不同林龄杉木养分重吸收率及其C∶N∶P化学计量特征

Nutrient Resorption Efficiency and C∶N∶P Stoichiometry of Cunninghamia lanceolata Plantations with Different Ages

为探究不同林龄杉木成熟叶与衰老叶之间的重吸收率及其C∶N∶P化学计量特征,以8、14、21、46年生杉木为研究对象,测定并计算其鲜叶、凋落叶和表层土壤的养分含量、重吸收率及其C∶N∶P化学计量比。结果表明:1)不同林龄间叶片C、N含量差异显著(P<0.05),叶片、凋落叶P含量差异性均极显著(P<0.01),14年生杉木叶片N含量显著高于其他3个年龄的树木(P<0.05),呈单峰型;2)较高的C∶N、C∶P比是植物对养分较高利用率的体现,杉木鲜叶养分含量均与其重吸收率均呈负相关,N、P利用效率在一定范围随N、P含量的升高而降低;3)本区植物N、P重吸收率分别在33.89%~38.40%和37.49%~46.35%之间,P重吸收率>N,且不同林龄杉木成熟鲜叶N∶P>16,表明该地区杉木的生长可能受到P元素限制。

To explore nutrient resorption efficiency and C ： N = P stoichiometry of Cunninghamia lanceolata plantations with different ages, 8-, 14-, 21-, and 46-year-old C. lanceolata trees were used as research objec- tives. Nutrient contents in the fresh mature leaves, fallen leaves, and facial soil were measured. The rate of resorption and C ： N ： P stoichiometry were calculated. The results showed that 1） the contents of C, N and P in the trees was significantly higher than those in soil. The differences in the contents of C and N between the trees with different ages were significant （P〈0.05） ,P contents in the fresh leaves and litter groups