The successful invasion of alien plants is comprehensive effects of its intrinsic advantages and environmental factors. Many studies have revealed that the effects of light, phosphorus, and arbuscular mycorrhizal fungi (AMF) on the invasive plants. The environment of plant growth is usually a combination of multiple factors. Results of single factor study are difficult to reveal the impact of natural environment on invasive plants. T. repens
Linn., a typical invasive plant, was used as the research object. This study examined the effects of light, phosphorus, AMF and their interactions on growth and physiological traits of T. repens.
with a three-factor and two-level orthogonal experiment on light (yes/no shading), P (high/low) and AMF (yes/no inoculation). The results show that: (1) Ambient sunlight, high P and inoculation of AMF significantly increased the biomass and growth rate of the T. repens
, high P and inoculation of AMF decreased the biomass promotion effect with shading, and low P was conducive to the positive effect of AMF on the relative growth rate of the T. repens
; (2) excepted for the specific leaf area, light significantly increased the number of leaves, leaf mass fraction, total leaf area and leaf thickness, while high P and AMF significantly increased the number of leaves, leaf mass fraction and total leaf area, and the promotion effect was weakened with shading; (3) Shading significantly reduced the root surface area, root diameter and root mass fraction, and increased the proportion of fine roots and specific root length. Low P significantly increased the root mass fraction and fine roots proportion, but significantly reduced the root surface area under shading. AMF significantly reduced root diameter and specific root length, and increased the negative effect of shading. AMF significantly increased root surface area and root diameter under low P, and significantly reduced the proportion of fine roots. These results indicate that P and AMF had a significant effect on the above and below ground traits of the T. repens
, and dependent on light intensity. The effect size of AMF on the belowground traits of the T. repens
was also dependent on P concentration. The results of this study have profound implications for understanding the effects of multiple factors on invasive plants.