Key Role of Desert–Oasis Transitional Area in Avoiding Oasis Land Degradation from Aeolian Desertification in Dunhuang, Northwest China

Abstract

The survival of oasis is partially determined by the evolution of desert–oasis transitional area (abbr. DOTA) characterized by fragile and unstable environments. This study reveals the function of DOTA in avoiding oasis land degradation from its aeolian environments based on the detailed wind data, in situ observation of wind‐blown sand and granular characteristics of surface sediments from desert to oasis. Results indicate that the DOTA has buffering function in slowing down aeolian desertification in oasis. Additionally, the annual mean wind speed reduces 40·8% from desert to DOTA area but up to 92·8% from desert to oasis. The frequency of sand‐laden wind, drift potential and sand transport all decrease following the section from desert to oasis while surface roughness increases. And the granular characteristics of surface sediments show that the weight percentage of coarse sand decreases but fine sand increases along the section from desert to oasis. This paper reveals that the aeolian environments are of great difference between desert and DOTA and the significant role of DOTA in protecting oasis. Integrated sand control system needs to be settled in the DOTA to strengthen its buffering function. Copyright © 2016 John Wiley & Sons, Ltd.

Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China

“…Aeolian geomorphic process is an important factor affecting the distribution desert plants and other factors control the growth stages of plants and vegetation distribution by changing soil conditions (Szczuciński, 2012;Hernández-Cordero et al, 2015;Tang et al, 2016). From desert to oasis, the frequency of sand-laden wind, drift potential, and sand transport decreases while the roughness of surface increases (Zhang et al, 2017). The difference in dynamic aeolian conditions between oasis and desert shapes the dune microtopography, which restricts the distribution of desert plants.…”

“…The oasis-desert ecotone (ODE) is a typical landscape located downstream of inland rivers in arid regions and is influenced by the interaction between the expanding oasis and encroaching desert. It is a key ecological barrier that protects oasis from the hazards of sand storms (Zhang et al, 2017) and is sensitive to human activities and climate changes. Therefore, the ODE is characterized by environmental vulnerability (Pi et al, 2017).…”

Spatial Variation of Soil Seed Bank under Cushion Plants in a Subalpine Degraded Grassland

“…Therefore, we emphasized the prominent role of cushion plants in the conservation of plant diversity in our subalpine grasslands. Although the rangeland managers believe that the cushions should be partly eradicated for enhancement of forage production (unpub., Results), we emphasize that the removal of the cushions not only increases the overland flow and soil erosion (Álvarez‐Martínez et al, ; Symeonakis et al, ; Zhang et al, ) but also decreases SSB density and richness and finally plant diversity. The cushion can act as seed source and seed island for recovery of degraded intensive‐grazed gaps after removal of grazing.…”

Quantifying the effects of human activities and climate variability on vegetation cover change in a hyper‐arid endorheic basin

“…In the arid endorheic basin, water resources were limited, and irrational cropland reclamation led to more water consumption (Montazar, 2013). In the long run, deep groundwater would be end- The oasis-desert is a narrow belt located between the oasis and the neighboring desert in arid area, and it acts an interactive zone between irrigated oasis and natural desert ecosystem (Zhang, An, Cai, Guo, & Xiao, 2017). The oasis-desert transitional zone has a buffering function in slowing down the aeolian desertification in oasis, and it plays a critical role in ensuring oasis ecological security and maintaining oasis ecological stability.…”