Background: Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats. However, the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats. While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats, our understanding of belowground environment of invasive species in their native habitats is very limited. In this study, we analyzed soil characteristics associated with an exotic invasive plant, Old World Climbing Fern (Lygodium microphyllum), in its native habitat in Australia and the recipient habitat in South Florida. Rhizosphere soil samples from both habitats were analyzed for soil physical, chemical and biological characteristics.
Results: Soil characteristics in the recipient habitats were significantly different compared to those in the native habitats. Soil samples from the native habitat had low soil pH, and high concentrations of elements such as aluminum and zinc which are phytotoxic in acidic soil environments. Additionally, mycorrhizal fungi spores were more diverse in the recipient habitat in Florida compared to the native habitat in Australia.
Conclusion: Overall, our results indicate that growth of an invasive plant in its native habitats could be restricted by the toxic effects associated with strong soil acidity. Results from this study indicate that invasive plants not only escape from their natural herbivores but also from toxic soil environment in their native habitats
