Do arbuscular mycorrhizal fungi help the native species Bidens biternata resist the invasion of Bidens alba?

Abstract

Arbuscular mycorrhizal fungi (AMF) play an important role in competition between exotic and native species, but we know little about the role of AMF in changing plant intra- and interspecific competition. Invasive alien species Bidens alba and native species Bidens biternata were selected. Five species proportions, 0:4, 1:3, 2:2, 3:1, and 4:0, of B. alba: B. biternata were examined to simulate inter- and intraspecific competition between the two plants. Glomus mosseae was selected as the AMF inoculum. The results showed that B. alba strongly inhibited B. biternata, and the effects of inhibition increased as the proportion of B. alba increased with up to 71% reduction in both shoot and root biomass. When inoculated with Glomus mosseae, the biomass of the two plants significantly increased, and B. biternata was no longer inhibited by B. alba, conversely B. biternata showed stronger competitiveness under the species proportion of B. alba: B. biternata = 1:3. This suggests AMF have the potential to help the native species B. biternata resist the invasive species B. alba under certain proportion. Under competition with the invasive species B. alba, AMF facilitated phosphorus (P) absorption of the native species B. biternata, whereas such facilitation by AMF decreased sharply under B. biternata monoculture. Our study indicates that AMF can alter the competitive relationship between native and invasive species through affecting the absorption of P between plants, and the role of AMF is associated with the inter- and intraspecies competition.