摘要
The soil landscape relationship was investigated in the Upper Urumqi River Basin of the Tiens-han Mountain Range. Xinjiang,China.Cryosols occurred in glaciated valleys and north-facing toeslopesat elevations above 3 000 m.Most cryosols developed in moraine are Aquiturbels. The microrelief isdominated by earth hummocks, thus the surface organic layers are either discontinuous or broken due tofrost action. The Bg horizons are either gleyed or mottled and frost-churned organic matter is common inthe lower Bg horizons. Stratified horizons and buried organic or A horizons are also common on gentlesloping or undulating moraines indicating the effects of gelifluction. Reticular structures formed in thelower activc layers due to ice lens formation and freeze-thaw cycles.The active layer thickness rangesfrom 140~200 cm. The organic cryosols (Hemistels) occur in depressions and north-facing toeslopeswith an active layer thickness ranging from 90~110 cm. Soils formed on south-facing slopes have a mol-liv epipedon20~25 cm thick and a strong brown cambic horizon and are classified as Haplocryolls.Thedistribution of cryosols is smaller as compared with the extent of permafrost due to the depth requirementof permafrost in cryosol classification. However, the existence of permafrost at greater depth cannot beignored in land use interpretations.