Eco-stoichiometric Characteristics of Carbon, Nitrogen and Phosphorus in Leaves and Soil of Camellia oleifera at Different Age

The 3-year, 6-year, 9-year, and 30-year-old Camellia oleifera plantations in Changshan County, Zhejiang Province were used as the research objects. The carbon, nitrogen and phosphorus contents and stoichiometric ratios of C. oleifera leaves and soils were analyzed. The results show that there is no significant difference in the carbon content of C. oleifera leaves among different forest ages. The nitrogen content of the 9-year-old leaves is significantly higher than that of the 3-year-old, and the phosphorus content shows that the 9-year-old and 30-year-old leaves are significantly higher than the 3-year-old. The C∶N of the 3-year-old leaves is significantly higher than that of the 9-year-old, and the C∶P shows that the 3-year-old leaves are significantly higher than the 9-year and 30-year-old. The soil organic carbon content increases with age, and the soil organic carbon content in the surface soil of 9-year-old and 30-year-old C. oleifera forests is significantly higher than that in 3-year-old. The soil nitrogen and phosphorus contents decrease with the increase of forest age. The soil phosphorus content of the 3-year and 6-year-old C. oleifera forests is significantly higher than that of the 30-year-old, and the soil nitrogen content of the soil layer of 10-30 cm is significantly higher than that of the 30-year-old. Soil C∶N, C∶P increase with the increase of forest age, and there are significant differences among different forest ages. Except N∶P, the soil carbon, nitrogen and phosphorus contents and their stoichiometric ratios of the same forest age oil tea decreased with the increase of soil depth. There is a significant positive correlation between nitrogen and phosphorus content in leaves and soil organic carbon content. There is a significant positive correlation between leaf carbon content and surface soil nitrogen content, while leaf nitrogen and phosphorus contents are significantly negatively correlated with surface soil nitrogen content. The limiting element for the growth of C. oleifera is nitrogen. In the process of production and management, nitrogen fertilizer can be appropriately added.