypsophila desertorum, Ptilotrichum canescens, Scorzonera divaricata, Tanacetum achilleoides and Rheum nanum.
Mongolian Scrub Steppe
In areas like the basins of the Great Lakes and the Ordos Plateau scrub dominated by species of Caragana (such as C. korshinskii, C. microphylla or C. pygmaea) and / or species of Reumuria (such as R. kaschgarica, R. songarica or R. trigyna). Associated species include Amygdalus pedunculata, Artemisia xerophytica, Atraphaxis frutescens and Oxytropis aciphylla, while endemics or near endemics include Artemisia ordosica (Asteraceae), Asparagus gobicus (Asparagaceae) and Tetraena mongolica (Zygophyllaceae). The Ordos Plateau is surrounded by meanders of the Yellow River in the southern part of Inner Mongolia and forms the northern margin of the Loess Plateau. The shrubby vegetation has been divided in to about 28 community types mostly dominated by endemic or locally endemic plants. In the harshest parts of this steppe desert shrubs species such as Convolvolus tragacanthoides, Oxytropis aciphylla and the endemic Ammopiptanthes mongolicus (Fabaceae), Potaninia mongolica (Rosaceae) and Tetraena mongolica (Zygophyllaceae) predominate. Here both shrubs and herb cover is sparse; perennial herbs are rare but annual species may occur in patches following summer rain. Most of the above species can also be found in the less harsh depressions where higher moisture levels occur, but in addition other shrubs such as Caragana intermedia, C. stenophylla, C. tibetica, Reaumuria soongorica, Zygophyllum xanthoxylon and the endemic Prunus mongolica (Rosaceae) make an appearence. Here shrub cover is more extensive and there is usually a well-developed herb layer. Other endemic shrub species that may be encountered include Artemisia ordosica (Asteraceae).
Mongolian Forest Steppe
This formation extends over the loess highlands of Kansu, Ninghsia, Shansi and Shensi provinces and ranges from the alluvial plains of the Yellow River to the loess plateau. In the remaining natural stands the calcareous soils support a sparse flora which includes Andropogon ischaemum, Cleistogenes serotina, C. squarrosa, Dicranostigma leptopodum, Rosa hugonis, R. xanthina, Stipa bungeana and S. grandis. In the many eroded valleys species such as Lycium chinense, Hippophae rhamnoides, Prinsepia uniflora, Sophora vicifolia and Zizyphus sativa predominate. True forest, on the other hand, only occurs at higher elevations where more humid conditions prevail. Here the forests are deciduous and include tree species such as Acer ginnala, A. mono, Betula chinensis, B. japonica, Corylus heterphylla, Euonymus alata, Lonicera ferdinandii, Populus davidiana, Tilia paucicostata, Ulmus japonica and U. pumila. At even high elevations on the high mountains these forests gave way to various gymnoperms such as Abies orientalis, Biota orientalis, Picea asparata and P. neoveitchii. In Chinese herbalism Biota orientalis is one of the 50-fundemental herbs and is unusual among gymnosperms in undergoing viviparous germination.
Mongolian Brackish Depressions
Certain places such as the Tsaidam Basin are mostly composed of brackish depressions (inland saltmarsh) known locally as tsaidam. In fact, an ancient sea once filled the Tsaidam Basin. Typical species include Tamarix ramoisissima, Myricaria alopecuroides, Nitraria schoberi, Ceratoides papposa, Halogeton glomeratus, Cynomorium songarium and Lepidium perfoliatum. In other saline (solonchak) areas other halophytes may predominate. Typical species in the well-drained areas include Atriplex sibiricum, Kalidium latifolium, Kochia sieversana, Lepidium latifolium, Nitraria schoberi, Salsola collina, Scorzonera mongolica and Suaeda glauca, whereas in the watter areas Glaux maritima, Phragmites communis, Puccinellia tenuiflora, Scirpus maritimus, Triglochin palustre and Typha davidiana predominate. In the transition zones between saline and non-saline areas the grasses Aneuralepidium pseudo-agropyrum and Puccinellia distans become characteristic. The endemics here are few in number but include Calligonum zaidamense (Polygonaceae) and Salsola zaidamensis (Chenopodiaceae).
Further information required.
References
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