Fluctuations in resource availability shape the competitive balance among non‐native plant species

Abstract

Fluctuating resource availability plays a critical role in determining non‐native plant invasions through mediating the competitive balance between non‐native and native species. However, the impact of fluctuating resource availability on interactions among non‐native species remains largely unknown. This represents a barrier to understanding invasion mechanisms, particularly in habitats that harbor multiple non‐native species with different responses to fluctuating resource availability. To examine the responses of non‐native plant species to nutrient fluctuations, we compared the growth of each of 12 non‐native species found to be common in local natural areas to nutrients supplied at a constant rate or supplied as a single large pulse in a pot experiment. We found that seven species produced more biomass with pulsed nutrients compared to constant nutrients (hereafter “benefitting species”), while the other five species did not differ between nutrient enrichment treatments (hereafter “non‐benefitting species”). To investigate how nutrient fluctuations influence the interactions among non‐native plant species, we established experimental non‐native communities in the field with two benefitting and two non‐benefitting non‐native species. Compared with constant nutrient supply, the single large pulse of nutrient did not influence community biomass, but strongly increased the biomass and cover of the benefitting species and decreased those of the non‐benefitting species. Furthermore, the benefitting species had higher leaf N content and greater plant height when nutrients were supplied as a single large pulse than at a constant rate, whereas the non‐benefitting species showed no differences in leaf N content and were shorter when nutrients were supplied as a single large pulse than at a constant rate. Our results add to the growing evidence that the individual responses of non‐native species to nutrient fluctuation are species‐specific. More importantly, benefitting species were favored by nutrients coming in a pulse, while non‐benefitting ones were favored by nutrients coming constantly when they grew together. This suggests that nutrient fluctuations can mediate the competitive balance among non‐native plants and may thus determine their invasion success in a community harboring multiple non‐native plant species.

Perspectives of invasive alien species management in China

“…This study provides valuable insights into the management of invasive plants in changing environments. Additionally, Tao et al (2023) revealed diverse responses to nutrient pulses among alien species, with certain species gaining advantages while others did not. Importantly, in a community context, nutrient fluctuations promoted the success of advantaged species.…”

Responses of non‐native and native plant species to fluctuations of water availability in a greenhouse experiment

“…The importance of fluctuating resource availability for non‐native plant invasions has been confirmed by a large number of experimental evidence in terms of nutrients. For example, compared to nutrients supplied constantly, multiple small pluses and a single large pulse strongly increased the ratio of non‐native plants in the native communities (Parepa et al., 2013 ; Tao et al., 2021 ) or promoted non‐native plants growth when they grew individually (Liu & van Kleunen, 2017 ; Tao et al., 2023 ). In addition to nutrients, water is vital for the survival, growth, and reproduction of terrestrial plants (Castillioni et al., 2022 ; Eziz et al., 2017 ; Mojzes et al., 2020 ).…”

Effects of biochar application and nutrient fluctuation on the growth, and cadmium and nutrient uptake of Trifolium repens with different planting densities in Cd-contaminated soils

“…Due to human-driven global change, most terrestrial ecosystems are experiencing great fluctuations in resource availability ( Li et al., 2022 ; Tao et al., 2023 ). The fluctuating resource can influence the growth of plants directly by changing the nutrient uptake ( Warren et al., 2003 ), or indirectly by affecting the activities of soil microbes ( Carrero-Colón et al., 2006a ; Carrero-Colón et al., 2006b ), and then subsequently affects the heavy metal uptake of plants.…”