Drought intensify the effects of warming on root-colonizing arbuscular mycorrhizal fungal community in subtropical Chinese fir plantation

Abstract

Despite the important linkages of AM fungi with plants, the studies regarding the responses of AM fungal community to warming and drought have lagged behind that of the aboveground plants. In this study, we investigated the impacts of four years of warming and drought on the taxonomic and phylogenetic composition of root-colonizing AM fungal communities in a manipulated field experiment in a five year old Chinese fir plantation. The phylogenetic patterns were also used to evaluate the ecological processes structuring AM fungal communities. Results indicated that the diversity of AM fungi remained relatively stable after the four years of warming and drought. Variations in the taxonomic and phylogenetic composition of AM fungal community were recorded under warming but not drought treatments. Under drought conditions, warming made the largest pronounced effects on AM fungal community composition. A decrease in the Glomeraceae abundance and increase in the Gigasporaceae abundance were found to primarily contribute to the differences in the AM fungal community composition between control and warming treatments. In addition, AM fungal communities were phylogenetically clustered across all experimental treatments, suggesting that environmental filtering such as selection by host plants was the primary ecological process structuring the root-associated AM fungal community assembly. Overall, these findings supported that warming exerted significant effects on the root-colonizing AM fungal communities, especially under drought conditions, but not changed the ecological processes responsible for the assembly of AM fungal communities in the subtropical region.