亚热带4种林木幼苗的碳氮磷含量及其化学计量比特征

Carbon,nitrogen,and phosphorus contents in four tree seedlings of subtropical plants and their stoichiometric ratio characteristics

以亚热带区域4种主要森林植物杉木(Cunninghamia lanceolata)、马尾松(Pinus massoniana)、木荷(Schima superba)、米槠(Castanopsis carlesii)幼苗为研究对象,分别测定其不同器官碳(C)、氮(N)、磷(P)含量,并计算其化学计量比.结果表明:(1)针叶树种C、N含量以及C/P、N/P高于阔叶树种,P含量及C/N则低于阔叶树种.(2)杉木叶片N、P含量及茎P含量高于马尾松,但各器官的C/N与C/P低于马尾松;米槠根N含量、C/P、N/P高于木荷.(3)4种林木幼苗的C、N含量及C/P、N/P均以叶为最高,根的C、N含量为最低,茎的C/P和N/P为最低;P含量以茎为最高,叶为最低;C/N以根为最高,叶为最低.本研究结果可为我国湿润亚热带区域森林植物苗木培育、幼林养分管理及人工造林时立地选择等提供参考价值.

This study aimed to explore the stoichiometric characteristics of different plant organs of subtropical plants. The C, N, and P contents in tree seedlings of four dominant forests （i.e. Cunninghamia lanceolata, Pinus massoniana, Schima superba, and Castanopsis carlesii, respectively） were measured in different organs, and C, N, and P stoichiometric ratios were calculated. （1） C and N contents, as well as C/P and N/P ratios in coniferous forests, were higher than those in broad-leaved forests, while the P content and C/N ratio followed the opposite trend. （2） Leaf N content, as well as leaf and stem P content in C. lanceolata forests were higher than those in P. massoniana forests, while the C/N and C/P ratios in each organ of P. massoniana forests were higher than those of C. lanceolata forests. Root N content, C/P ratio, and N/P ratio of C. carlesii were higher than those of S. superba. （3） In general, C and N contents, as well as C/P and N/P ratios in the leaf were the highest; the stem contained the highest P content, whereas the leaf contained the lowest P content; the C/N ratio in the root was the highest, while that in the leaf was the lowest. These results reveal the C, N, and P stoichiometry of four tree seedlings in a subtropical moist area, providing a valuable reference for the site selection of artificial afforestation.