Isotopic signatures offer new methods, approaches, and perspectives for exploring the ecological adaptability and functions of plants. We examined pattern differences in the isotopic signatures (δ¹³C, δ¹⁵N, δ³⁴S) of Spartina alterniflora across varying plant life-death statuses along geographic clines. We extracted 539 sets of isotopic data from 57 publications covering 268 sites across a latitude range of over 23.8° along coastal wetlands. Responses of isotopic signatures to climate drivers (MAT and MAP) and the internal relationships between isotopic signatures were also detected. The latitudinal patterns of δ¹³C, δ¹⁵N, and δ³⁴S in S. alterniflora were shaped as a convex curve, a concave curve, and an increasing straight line, respectively. A decreasing straight line for δ¹³C within the ranges of MAT was identified under plant life status. Plant life-death status shaped two nearly parallel decreasing straight lines for δ³⁴S in response to MAT, resulting in a concave curve of δ³⁴S for live S. alterniflora in response to MAP. The δ¹⁵N of S. alterniflora significantly decreased with increasing δ¹³C of S. alterniflora, except for plant death status. The δ¹³C, δ¹⁵N, and δ³⁴S of S. alterniflora are consistent with other traits, showing general latitudinal patterns closely related to MAT. Plant life-death status altered the δ¹⁵N-latitudinal patterns of S. alterniflora and their responses to MAT, demonstrating strong ecological plasticity and adaptability across the geographic clines.

Latitudinal pattern, biological invasion, isotope signature, coupling relationship