To study the retranslocation efficiency between mature and senescing needles, the needle macronutrient concentrations (N, P, K, Ca, Mg) were measured in four Chinese fir plantations with various ages (8, 14, 21, 46 years old, respectively) in subtropical China. The results showed that the nutrient concentrations( without Mg) of mature needles differed significantly among different ages of Chinese fir, and did not show regular rule. However, the concentrations of N, K, Mg did not fluctuate significantly among senescing needle with tree ages. The retranslocation efficiency of these five macronutrients in Chinese fir with different ages were presented on an order of REK>REP>REN>REMg>RECa , and Ca element was transferred from mature to senescing needles. The translocation efficiency of N, K, Mg did not varied significantly among different ages of Chinese fir. A significantly positive correla-tionship between P, K, Ca, Mg in the mature needle and retranslocation efficiency were found by using regression analysis while the macronutrient in senescing needle were negative correlated with retranslocation efficiency. In conclusion, our results suggested that mobilization of macronutrient from senescing to mature needle may represent a survival strategy adapted to Chinese fir with different ages, and this characteristic did not change with the increase of forest age.
Chinese firneedlemacronutrientnutrient retranslocation efficiencynutrient content in foliagenutrient internal cycling
国家科技期刊平台
NSTL
维普
万方数据
