不同林龄马尾松针叶凋落前后养分含量及回收特征

以湖南会同地区10、23和45年生马尾松人工林为研究对象,采用不同参数(单位质量养分含量、单位长度养分含量和单叶养分含量)分析了针叶凋落前后养分含量及回收特征.结果表明：3个林龄马尾松针叶凋落后的单叶质量、单叶长度和单位长度质量平均分别下降了15.9%、4.6%和13.9%；不同林龄针叶养分含量不同；凋落前马尾松单叶N、P、K回收平均在50%以上；养分再吸收效率和转移度均随林龄先增后减.除N外,基于不同参数计算所得养分再吸收效率差异不明显.

Nutrient contents and resorption characteristics in needles of different age Pinus massoniana (Lamb.) before and after withering.

Taking the 10-, 23-, and 45-year-old Pinus massoniana plantations in Huitong of Hunnan Province as test objects and with the parameters nutrient content per unit needle mass, nutrient content per unit needle length, and nutrient content of single needle, the nutrient contents and resorption characteristics in the needles of different age P. massoniana before and after withering were studied. The results showed that after withering, the mass of single needle, length of single needle, and mass per unit needle length were decreased by 15.9%, 4.6% and 13.9%, respectively. The nutrient contents in the needles differed with the age of P. massoniana, and the mean resorption of N, P and K in the needles was all higher than 50%. With the increase of tree age, the nutrient resorption efficiency and proficiency increased first and declined then. According to the calculations with the parameters mentioned above, there was no significant difference in the resorption efficiency of the nutrients except N.