AUTHOR=Guan Ming , Pan Xiao-Cui , Sun Jian-Kun , Chen Ji-Xin , Kong De-Liang , Feng Yu-Long TITLE=Nitrogen acquisition strategy and its effects on invasiveness of a subtropical invasive plant JOURNAL=Frontiers in Plant Science VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1243849 DOI=10.3389/fpls.2023.1243849 ISSN=1664-462X ABSTRACT=Introduction

Preference and plasticity in nitrogen (N) form uptake are the main strategies with which plants absorb soil N. However, little effort has been made to explore effects of N form acquisition strategies, especially the plasticity, on invasiveness of exotic plants, although many studies have determined the effects of N levels (e.g. N deposition).

Methods

To address this problem, we studied the differences in N form acquisition strategies between the invasive plant Solidago canadensis and its co-occurring native plant Artemisia lavandulaefolia, effects of soil N environments, and the relationship between N form acquisition strategy of S. canadensis and its invasiveness using a 15N-labeling technique in three habitats at four field sites.

Results

Total biomass, root biomass, and the uptakes of soil dissolved inorganic N (DIN) per quadrat were higher for the invasive relative to the native species in all three habitats. The invader always preferred dominant soil N forms: NH4+ in habitats with NH4+ as the dominant DIN and NO3- in habitats with NO3- as the dominant DIN, while A. lavandulaefolia consistently preferred NO3- in all habitats. Plasticity in N form uptake was higher in the invasive relative to the native species, especially in the farmland. Plant N form acquisition strategy was influenced by both DIN levels and the proportions of different N forms (NO3-/NH4+) as judged by their negative effects on the proportional contributions of NH4+ to plant N (fNH4+) and the preference for NH4+ (βNH4+). In addition, total biomass was positively associated with fNH4+ or βNH4+ for S. canadensis, while negatively for A. lavandulaefolia. Interestingly, the species may prefer to absorb NH4+ when soil DIN and/or NO3-/NH4+ ratio were low, and root to shoot ratio may be affected by plant nutrient status per se, rather than by soil nutrient availability.

Discussion

Our results indicate that the superior N form acquisition strategy of the invader contributes to its higher N uptake, and therefore to its invasiveness in different habitats, improving our understanding of invasiveness of exotic plants in diverse habitats in terms of utilization of different N forms.