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Background and aims: Plant community stability is threatened by anthropogenic climate changes such as increased precipitation. Arbuscular mycorrhizal (AM) fungi have been shown to drive the resistance of ecosystems against climate changes to provide stable ecosystem functions. However, how AMF affects plant community stability under climate change is still not sufficiently clear in Central Asia. Methods: A comprehensive study was conducted with increased precipitation and suppression of AMF in mycorrhizal and non-mycorrhizal plant communities, respectively. Changes in plant community composition and aboveground biomass were measured, and the temporal stability of plant community was calculated. Results: Mycorrhizal plant community responded more sensitively to the increased precipitation and suppression of AMF than non-mycorrhizal plant community. Species synchrony and population variability were only significantly changed by increased precipitation in the mycorrhizal plant community. The stability of dominant and mycorrhizal plants were positively related to community temporal stability of both plant communities. While contrasted with the positive effects of increased precipitation on community temporal stability, increased precipitation reduced community temporal stability by increasing temporal variations of plant biomass in the mycorrhizal plant community, and by decreasing plant diversity in the non-mycorrhizal plant community. However, AMF buffer the decreases in community stability by increasing plant community biomass under increasing precipitation. Conclusion: Our findings highlight ongoing increases in precipitation potentially weaken the temporal stability of ephemeral plant communities in the desert ecosystem stability; however, AMF can alleviate these negative effects through increasing community biomass, especially in the plant community dominated by mycorrhizal species. [ABSTRACT FROM AUTHOR]

Background and aims: The encroachment of halophytic shrubs including tamarisk into saline meadows is accelerating with global warming in the northern Tarim Basin, Xinjiang, China. However, the role of tamarisk in the spatial heterogeneity of soil resources in different desertification stages remains unclear. Methods: The influences of tamarisk on soil resources were assessed via soil salinity and soil organic matter (SOM) measurements under tamarisk canopies and in interspaces. Geostatistical methods were applied to compare the spatial heterogeneity of these soil properties in three regions representing different desertification stages: 1) a meadow with shrubs, 2) a shrubland and 3) shrub duneland. Results: The highest coefficient of variation (CVs) of the soil analytes and most developed 'resource islands' were observed in the shrubland. The overall variation of most of the soil variables was lower in the shrub duneland than in the shrubland and similar to that in the meadow with shrubs. The distribution of SOM and most soil salinity ions were moderately spatially dependent in the meadow with shrubs but highly spatially dependent in the shrubland and shrub duneland. The autocorrelation distances of the most of soil salinity ions were approximately 6- to 15- fold and 2- to 4-fold highest than the tamarisk shrub size in the meadow with shrubs and shrubland, respectively. In contrast, the distribution range of total soil salinity (TSS) and soil K, Na and Cl in the shrub duneland were 1/5 ~ 2/3 of the tamarisk size. Conclusions: 1) Compared with the effect of tamarisk on soil resource heterogeneity in the meadow with shrubs, that in the shrubland was enhanced due to the larger shrub size and more open and scattered canopy in the latter.2) Although the largest shrub size were observed in the shrub duneland, the role of tamarisk in redistributing soil resources was overriden by those of physical processes due to the loose canopy. 3) The spatial heterogeneity of soil resources is determined by not only tamarisk but also environmental factors, such as the connectivity of bare areas and topography. [ABSTRACT FROM AUTHOR]