Stress-resistance traits disrupt the plant economics - decomposition relationship across environmental gradients in salt marshes

Understanding how plants respond to environmental gradients and influence ecosystem functions remains a core challenge in ecology. Across species ecosystems, have been shown coordinate leaf, stem, root traits along gradient with optimal resource acquisition or conservation strategies at its extremes, termed the plant economic spectrum (PES), turn driving functioning. PES theory has successfully applied coastal wetlands disentangle strong abiotic affect functions, such as litter decomposition. Yet, can be dominated by monospecific stands, it unclear whether applies within species. Here, focusing on globally widespread salt marsh plant, Spartina anglica , we investigated: a) if holds intraspecific level critical stress (redox potential soil salinity); b) changes decomposition; c) these abundance of key macro-detritivores, mediating We found remarkable variation S. leaf stem traits, coordinating adopting conservative strategy under stronger stress. Unexpectedly, leaves (higher dry matter content C/N ratio) attracted more macro-detritivores decomposed faster. Other facets quality beyond seem drive counter-intuitive effects: were likely palatable because higher protein lower toughness (low total carbohydrate content). Our study highlights that trait variability strongly decomposition, potentially impacting carbon storage capacity marshes; specific stress-resistance disrupt - function relationship. • Leaf (PES). Under adopt strategy. Counter-intuitively, decompose Plant related salinity resistance functioning salinity, ultimately increasing decomposition