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Revegetation is a widely used way to minimise aeolian sediment transport in desertified land. An optimal vegetation density and planting pattern reduces the economic investment for revegetation and competition for limited water resources. This study aimed to ascertain the effects of vegetation density and planting pattern on aeolian sediment transport at the regional scale. A series of wind tunnel tests were implemented with artificial shrubs representing Haloxylon ammodendron. These tests were designed with three planting densities (i.e., 600 plants ha−1, 1200 plants ha−1, and 1650 plants ha−1) and four patterns (uniform distribution, random distribution, two rows/one belt, and one row/one belt pattern). Geostatistical interpolation methods available in ArcGIS were used to analyse the spatial variation of sand heights. Vegetation density and planting pattern and their interaction all significantly affected the aeolian sediment transport but vegetation density had the greatest impact. With increasing density of vegetation, wind erosion rate decreased significantly following quadratic function, and wind erosion still occurred around the artificial shrubs regardless of vegetation density and planting pattern. For wind erosion rate, erosion and deposition area, the uniform distribution pattern had little protective benefit at the three planting densities, whilst the combinations of the random distribution pattern with 600 plants ha−1, two rows/one belt pattern with 1200 plants ha−1, and one row/one belt pattern with 1650 plants ha−1 had the best protective benefit in controlling the aeolian sediment transport.

Enhancing the resistance of sandy desert soil to drought and wind erosion is key to controlling aeolian desertification. Using biochar as an amendment can improve soil quality. This study aimed to determine the impacts of biochar particle size and application rate on the hydraulic and physical properties of sandy desert soil. Biochars were produced by pyrolyzing corn straw at 500 °C with limited oxygen. Samples of sandy desert soil were collected from the Tengger Desert in Northwestern China. Tests were designed with three biochar particle sizes (0–0.25, 0.25–1, and 1–2 mm) and five biochar application rates (wt%: 0, 0.5%, 1%, 2%, and 4%). Soil hydraulic and physical properties were characterized by the soil–water characteristic curve, soil porosity, soil specific surface area (SSA), and soil structural index (SI). The results showed that biochar significantly increased the soil porosity and the number of extreme micropores, micropores, and small pores. As a consequence, the saturated soil water content ( θ s ), permanent wilting point (PWP), field capacity (FC), and available water content (AWC) were significantly enhanced. The significant improvement in SI demonstrated that biochar enhanced the soil aggregate stability, therefore, the resistance of sandy desert soil to wind erosion is enhanced. Biochar dosage was a more important factor that influenced the FC, AWC, PWP, SI, and SSA of the soil more than biochar particle size. The properties of θ s , PWP, FC, AWC, and SI were all closely related to SSA, indicating that SSA played a key role in the mechanism affecting the response of the soil to biochar application. The significant increase in water retention and aggregate stability of sandy desert soil with added biochar suggests a novel strategy to control aeolian desertification by amending the soil.

Analysis of spatial-temporal variations of desert vegetation under the background of climate changes can provide references for ecological restoration in arid and semi-arid areas. In this study, we used the Global Inventory Modeling and Mapping Studies (GIMMS) NDVI data from 1982 to 2006 and Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data from 2000 to 2013 to reveal the dynamics of desert vegetation in Hexi region of Northwest China over the past three decades. We also used the annual temperature and precipitation data acquired from the Chinese meteorological stations to analyze the response of desert vegetation to climatic variations. The average value of NDVImax (the maximum NDVI during the growing season) for desert vegetation in Hexi region increased at the rate of 0.65×10–3/a (P

Growth and development of plants were always influenced by the combined effects of climate conditions accumulated in the previous periods,which was always explained by the variation of phenological characteristics of plants.With the rapidly increase of average surface temperature over the 20th century,shifts in animal and plant phenology have been widely reported in the northern hemisphere,phenology was now recognized as one of the simplest and most frequently used bio-indicators for studying the climate change.However,there are great differences in the response of plant phenology to the climate change,and which one will be the relatively sensitive meteorological factors to the phenology of plant species,to which time scale the plant species will be responded significantly is still unknown,this make it difficult to accurately predict the responding process of plant species to the climate change.Phenological data of typical herbaceous plants(Lris lacteal) and the corresponding meteorological data were both collected from the Minqin Desert Botanical Garden in 1974—2007,and phenological characteristics of this species was analyzed and its response to the accumulated precipitation and temperature in different time scales were studied.The conclusions were obtained as follows:(1) The growing season length(difference between the starting date of budding period to the ending date of wilting period) of Lris lacteal was about 201.7 days with an increasing rate of 0.8 days per 10 years,which was not statistically significant during 1974—2007(P0.1).(2) Except the starting date(which refers to the time when nearly 50% of the species have experienced a certain phenological event) of the flowering period showed an obvious delay,and was statistically significant,the starting date and the ending date(which refers to the time when most of the species have finished this event) of remaining phenophases all displayed a slight delay,and was not statistically significant.The duration period(days of difference between the starting and ending date of one phenology) of all the phenophases of Lris lacteal varied greatly in different years,in which the duration period of budding period,flowering period and fruiting period all exhibited a decreasing trend,while leafing period and wilting period both showed an increasing trend,all of which were not statistically significant.(3) The extension of growing season lengths of Lris lacteal was attributed to the combined effects of both temperature and precipitation.The starting date of phenophases of this species was greatly influenced by the accumulated temperature from the preceding 3 weeks to 3 months,which was statistically significant at the 95% confidence level,while which has no relations with the accumulated temperature in preceding 1—3 years.Some of the phenophases of this species has a slight response to the accumulated precipitation in short-term and mid-term period,but no influence was found on the accumulated precipitation in the long-term period.(4) Phenophases of Lris lacteal was not only influenced by the local climate change,but also has some relations with its water use mechanisms,climate change in the future may have an great influence on the phenological characteristics of typical herbaceous plants in this desert area.

This paper made researches on the consumer service industry, which is based the empirical study on the travel industry, and explored the interpersonal factors of customer evaluation. From the literatures, we find four interpersonal factors in service encounter; they are: the relationships among customers, the relationships among employees, the similarities between the customers and the employees, and the service quality evaluation of the employee. After empirical study, we got two results: (1) the relationships among the employees and the evaluations of the employees have a significant impact on the customer service quality evaluation; (2) there is not only one simple integrated quality evaluation influencing customers' attitude, but also the relationships among the customers and the degree of the similarity between the customers and the employees-these two factors have independent impact on the customer satisfactions.

This paper made researches on the consumer service industry, which is based the empirical study on the travel industry, and explored the interactive relationships influencing factors. From the literatures, we find four interactive relationships influencing factors, they are: the relationships among customers, the relationships among employees, the similarities between the customer and the employee, and the service quality evaluation of the employee. After empirical study the mutual influencing relationships we got two results: (1) the relationships among the employees and the evaluations of the employees have a significant impact on the customer service quality evaluation, (2) there is not only one simple integrated quality evaluation influencing customers’ attitude, but also the relationships among the customers and the degree of the similarity between the customers and the employees-these two factors have independent impact on the customer satisfactions.