不同林龄杨梅叶片与土壤的碳、氮、磷生态化学计量特征

为了解不同林龄杨梅（Myrica rubra）叶片和土壤的碳（C）、氮（N）、磷（P）生态化学计量特征，以浙江省仙居县3、9、14和21年生的杨梅人工林为对象，研究了杨梅叶片和土壤的碳（C）、氮（N）、磷（P）含量及化学计量比。结果表明，杨梅叶片碳、氮含量在不同林龄间无差异，3年生叶片磷含量显著高于14年和21年生（P<0.05），21年生叶片C∶P显著高于3年和9年生（P<0.05）。土壤有机碳、全氮和全磷含量均随着林龄的增大表现为先降低而后升高。3年生杨梅林土壤有机碳含量显著高于其他年龄（P<0.05），土壤全氮、全磷含量显著高于9年生（P<0.05）。土壤C∶N、C∶P及N∶P在不同林龄间没有差异。同一林龄杨梅土壤碳氮磷含量及其化学计量比总体表现为随土层深度增加而降低。叶片氮含量与土壤全氮具有显著正相关（P<0.05）。杨梅生长的限制元素是磷，在生产经营过程中，可适当增施磷肥。

The stoichiometic characteristics of carbon, nitrogen and phosphorus in soil and leaves of different ages of Myrica rubra

Myrica rubra is a unique and ever-green fruit-tree in China. To explore the ecological stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in leaves and soil of Myrica rubra under different forest ages, this paper studied the content and stoichiometry of C, N and P in leaves and soil, based on the different age groups of Myrica rubra (3 a, 9 a, 14 a and 21a) in Xianju County, Zhejiang Province. The results indicated that: (1) there was no significant difference in the C and N contents of Myrica rubra in leaves between different forest ages, while the P content in 3-year-old leaves was significantly higher than that in 14- and 21-year-old ones (P<0.05), and the C:P in leaves of 21-year-old of Myrica rubra was significantly higher than that of 3- and 9-year-old groups (P<0.05); (2) with the increase of cultivation ages, the contents of soil organic C, N and P decreased firstly and then increased, the soil organic C content in the treatment group of 3-year-old of Myrica rubra was significantly higher than groups of other ages (P<0.05), and the N and P contents in the soil of 3-year-old group were significantly higher than that of 9-year-old group (P<0.05); (3) there were no significant differences in the ration values of soil C:N, C:P and N:P between different forest age groups, and the nitrogen contents in leaves were positively correlated with the nitrogen content in soil (P<0.05). In conclusion, the limiting element affecting the growth of Myrica rubra is P, so in the process of production, P fertilizer should be properly added.