The leaf economics spectrum (LES) is based on a suite of leaf traits related to plant functioning and ranges from resource‐conservative to resource‐acquisitive strategies. However, the relationships with root traits, and the associated belowground plant functioning such as N uptake, including nitrate (NO₃⁻) and ammonium (NH₄⁺), is still poorly known. Additionally, environmental variations occurring both in time and in space could uncouple LES from root traits. We explored, in subalpine grasslands, the relationships between leaf and root morphological traits for three dominant perennial grass species, and to what extent they contribute to the whole‐plant economics spectrum. We also investigated the link between this spectrum and NO₃⁻ and NH₄⁺ uptake rates, as well as the variations of uptake across four grasslands differing by the land‐use history at peak biomass and in autumn. Although poorly correlated with leaf traits, root traits contributed to an economic spectrum at the whole plant level. Higher NH₄⁺ and NO₃⁻ uptake abilities were associated with the resource‐acquisitive strategy. Nonetheless, NH₄⁺ and NO₃⁻‐uptake within species varied between land‐uses and with sampling time, suggesting that LES and plant traits are good, but still incomplete, descriptors of plant functioning. Although the NH₄⁺:NO₃⁻ uptake ratio was different between plant species in our study, they all showed a preference for NH₄⁺, and particularly the most conservative species. Soil environmental variations between grasslands and sampling times may also drive to some extent the NH₄⁺ and NO₃⁻ uptake ability of species. Our results support the current efforts to build a more general framework including above‐ and below‐ground processes when studying plant community functioning.

中文翻译：

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亚高山植物对NH4 +和NO3-的吸收能力及其功能性状的资源利用策略研究

叶经济学谱（LES）基于与植物功能相关的一系列叶性状，范围从资源保守到资源获取策略。然而，随着根性状的关系，及相关的地下植物发挥功能，如N摄取，包括硝酸盐（NO ₃ ^- ）和铵（NH ₄ ⁺），仍然知之甚少。此外，在时间和空间上发生的环境变化都可能使LES与根系特性脱钩。我们在亚高山草原上探索了三种主要多年生草种的叶片与根系形态特征之间的关系，以及它们在多大程度上对整个植物的经济谱做出了贡献。我们还调查了这个频谱和NO之间的联系₃ ^-NH ₄ ^+的吸收率，以及四个草地的吸收变化因生物量峰值和秋季的土地利用历史而异。尽管与叶片性状的相关性较弱，但根部性状在整个植物水平上都有助于经济。较高的NH ₄ ⁺和NO ₃ ^-的吸收能力是与资源聚财战略有关。尽管如此，NH ₄ ⁺和NO ₃ ^-土地用途之间，并与采样时间，表明LES和植物性状良好变化物种内-uptake，但是仍然不完全，植物运作描述符。虽然NH ₄ ⁺：NO ₃ ^-在我们的研究中，不同植物物种的吸收率不同，它们都显示出对NH ₄ ⁺的偏爱，尤其是最保守的物种。草原和取样时间之间的土壤环境的变化也可以驱动在一定程度上NH ₄ ⁺和NO ₃ ^-物种的吸收能力。我们的结果支持当前在研究植物群落功能时建立更通用的框架（包括地上和地下过程）的努力。