Effects of arbuscular mycorrhizal fungi on root foraging and competitive ability between native and invasive plants

Abstract

Background and Aims Besides the direct uptake of nutrients by roots, plants can acquire nutrients through the aid of arbuscular mycorrhizal fungi (AMF). AMF play a crucial role in plant growth and competitive abilities. However, few studies have investigated the effects of AMF on root-foraging, and their interactive effects on competition between native and invasive species in response to heterogeneous nutrients. Methods Two invasive plants and their two co-existing native plants of the Asteraceae family were selected to create a common garden experiment involving three factors (heterogeneous vs. homogeneous phosphorus, with vs. without AMF inoculation, and monoculture vs. mixture). Results AMF significantly reduced the foraging scale of the invasive species, Bidens pilosa, and decreased the precision of the invasive species, Praxelis clematidea, and the native species, Emilia sonchifolia. There were significant interactive effects of AMF and phosphorus heterogeneity on plant biomass and nutrient uptake. Heterogeneity significantly decreased the tolerance ability of B. pilosa but increased that of P. clematidea. In the homogeneous treatment, AMF significantly decreased the suppression ability of B. pilosa, while in the heterogeneous treatment, AMF decreased that of P. clematidea. Heterogeneous phosphorus with AMF increased the suppression relative interaction intensity of B. pilosa but decreased that of P. clematidea. Conclusion The interactive effects of AMF and phosphorus heterogeneity on root foraging and competitive abilities differ between invasive and native plants and show invasive-native pair differences. These findings provide valuable insights into the interactive effects of AMF and roots on nutrient uptake and competition in different nutrient distributions.