Interactions between soil and exotic plant species
Recent studies have shown that invasive alien plant species can alter the soil conditions in which they grow through allelopathy. The resulting positive feedback(s) may provide a competitive advantage for the exotic species over native plant species enabling them to utilize resources more efficiently and thus persist and dominate an area. A meta-analysis has been conducted on plant-soil feedbacks in exotic plant species across life forms. Over 200 scientific papers were sourced from the Web of Science and Scopus using a combination of relevant keywords. Following analysis, the authors show that in general exotic plant species enhance carbon cycling and populations of soil invertebrates and nematodes. Overall, native and exotic plant species showed neutral feedback effects in soil conditioned by plants of the other origin. However, there were differences when comparing life forms; native trees were negatively affected in soil conditioned by exotic trees whereas native grasses were positively affected in soil conditioned by exotic grasses.
Meisner A, Gera Hol WH, de Boer W, Krumins JA, Wardle DA, van der Putten WH (2014) Plant-soil feedbacks of exotic plant species across life forms: a meta-analysis. Biological invasions 16, 2551-2561.