Author/Authors :
Ye, GF Fujian Academy of Forestry, China , Zhang, SJ Key Pingtan State-owned Protection Forest Farm of Fujian Province, China , Zhang, LH Chinese Academy of Sciences (CAS) - Yantai Institute of Coastal Zone Research (YIC) - Key Laboratory of Coastal Environmental Processes, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, China , Lin, YM Xiamen University - School of Life Sciences - Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, China , Wei, SD Xiamen University - School of Life Sciences - Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, China , Liao, MM Xiamen University - School of Life Sciences - Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, China , Lin, GH Xiamen University - School of Life Sciences - Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, China
Abstract :
Tannin levels and nutrient resorption of Casuarina equisetifolia at different developmental phases (juvenile, mature and senescent phases) were examined to evaluate possible nutrient conservation strategies under nutrient limitation. Results showed that C. equisetifolia branchlets contained relatively higher contents of total phenolics, extractable condensed tannin, total condensed tannin contents and protein precipitation capacity in juvenile stands compared with those in mature and senescent stands. Nitrogen (N) concentrations in mature branchlets increased with stand development, while phosphorus (P) concentrations showed a decreasing trend. Nitrogen:phosphorus ratios in mature branchlets were above 20 and increased with stand development. Phosphorus resorption efficiencies were significantly higher than N resorption efficiencies, with the highest in mature stands. Tannin level, nutrient concentration and resorption were affected by stand age. Our results indicated that at intraspecific level, C. equisetifolia could adjust its nutrient conservation with stand development.
Keywords :
Nutrient limitation , nutrient resorption efficiency , polyphenolics dynamics , stand development
