论文部分内容阅读
以巨桉人工混交林不同树种为研究对象,分析了巨桉及伴生树种红椿、台湾桤木、檫木的叶片、凋落叶和相应土壤的C、N、P化学计量特征。结果表明:不同树种叶片、凋落叶、土壤N∶P分别为6.7~9.7、8.6~9.7和1.6~4.0,C∶N分别为29.6~62.8、78.4~101.8和15.3~19.5,C∶P分别为279.9~459.3、639.0~795.9和24.9~77.6;4个树种中,檫木具有最高的C储存能力和N、P利用效率;伴生树种凋落叶的C∶N、C∶P低于巨桉,说明伴生树种凋落叶的可分解性更强,引入伴生树种会加快混交林的N、P循环速率;所有树种叶片N∶P<10,说明混交林4个树种较大程度上受N限制且巨桉受N限制的情况更突出,混交林中不同树种土壤N、P含量及化学计量特征具有显著的差异,引入伴生树种可改变巨桉人工林生态系统的养分循环;随着林龄的增加,伴生树种在巨桉人工林生态系统养分循环中的正效应会体现得更加明显。
Taking the different species of Eucalyptus grandis plantation as the research object, the C, N and P stoichiometric characteristics of the leaves, litter and relative soil of Eucalyptus grandis and its associated species Toona sinensis, Alnus mandshurica and Alnus mandshurica were analyzed. The results showed that the N:P of different species were 6.7 ~ 9.7, 8.6 ~ 9.7 and 1.6 ~ 4.0 respectively, the C: N values were 29.6 ~ 62.8, 78.4 ~ 101.8 and 15.3 ~ 19.5, 279.9 ~ 459.3, 639.0 ~ 795.9 and 24.9 ~ 77.6, respectively. Alnus cremastogyne had the highest C storage capacity and N, P utilization efficiency; the C: N and C:P of the litter associated trees were lower than that of E. grandis The decomposition of associated tree litter was stronger, and the introduction of associated species accelerated the N and P cycling rate of mixed forest. The N:P <10 of all tree species indicated that the four tree species in mixed forest were largely limited by N and Eucalyptus grandis Under the N limitation, the N and P contents and stoichiometry of different tree species in mixed forest were significantly different. Introduction of associated tree species could change the nutrient cycle of Eucalyptus grandis plantation ecosystem. With the increase of age, The positive effect of tree species in the nutrient cycle of Eucalyptus grandis plantation ecosystem will be more obvious.