| Popis: |
Mangrove species are undergoing environmental changes from nutrient-poor to nutrient enrichment due to the large input of external nutrients. The potential difference in adaptive strategies between the slow- and fast-growing species may lead to great changes in species interaction and ecosystem functioning. This study aims to test whether the response strategies to soil nutrient availability differ between the slow- and fast-growing mangrove species. The comparison was carried out among three common mangrove species including two slow-growing species Aegiceras corniculata and Kandelia obovata, and one intrinsic fast-growing species Laguncularia racemosa. All tested species showed conservative strategies (such as slow-growing and high concentrations of leaf tolerance/resistance traits) when living in the nutrient-poor soils. But when soil nutrient increased, L. racemosa shifted to a fast-growing strategy, accompanied by a substantial reduction of tolerance traits including the concentrations of carbon, cellulose, total phenolics, and soluble sugar in leaves. In contrast, A. corniculatum and K. obovata maintained still conservative strategies even under nutrient enrichment. All the species increased leaf nitrogen, phosphorus, lipid, lignin and specific leaf area (SLA) with soil nutrient availability, but L. racemosa showed a greater nutrient acquisition capacity indicated by a steeper regression line of SLA vs. nutrient resorption efficiency than A. corniculatum. Further, the steeper regression line of SLA vs. leaf δ13C of L. racemosa indicated a higher water use efficiency than A. corniculatum. The dependence of the adaptive strategies of these species to soil nutrient status improved the standing of plant-plant interactions at different soil nutrient status. |
