Artificial night-time lighting and nutrient enrichment synergistically favour the growth of alien ornamental plant species over co-occurring native plant species

Insights into ecological drivers of alien plant invasions can be gained through comparative studies of growth and fecundity of invasive alien plants versus those of co-occurring non-invasive alien plants and native plants across environmental conditions in common garden settings. Habitats that harbour alien plant species in many ecosystems globally are presently experiencing light pollution resulting from artificial light at night (ALAN) and increased rates of nutrient enrichment of the soil. However, the potential interactive effects of ALAN and nutrient enrichment on invasiveness of alien plant species remain unknown.
Here, we performed a common-garden experiment to test the interactive effects of ALAN and soil nutrient enrichment on the growth of a random set of 10 alien (five invasive and five naturalized) and seven co-occurring native ornamental plant species that are commonly cultivated within urban and peri-urban areas of Nairobi city in Kenya. We predicted that a simultaneous i...