Studies have indicated that consistent or well-constrained (relatively low variability) carbon:nitrogen:phosphorus (C:N:P) ratios exist in large-scale ecosystems, including both marine and terrestrial ecosystems. Little is known about the C, N and P stoichiometric ratios that exist in the soils and plants of Chenier Island in the Yellow River Delta (YRD). We examined the distribution patterns and relationships of C, N and P stoichiometry in the soils and plants of Chenier Island, as well as the potential influences of the island’s micro-geomorphology. Based on a study of four soil profile categories and Phragmites australis and Suaeda heteroptera plant tissues, our results showed that micro-geomorphology could leave a distinct imprint on the soil and plant elemental stoichiometry of Chenier Island; significant variation in the atomic C:N:P ratios (R_CNP) existed in soils and plants, indicating that the R_CNP values in both the soil and plants are not well constrained at the Chenier Island scale. R_CN and R_CP in Chenier Island soils were high, whereas the R_NP values were comparatively low, indicating that the ecosystems of Chenier Island are nutrient-limited by N and P. However, the R_NP values in P. australis and S. heteroptera plant tissues were high, suggesting that the plants of Chenier Island are nutrient-limited by P. Finally, we suggest that soil and plant N:P ratios may be good indicators of the soil and plant nutrient status during soil development and plant growth, which could be a useful reference for restoring the degraded soils of Chenier Island.

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.

The water–sediment regulation scheme (WSRS), initiated in 2002, induced an impulse delivery of freshwater and sediment within 10–20 days. In this scenario, the Yellow River turbid plumes (YRPs), which serve as indicators of the marine dispersion of terrestrial materials, displayed substantial spatio-temporal variations. However, the extension patterns of the YRP and their dynamic mechanisms on an interannual scale remain poorly understood. Using multi-source high-resolution imageries, the YRP variations were examined during 2003–2023. The results revealed that the WSRS significantly increased the extensions of the YRP, with its area expanding annually from 67.41 ± 25.27 to 162.54 ± 39.03 km². Additionally, three distinct diffusion patterns were identified: I) a frequent prototypical spreading along the direction of river channel expansion, II) rightward spreading toward Laizhou Bay, and III) leftward spreading toward Bohai Bay. River discharge was identified as the primary driver controlling the plume extension, followed by wind, which primarily modulated the plume orientations. Furthermore, several unique plume extension patterns were observed under episodic weather events.