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以黄土高原幼龄林、中龄林、成熟林(分别为5~10、11~15、21~30年生)刺槐人工林为对象,研究刺槐根、茎、叶、枯落物的碳、氮、磷化学计量学特征及其相互关系.结果表明:不同林龄刺槐林各组分的碳、氮、磷含量分别为376.74~486.67、8.66~29.70和0.79~1.95g·kg~(-1),刺槐各组分碳含量变异较小,磷含量变异较大.中龄林碳含量较高,成熟林氮、磷含量较高.不同组分间叶碳、氮、磷含量较高,茎的氮含量较低.不同林龄刺槐林各组分的C/N、C/P和N/P分别为15.74~53.40、242.47~606.39和8.10~20.57;中龄林和幼龄林中茎C/N、C/P和N/P显著高于成熟林,不同组分间茎C/N、C/P较高,叶C/N、C/P较低.刺槐叶片和根的碳氮磷含量间不存在相关关系,枯落物与茎的氮含量和磷含量间存在显著相关关系,反映出枯落物和茎的建成过程中对氮磷按比例投入的依赖.与全球尺度相比,黄土高原人工刺槐林具有较高的储碳能力,氮含量丰富,而磷相对缺乏,成为刺槐人工林生长的主要限制因子.
The Robinia pseudoacacia plantations in young, middle-aged and mature forests (5 ~ 10, 11 ~ 15, 21 ~ 30 years old) in Loess Plateau were used to study the effects of carbon and nitrogen on the root, stem, , Phosphorus chemometrics and their relationships were studied.The results showed that the contents of carbon, nitrogen and phosphorus in the components of Robinia pseudoacacia forest were 376.74 ~ 486.67, 8.66 ~ 29.70 and 0.79 ~ 1.95g · kg -1, , The Robinia pseudoacacacana varities were smaller and the content of phosphorus was bigger.The content of carbon in the middle-aged forest was higher, while the content of nitrogen and phosphorus in the mature plant was higher.The contents of carbon, nitrogen and phosphorus in different components were higher, The nitrogen content was lower.The C / N, C / P and N / P of each component of Robinia pseudoacacia forest with different stand ages were 15.74 ~ 53.40, 242.47 ~ 606.39 and 8.10 ~ 20.57, respectively.The stem C / N, C / P and N / P in R. pseudoacacia were significantly higher than those in mature forest, with higher C / N and C / P ratios and lower C / N and C / There is no correlation between litter and stem nitrogen content and phosphorus content is significantly related to reflect the formation of litter and stems on the proportion of nitrogen and phosphorus into the dependent.Compared with the global scale, Plateau Artificial Robinia has a higher forest Capability of carbon, nitrogen-rich, and the relative lack of phosphorus, a major factor limiting the Growth of Robinia pseudoacacia.