米老排(Mytilaria laosensis)叶C、N、P化学计量比的季节动态与异速生长关系

研究植物生态化学计量特征,有助于了解植物体内C、N和P的分配规律及确定限制植物生长的元素。以广东云浮3年生米老排人工林为研究对象,分析了叶C、N、P含量及其化学计量季节特征,探讨了元素间的异速生长关系。结果表明:C、N和P含量的年平均值分别为497.82 g/kg、21.95 g/kg和0.98 g/kg;C:N,C:P,N:P的年平均值分别为:22.98,527.64,23.06;叶的C含量及C:N、C:P、N:P比的变化趋势为先降低后升高再降低,而N、P含量的变化趋势相反。叶片的年平均N:P高于中国年平均水平(16.3)。叶C、N和P具有显著的异速生长关系(N-C1.839, p=0.000;N-P0.708, p=0.000;C-P2.865, p=0.021)。研究表明,3年生米老排生长主要受P元素限制,对本研究区及时补充P肥有助于米老排的生长。本研究为米老排的生产实践和经营管理具有现实指导意义。

Seasonal Dynamics of Leaf C,N and P Stoichiometric Rations of Mytilaria laosensis and Allometric Relationship

Studies on the eco-stoichiometric characteristics of plants are helpful to grasp the distribution of C, N and P and to determine the elements that restrict the growth of plants. This paper takes the 3-year-old Mytilaria laosensis from Yunfu, Guangdong province as the research objects. The seasonal dynamics of C, N, P and their stoichiometry in the leaves of the research object had been analyzed, and taking the allometric growth relationship between elements into consideration. The results show that the annual average values of C, N and P are 497.82 g/kg,21.95 g/kg and 0.98 g/kg respectively, while the annual average values of C:N, C:P and N:P were 22.98, 527.64,23.06. The C content of leaves and the change trend of C:N, C:P, N:P ratios were first decreased, then increased and ultimately decreased, while the changes of N and P contents were opposite. The annual average value of N:P in the leaves is higher than the annual average of China(16.3). C, N and P in leaves had significant allometric growth relationships(N-C1.839, p=0.000;N-P0.708, p=0.000;C-P2.865, p=0.021). Studies have shown that the growth of 3-yearold Mytilaria laosensis is mainly restricted by P element, and the timely supplementation of P fertilizer in this area will help the growth of Mytilaria laosensis. This study has practical guiding significance for the production practice and management of Mytilaria laosensis.