黄浦江中上游广玉兰人工林生态系统碳储量特点

Carbon Storage of Magnolia Grandiflora Plantations in Upper and Middle Reaches of Huangpu River, Shanghai

广玉兰是我国亚热带地区常见绿化树种之一。本研究以上海黄浦江中上游广玉兰人工林为研究对象,构建了广玉兰林木及各器官(根、干、皮、枝、叶)生物量方程,并估测了广玉兰人工林林分生物量(乔木层、凋落物层)、碳储量和土壤碳储量。研究结果表明,广玉兰立木及各器官的生物量方程拟合效果较好(R2 = 0.90~0.99,P 。9年生广玉兰人工林生态系统总碳储量为59.9 t·hm?2。在广玉兰人工林林分总碳储量中,乔木层碳储量所占比例为23.4%,其中,广玉兰立木各组分碳储量大小排序为树干 >树根 >树叶 >树枝 >树皮。凋落物层碳储量所占比例仅为1.5%。土壤碳储量(0~30 cm)所占比例最大,为75.1%。这些广玉兰人工幼龄林正处于生长旺盛阶段,对上海地区人工林碳汇经营具有重要意义。

Magnolia grandiflora is one of the most common evergreen tree species in subtropical area in China. In this study, three plantations were studied and allometric equations for different organs such as root, trunk, bark, branch and foliage of M. grandiflora were established in the upper and middle reaches of Huangpu River in Shanghai area. The carbon storage of tree biomass, forest floor and soils (0-30 cm) were estimated in three 9-year-old stands. The results showed that there was a significant relationship between individual biomass and the diameter at breast height for the allometric equation in each organs, with the coefficient of determination R2 = 0.90 - 0.99, P ?2. In the total carbon storage of the poplar tree stands, tree biomass carbon storage proportionally accounted for 23.4%, and each organ was ranked as: trunk >root >foliage >branch >bark. The forest floor accounted for 1.5%. The soil is the biggest part which accounted for 75.1%. This result indicated that the poplar young plantations currently are at fast-growing stage, which has an important role for carbon sequestration management in Shanghai.