not-yet-known not-yet-known not-yet-known unknown Leaf nutrient resorption efficiency (NuRE) serves as a metric for delineating plant strategies that range from ‘slow-fast’ performance to conservative-acquisitive resource management. However, the relationships between the interspecific variations in NuRE and the economic traits of both leaves and roots remain unclear. In this study, we gathered both green and senesced leaves to explore mass-based nitrogen (N) and phosphorus (P) concentrations, as well as leaf structural investment and root economic traits, across 10 tree and shrub species within mangrove ecosystems in Hainan, China. This study challenges the initial hypothesis by revealing that species with low leaf structural investment, indicated by low leaf mass per area and leaf dry matter content, exhibit high N and P resorption efficiency. These findings suggest that plants with less investment in the leaf structure are more efficient at resorbing nutrients. Contrary to expectations, root economic traits such as specific root length, root nitrogen content, root diameter, and root tissue density did not significantly influence NuRE. These findings indicate that above-ground nutrient conservation mechanisms may function independently of root foraging traits. This study highlights mangroves’ key role in nutrient recycling, enhancing our grasp of plant dynamics and their impact on global cycles, especially in coastal areas.

1. The relationship between plant size and trait characteristics is a fundamental aspect of the global spectrum that encompasses plant form and function. However, it remains unclear whether plant size affects interspecific variation in leaf structural traits at a specific ontogenetic stage. 2. In this research, we investigated the leaf structural traits, plant height, and diameter at breast height (or basal diameter) of 10 shrub and tree species. This study was carried out along an intertidal gradient within a mangrove forest located in Southeast China. 3. We found that leaf traits differed significantly between shrubs and trees in their response to intertidal gradients, which contributes to the advancement of our understanding of plant adaptive strategies and the evolution of traits within varying environmental contexts. Among all species, leaf carbon economics (leaf dry mass content, leaf mass per area, and leaf density) decreased significantly with increasing plant height and diameter. For each growth form and intertidal zone, the plant size-trait patterns were consistent with those in the pooled dataset. 4. Collectively, these findings suggest that mangrove plants undergo a size-dependent shift from resource conservation to resource acquisition strategies with increasing stature. Therefore, plant size serves as an indicator of the “slow-fast” spectrum of plant performance and the dichotomy between conservation and acquisition strategies.