Abstract:Nutrient resorption is a key component of nutrient conservation strategies and productivity and element cycling in ecosystems. It influences many, if not most, ecosystem processes, including carbon cycling and resource-use efficiency, plant litter decomposition through changes in litter quality, and plant competition. We studied 15 species of evergreen woody plants and 14 species of deciduous woody plants in a limestone area in Chongqing; compared leaf dry matter content (LDMC), specific leaf area (SLA), and leaf thickness (LT) of two different types of plants before and after leaf senescence; and analysed leaf nutrients and resorption characteristics before and after senescence by using different calculation methods (nutrient content per unit mass and leaf nutrient content per unit area). Finally, we analysed the correlation between nutrient resorption efficiency and other leaf traits. The results showed that LDMC and LT were significantly higher in the mature leaves of evergreen species than in those of deciduous species in the Chongqing karst area. SLA and SLA in senesced leaves were significantly lower in evergreen plants than in deciduous plants; LT was significantly higher in evergreen plants than in deciduous plants; and LDMC showed no significant difference. Nutrient content per unit mass of leaves, leaf nitrogen concentration (LNC), and leaf phosphorus concentration (LPC) were higher in the mature leaves of evergreen species, and LNC in senesced leaves was significantly lower in evergreen plants. Nutrient content per unit area of the leaves showed the opposite trend: LNC and LPC were lower in the mature and senesced leaves of evergreen species. There was no significant difference in the N to P ratio (greater than 16) in both mature and senesced leaves of the two types of plants. There was no significant difference in N and P resorption efficiency calculated using different methods, and both evergreen and deciduous species showed lower resorption efficiency. When nutrient resorption efficiency was calculated on the basis of unit mass of leaves, mean N and P resorption efficiency for evergreen species was 39.42% and 43.79%, respectively, and that for deciduous species was 24.08% and 33.59%, respectively. When nutrient resorption efficiency was calculated on the basis of per unit area of leaves, mean N and P resorption efficiency for evergreen species was 39.32% and 45.19%, respectively, and that for deciduous species was 29.59% and 38.45%, respectively. There was no significant correlation between N and P resorption efficiency and LDMC, SLA, LT, and N and P contents in the mature leaves of the two types of plants. However, N and P resorption efficiency was negatively correlated with nutrient content in senesced leaves. This indicated that lower the nutrient content in senesced leaves, higher the nutrient resorption efficiency, that is, higher the degree of resorption of nutrients, higher the nutrient resorption efficiency. In this study, we found that N and P contents were both low in evergreen and deciduous plants, indicating that plants in a limestone area have higher nutrient resorption efficiency.