Element-specific scaling between green and senesced leaf nutrient concentrations in mangrove forests

This dataset was generated to test the hypothesis that elemental concentrations in senesced leaves scale systematically with those in green leaves, and that these green-to-senesced scaling relationships vary among elements and may be modified by plant functional attributes, tidal position, season, and species identity. We expected that sublinear scaling would indicate a declining proportion of nutrients retained in senesced leaves as green-leaf nutrient concentrations increase, whereas isometric scaling would indicate proportional coupling between green- and senesced-leaf concentrations. The dataset contains 80 observations from ten mangrove species sampled in Dongzhaigang National Nature Reserve, China, during the dry and wet seasons. For each observation, paired green- and senesced-leaf elemental concentrations are provided for 12 elements: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), sodium (Na), and aluminum (Al). The dataset also includes species identity, tidal position (high or low), growth form (tree or shrub), leaf structure (bifacial or isobilateral), salt-tolerance strategy (secretor or non-secretor), season, and the mass-loss correction factor (MLCF) used in nutrient-resorption calculations. Variables beginning with “Green” represent concentrations in mature green leaves, whereas variables beginning with “Sen” represent concentrations in senesced leaves. The data show positive relationships between green- and senesced-leaf concentrations for all 12 elements. Green-to-senesced scaling was predominantly sublinear for N, P, K, Mg, Fe, Mn, Cu, Na, and Al, indicating that the proportion of these elements retained in senesced leaves decreased as green-leaf concentrations increased. Ca, Zn, and B showed approximately isometric scaling. Functional and environmental effects were selective: scaling differed for P between growth forms; for N and Ca between leaf structures; for P, Ca, and Mg among salt-tolerance strategies; for Na between tidal positions; and for Fe, Cu, and B between seasons. Species-specific variation was detected only for Mg. These data can be used to quantify green-to-senesced elemental scaling, evaluate nutrient resorption and internal nutrient conservation, compare functional or environmental groups, and assess how variation in green-leaf nutrient status is translated into senesced-leaf and litter nutrient concentrations. When interpreting the data using log–log allometric models, a scaling exponent below 1 indicates sublinear scaling, an exponent near 1 indicates approximately isometric scaling, and an exponent above 1 indicates superlinear scaling.