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[目的]研究8种亚热带常见园林树种叶片N、P、K内吸收率及其季节变化。[方法]分别采用扩散法、钼锑抗比色法和火焰光度计法对采集叶片N、P、K含量进行测定。[结果]各树种成熟叶养分含量都高于新鲜凋落叶,且大部分呈显著性差异,N、P、K的内吸收率(平均值±标准差)分别为(9.11±3.89)%~(68.42±2.44)%、(9.94±5.31)%~(60.54±13.74)%和(24.66±12.14)%~(77.15±5.21)%。N和K的内吸收率有显著性差异(P<0.05),N和P以及P和K之间差异并不显著;N和P的内吸收率春季低于秋季,K的内吸收率春季高于秋季;常绿树种和落叶树种的养分内吸收率无显著差异;固氮树种(羊蹄甲和黄槐)与非固氮树种的N内吸收率也未出现显著差异。[结论]植物叶片在凋落前发生内吸收作用是一种比较普遍的现象,季节变化只是影响植物叶片养分内吸收的主要因素之一,不同的生活型并没有显著影响植物的内吸收率,固氮作用对植物在N养分供给上作用并不明显。
[Objective] The research aimed to study the N, P, K absorption rate and its seasonal variation in eight common subtropical garden tree species. [Method] The contents of N, P and K in leaves were determined by diffusion method, molybdenum antimony colorimetric method and flame photometer method respectively. [Result] The nutrient contents of mature leaves of all species were higher than those of fresh litter, and most of them showed significant difference. The internal absorption rates (mean ± standard deviation) of N, P and K were (9.11 ± 3.89)% ~ 68.42 ± 2.44%, (9.94 ± 5.31)% ~ (60.54 ± 13.74)% and (24.66 ± 12.14)% ~ (77.15 ± 5.21)%, respectively. There was a significant difference in internal absorption rates between N and K (P <0.05), but N and P, P and K were not significant. The internal absorption rates of N and P were lower in spring than in autumn, In the autumn, there was no significant difference in nutrient uptake between the evergreen and deciduous species, and there was no significant difference in the N uptake rate between the nitrogen-fixing species (Acorus hooboensis and Sophora japonica) and the non-nitrogen-fixing species. [Conclusion] The internal absorption of plant leaves before litter was a common phenomenon. Seasonal changes were only one of the main factors affecting plant leaf nutrient absorption. Different life forms did not significantly affect the plant internal absorption rate. Nitrogen fixation The role of the role of plants in the N nutrient supply is not obvious.