Global patterns in leaf stoichiometry across coastal wetlands

Abstract

Aim Coastal wetlands provide crucial ecosystem functions and services, such as coastal protection, nutrient retention and C sequestration. Despite the important roles in global C, N and P cycling, the global variation in leaf stoichiometry across coastal wetlands remains unclear. Location Global. Time period 1980–2018. Major taxa studied Vascular plants. Methods By compiling a global dataset of 698 data records in 205 sites, we carried out systematic analyses of the world‐wide trends and their determinants of leaf element contents and ratios of plants across coastal wetlands. Results Leaf N and P contents increased significantly, but C:N, C:P and N:P ratios decreased with increasing latitude in coastal wetlands. The mean annual temperature was the predominant driver of leaf N, P and C:N, whereas soil N:P was a good predictor of leaf C:P and N:P ratios. Furthermore, N increased faster with P in plant leaves of coastal wetlands compared with terrestrial ecosystems. Within coastal wetlands, herb‐dominated salt marshes had a significantly higher leaf P content, lower leaf N:P ratio and lower scaling exponent of leaf N to P than tree‐dominated mangroves. Main conclusions The similar latitudinal patterns of leaf stoichiometry in coastal wetlands compared with terrestrial ecosystems reflected the similar influences of temperature. However, different slopes of leaf P and N:P ratios and N and P scaling relationships between these two ecosystems suggested that different salinity and tidal inundation levels result in different strategies of N and P use in coastal wetland plants. These differences in leaf stoichiometry between ecosystems and between different types of coastal wetlands might need to be emphasized in future biogeochemical modelling owing to their different roles in global nutrient and carbon cycling.

Soil Carbon, Nitrogen, and Phosphorus Stoichiometry and Fractions in Blue Carbon Ecosystems: Implications for Carbon Accumulation in Allochthonous-Dominated Habitats

“…Significant positive relationships were observed between soil and plant N/P ratios in all three ecosystems (Figure S1), suggesting that plant N/P ratios highly depend on soil nutrient status. 41,42 In general, high soil and plant N/P ratios co-occurred in the OC-rich soils of the United States of America and Belize (Figure 1b and Figure S2), and more strikingly, these ratios were well-constrained in low levels in OC-poor soils of China (Figure 1b). In China, BCE soil average C/P and N/P ratios were 4−8fold and 4−5-fold lower than their global means, and the plant C/P and N/P ratios and maximum C/N ratios were also relatively low (Table S3), indicating strong N limitation in OCpoor BCEs.…”

Carbon, Nitrogen, and Phosphorus Stoichiometry and Plant Growth Strategy as Related to Land-Use in Hangzhou Bay Coastal Wetland, China

“…Coastal wetlands have extremely high biodiversity and productivity, and play vitally important functions that cannot be replaced by other ecosystems ( Hu et al, 2021 ). However, global changes, such as reclamation or plant invasion due to human activity, have already change the land-use and degraded and damaged ecosystem functions ( Ma et al, 2014 ).…”

Contrasting global patterns and trait controls of major mineral elements in leaf

“…For foliar K, Ca, Mg, Cu and Na, latitudinal trends were similar to that of N and P, implying that both the plant physiological hypothesis and soil substrate age hypotheses regarding N & P could be extended to above‐mentioned elements (Du et al, 2020; Hu et al, 2021; Woods et al, 2003). Concentrations of these elements in leaf increased with latitude and/or decreased with higher MAT (Figures 3 and 4), in line with the former mechanism which predicts increasing levels of nutrients in cold‐exposed tissues to compensate the slowdown of biochemical reactions (Woods et al, 2003; Xie et al, 2022).…”