Nutrient resorption (NR) from senescing leaves plays an important role in the conservation of nutrients in plants. The nutrient resorption efficiency depends on several factors including availability of soil nutrients, species type and leaf nutrient quality. Although several researchers have worked on the pattern of NR in deciduous and evergreen plants, it varied widely. Since the variations are species-specific and many functional groups prevailing in tropical and subtropical forests have not been studied, the understanding of NR pattern in varied functional groups remained incomplete. In this study, Nitrogen resorption efficiency (NRE) of four tree species belonging to different functional groups viz., Alnus nepalensis (non-leguminous nitrogen-fixing and deciduous), Lithocarpus dealbatus (broadleaved and evergreen), Pinus kesiya (coniferous and evergreen) and Schima wallichii (broadleaved semi-evergreen) were studied. NRE was greatest in Alnus nepalensis and Schima wallichii immediately before the maximum leaf fall and it decreased in the subsequent months. However, NRE in Lithocarpus dealbatus exhibited identical values across all the months in a year. In Pinus kesiya, the NRE was the lowest and it varied through six months. The nitrogen concentration in the leaves and NRE varied significantly among the species and across the months. The trees belonging to certain functional groups did not differ in their NREs in different months of a year due to the availability of alternate strategies to acquire nitrogen or being semi-/ evergreen in nature to cope up with their nutrient loss.

中文翻译：

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梅加拉亚邦亚热带森林树木不同功能组之间氮吸收效率的模式

衰老叶片的养分吸收（NR）在植物营养养护中起着重要作用。养分吸收效率取决于几个因素，包括土壤养分的利用率，物种类型和叶片养分质量。尽管有几位研究人员研究了落叶和常绿植物中的NR模式，但其变化范围很大。由于变异是特定于物种的，并且尚未研究热带和亚热带森林中盛行的许多功能组，因此对各种功能组中的NR模式的理解仍然不完整。在这项研究中，属于不同功能组的四种树种的氮吸收效率（NRE），即Alnus nepalensis（非豆科植物固氮和落叶），Lithocarpus dealbatus（阔叶和常绿），松树（针叶和常绿）和木荷（矮叶半常绿）被研究。在最大叶片落下前，NRE在印度nu和Schima wallichii中最大，并在随后的几个月中下降。然而，在NRE石栎一年展现在所有月份相同的值。在松树，NRE最低，并且持续六个月。叶片和NRE中的氮含量在不同物种之间以及整个月中都有很大差异。属于某些功能组的树木在一年中不同月份的NRE值没有差异，这是因为可以采用其他方法来获取氮，或者自然界中的半/常绿植物可以应对其养分流失。