Matthew effect: common species become more common and rare ones become more rare in response to artificial light at night

Abstract

Artificial light at night (ALAN) has been and still is rapidly spreading, and has become an important component of global change. Although numerous studies have tested its potential biological and ecological impacts on animals, fewer have tested its impacts on plants, and very few studies have tested whether it affects alien and native plants differently. Furthermore, common plant species, and particularly common alien species, are often found to benefit more from additional resources than rare native and rare alien species. Whether this is also the case with regard to increasing light due to ALAN is still unknown. Here, we tested how ALAN affects the performance of common and rare alien and native plants directly and indirectly via flying insects. We grew five common alien, six rare alien, five common native and four rare native plant species under four combinations of two ALAN (no ALAN vs ALAN) and two insect-exclusion (no exclusion vs exclusion) treatments, and compared their biomass production. We found that common plant species, irrespective of whether they are alien or native, produced significantly more biomass than rare species, particularly under ALAN. Furthermore, alien species tended to show a slightly stronger positive response to ALAN than native species (marginally significant origin x ALAN interaction, p = 0.079). Our study shows that common plant species benefited more from ALAN than rare ones. This might lead to shifts in plant diversity and vegetation composition, further propelling global biodiversity decline, when ALAN becomes more widespread. In addition, the slightly more positive response of alien species indicates that ALAN might increase the risk of alien plant invasions.