Shifts in composition and diversity of arbuscular mycorrhizal fungi and glomalin contents during revegetation of desertified semiarid grassland

Abstract Arbuscular mycorrhizal (AM) fungi may facilitate the revegetation of degraded ecosystems by decreasing abiotic and biotic stresses on pioneer plants. In addition to assessing the AM status of pioneer plants, monitoring the dynamics of an AM fungal community after revegetation can provide key information for the selection of plant-AM fungal combinations that adapt to the disturbed conditions to promote the establishment and growth of mycorrhizal-dependent pioneer plants. Accordingly, species composition, diversity, and spore density of the AM fungal community inhabiting the root zones of 12-year- and 30-year-old planted Caragana microphylla were determined in the desertified grassland in northern China. Moreover, the content of glomalin-related soil proteins (GRSP) was measured to assess AM fungal biomass. A total of 23 AM fungal species belonging to Acaulospora , Claroideoglomus , Dentiscutata , Funneliformis , Glomus , Rhizophagus , and Septoglomus , were identified. Soil phosphorus availability or organic-carbon content significantly affected AM fungal composition and diversity. However, edaphic properties can explain only approximately 30% of the variations in the AM fungal community. Spore density and GRSP content recorded at the 30-year revegetated dune were significantly higher than those at the 12-year revegetated dune. No significant differences in community composition and diversity of AM fungi were recorded at the dunes with different revegetation duration. This indicates that there might be a certain degree of host-specificity existing in the C. microphylla -AM fungal association. Both taxonomic and phylogenetic analyses should be performed in further research to obtain comprehensive information about the composition and dynamics of an AM fungal community during revegetation of the desertified grassland.