Comparative nutrient concentration and resorption dynamics in petals and leaves

Chemical elements support various plant functions, and their reutilization is important for plant ecological adaptation. However, there is a lack of studies comparing the elemental concentration and their reutilization in floral petals and leaves of the same plant. To address this research gap, we conducted a comparative study across 38 plant species with diverse life forms in a common garden. Our investigation focused on the nutrient concentration of 10 elements in both petals and leaves and functional traits, including flower lifespan, dry mass per unit area, water concentration, and vein density. We have found that the elements of nitrogen (N), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) were more abundant in leaves. In contrast, petals contained higher concentrations of phosphorus (P) and potassium (K). N, P, K, Ca, Mg, and sodium (Na) concentrations of petals were positively related to leaves. In herbaceous plants, their petals showed significant resorption of P and K, while N, P, and K were detected with significant resorption in leaves from all life forms. A positive correlation was found between the resorption of P in leaves and petals. From the perspective of the carbon economic spectrum, N and P showed a negative correlation with dry mass per unit area in leaves. Meanwhile, petal dry mass per area and floral longevity were significantly negatively correlated with P. Our findings elucidate the nutritional basis for the functional differentiation between petals and leaves.