关键词: 马尾松, 养分循环, 养分利用效率, 轮伐期, 长江口, 棘头梅童鱼, 种群参数, 资源状况

Abstract: By using a chronosequence approach, this paper studied the nutrients accumulation, allocation, and cycling in 7-, 17-, 31-, and 51-year-old Masson pine plantations, aimed to analyze the dynamics of nutrients in Masson pine plantation at its different developmental stages. The results showed that 1) nutrient accumulation was not synchronized with biomass accumulation, with the accumulation rate of biomass being 3.3, 5.4, 3.3, 3.7, and 9.8 times of that of N, P, K, Ca, and Mg from age 17 to 51, respectively, 2) nutrient allocation to a specific component was related to the growth rate of the nutrient pool in the component, and the nutrient allocation to stem as well as the ratio of nutrient allocation to root/shoot increased with plantation age, and 3) the biomass production per unit nutrient, i.e., nutrient use efficiency, and the nutrient cycling coefficient also increased with plantation age, being higher for 51-year-old plantation than for younger plantations, suggesting that shortening the rotation length could reduce the possibility to raise the nutrient use efficiency. It was suggested that both extending the current rotation length to as long as 50 years and reducing the harvest intensity could be helpful to conserve the nutrients and to maintain long-term productivity.

Key words: Masson pine (Pinus massoniana), nutrient cycling, nutrient use efficiency (NUE), rotation length, Yangtze estuary, Collichthys lucidus, population parameters, resource situation.