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Populus euphratica, Tamarix ramosissima, and Sophora alopecuroides are, respectively, typical arboreal, shrubby, and herbaceous species in oases of arid regions. It is important to study the difference in metabolic characteristics of the rhizosphere fungal community of these plant species and their relationships with soil factors for the preservation of delicate arid oasis ecosystems with future environmental changes. In this study, we, respectively, collected 18 rhizosphere soil samples of P. euphratica, T. ramosissima, and S. alopecuroides to explore the difference in rhizosphere fungal metabolic characteristics of different plant life forms and their underlying driving factors. The results showed that (1) soil physicochemical properties (including soil water content, pH, etc.) were significantly different among different plant species (p < 0.05). (2) Rhizosphere fungal metabolic characteristics were significantly different between S. alopecuroides and T. ramosissima (ANOSIM, p < 0.05), which was mainly caused by the different utilization of carboxylic carbon. (3) The RDA showed that the main driving factors of the variations in rhizosphere fungal metabolic characteristics were different among different plant species. The main explanatory variables of the variations in the metabolic characteristics of the rhizosphere fungal community were carbon to nitrogen ratio (23%) and available potassium (17.4%) for P. euphratica, while soil organic carbon (23.1%), pH (8.6%), and total nitrogen (8.2%) for T. ramosissima, and soil clay content (36.6%) and soil organic carbon (12.6%) for S. alopecuroides. In conclusion, the variations in rhizosphere fungal metabolic characteristics in arid oases are dominantly affected by soil factors rather than plant life forms. [ABSTRACT FROM AUTHOR]

A method is proposed to estimate the threshold wind speed for dust emissions as a function of soil moisture in arid regions. This method, which is applicable at the local scale, employs a model of the surface heat budget to estimate the spatial distribution of thermal inertia-derived soil moisture (TISM) and an analytical footprint model to estimate dust source areas. It incorporates readily available satellite and meteorological data. The soil moisture inside the dust source area is estimated for individual dust phenomena observed at a synoptic surface observation site, and then, together with the corresponding observed wind speed, the threshold wind speed as a function of soil moisture is found by employing the parametrization of Fécan et al. (Ann Geophys 17:149–157, 1999). This relationship represents the local dust climatology at the observation site, although the data include some outliers. The results show that readily available data for the natural environment can be used, as an alternative to wind-tunnel data, with the parametrization used to derive the threshold wind-speed relation. The derived relation indicates the TISM and wind speed at which the probability of a dust phenomenon is 10%. Moreover, the threshold wind-speed results are not sensitive to the principal footprint-model parameters. The TISM standard error of approximately 0.04 m3 m−3 could significantly affect the results under dry and weak-wind conditions, but this sensitivity can be avoided if the soil clay content or the soil type at the observation point is known. [ABSTRACT FROM AUTHOR]