Ecological Stoichiometric Characteristics and Adaptive Strategies of Herbaceous Plants in the Yellow River Delta Wetland, China

The content and stoichiometric ratios of plant biogenic elements are key indicators for understanding plants' ecological traits and their responses to environmental changes. However, it remains unclear how wetland herbaceous plants allocate these biogenic elements and how they relate to soil conditions. This study examines the variations in carbon (C), nitrogen (N), and phosphorus (P) stoichiometry across different organs and life forms, and their response to soil factors in Yellow River Delta wetlands. We analyzed the stoichiometric characteristics of 44 herbaceous species (17 annuals and 27 perennials) and their organs (leaves and stems). The results showed that annual plants show higher N and P but lower C content compared to perennials, indicating distinct life history strategies. In plant organs, leaves exhibited higher C, N, and P concentrations than stems, reflecting functional adaptation. Notably, random forest analysis identified stem C content as a key indicator for life history strategy differentiation. Furthermore, soil factors directly influenced organ-level stoichiometry but showed limited effects across life forms. The plants demonstrated P limitation with high sensitivity to soil P availability. This study provides new insights into organ-specific nutrient allocation strategies in wetland plants and offers valuable guidance for coastal wetland conservation.