Nitrogen resorption from leaves under different growth irradiance in three deciduous woody species
Nitrogen resorption from leaves under different growth irradiance in three deciduous woody species
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DOI：
10.1007/s11258-004-2485-8
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发表时间：
2005-05
期刊：
影响因子：
1.7
通讯作者：
Y. Yasumura;Y. Onoda;K. Hikosaka;T. Hirose
中科院分区：
文献类型：
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作者：
Y. Yasumura;Y. Onoda;K. Hikosaka;T. Hirose
衰老叶片对氮的再吸收是一种重要的保护机制，可以使植物重复利用相同的氮。我们测量了在山毛榉森林中共同发生的植物中的N再吸收的程度，以检查N再吸收的变异性，特别是与生长辐照度有关。在三种落叶木本植物中进行了测量;一棵成年树和几棵幼年树，分别是毛豆和几棵成年树，分别是乌药和厚朴。氮再吸收效率（REFF;叶片衰老过程中被吸收的N的百分比）在不同生长光照下没有显著差异，但根际REFF受树体生长阶段的影响，幼龄树的REFF值始终低于成年树。N再吸收能力（RPROF;枯叶N浓度）在钝齿冷杉幼年树和M. salicifolia，而不考虑衰老叶片N浓度的影响，生长光照。此外，RPROF是较低的（即绝对N浓度较高）在幼年树比成年树在F. crenata。这些结果表明，生长光照对氮吸收的程度没有很大的影响，但树木的生长阶段是有影响的一些物种。成年树和幼龄树之间的差异可能归因于N库组织的大小，这可能是随着植物年龄的增加。
Resorption of nitrogen (N) from senescing leaves is an important conservation mechanism that allows plants to use the same N repeatedly. We measured the extent of N resorption in plants co-occurring in a beech forest to examine the variability of N resorption, especially in relation to growth irradiance. Measurements were done in three deciduous woody species; one adult and several juvenile trees ofFagus crenataand several adult trees ofLindera umbellataandMagnolia salicifolia. N resorption efficiency (REFF; percentages of leaf N that is resorbed during leaf senescence) did not differ significantly among leaves under different growth irradiances in any species we studied.REFFwas affected by the growth stage of the tree inF. crenatawith the values being consistently lower in juvenile trees than in the adult tree. N resorption proficiency (RPROF; N concentration of dead leaves) converged to a similar value inF. crenatajuvenile trees andM. salicifolia, irrespective of the presenescent leaf N concentration that was affected by growth irradiance. Again,RPROFwas lower (i.e. absolute N concentration was higher) in juvenile trees than in the adult tree inF. crenata. These results suggest that the growth irradiance does not place a great impact on the extent of N resorption, but the growth stage of the tree is influential in some species. The difference between the adult and juvenile trees may be ascribed to the size of N sink tissues, which is likely to increase with plant age.