Renping Jiang, Ping He, Jingyang Cheng, Hao Wu, Wenwen Liu, Yihui Zhang

Biological Invasions

https://doi.org/10.1007/s10530-025-03634-0

Published: 22 July 2025

Abstract

The allometric relationships among plant traits designate the morphological developmental trajectories and resource allocation strategies of plants. Invasive plants can develop more competitive traits due to enemy release, occupying a wide range of latitudes, but it remains unclear whether these traits still follow the similar allometric trajectories and how allometry responds to environmental changes and contributes to invasion. Here we conducted field sampling of multiple traits to examine variations in allometry of the salt marsh grass Spartina alterniflora across latitudes in the invasive (20–41°N) and native (27–43°N) ranges. We found that the invasive and native populations maintained similar allometric relationships among multiple traits. Furthermore, allometric relationships exhibited substantial latitudinal fluctuation, and neither significant latitudinal patterns nor differences of the patterns between ranges were observed. Notably, geographical variation in allometric relationships, particularly leaf development, were driven by different environmental factors in the two ranges. The size-dependance of leaf area was affected by tide range and salinity in the invasive range, with greater tide range and higher salinity enhancing the relative increase in leaf area with respect to plant size. These results indicate that stable plant allometry and its pre-adaptation pattern across latitudes may facilitate invasion in novel environments. Additionally, the distinct environmental drivers within each range suggest that potential local adaptation may exist in invasive plant allometry.