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植物种内性状的变异对个体适合度和草食动物的觅食有重要影响.对于植物来说,在空间维度上的性状变异已经得到了很好的证明.然而,对性状变异的时间维度仍知之甚少,但其可能受生长度日、温度和降水季节差异的影响.本研究的目的 是量化4种常见的北方植物物种性状的种内时间变异及其变异的驱动因素.我们对4种常见树种的叶片进行了为期两年的元素和化学计量性状采样(％C,％N,％P,C∶N,C∶P,N∶P).本研究分两个步骤进行,首先将广义线性模型(GzLM,n=24)与我们研究的物种的元素和化学计量性状拟合,以测试它们是否随年份而变化.当我们获得时间变异性的证据时,我们拟合第二组GzLMs(n=8),将温度、生产力和湿度作为解释变量.研究结果显示,除了两个例外,4种北方植物的大部分元素和化学计量性状都没有时间变异性.年份是所有4种植物的碳百分比(R2=0.47-0.67)以及香脂冷杉(Abies balsamea)中多种元素和化学计量性状(5/8,R2=0.29-0.67)的重要预测因子.因此,碳百分比的变化与年际差异有关,而与限制北方森林养分的氮和磷关系更大.这些研究结果还表明,由于生活史的差异,针叶树的化学计量比落叶植物的化学计量的年际差异更大.生长度日是第二轮模型中最频繁出现的变量(8/8次,R2=0.21-0.41),表明温度是这些性状时间变异的重要驱动因素.“,”Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging.For plants,trait variability across spatial dimensions is well documented.However,temporal dimensions of trait variability are less well known,and may be influenced by seasonal differences in growing degree days(GDD),temperature and precipitation.Here,we aim to quantify intraspecific temporal variation in traits and the underlying drivers for four commonly occurring boreal plant species.Methods We sampled the elemental and stoichiometric traits (％C,％N,％P,C∶N,C∶P,N∶P) of four common browse species\' foliage across 2 years.Using a two-step approach,we first fitted generalized linear models(GzLM,n =24) to the species\' elemental and stoichiometric traits,and tested if they varied across years.When we observed evidence for temporal variability,we fitted a second set of GzLMs (n =8) with temperature,productivity and moisture as explanatory variables.Important Findings We found no evidence of temporal variation for most of the elemental and stoichiometric traits of our four boreal plants,with two exceptions.Year was an important predictor for percent carbon across all four species (R2 =0.47-0.67) and for multiple elemental and stoichiometric traits in balsam fir (5/8,R2 =0.29-0.67).Thus,variation in percent carbon was related to interannual differences,more so than nitrogen and phosphorus,which are limiting nutrients in the boreal forest.These results also indicate that year may explain more variation in conifers\' stoichiometry than for deciduous plants due to life history differences.GDD was the most frequently occurring variable in the second round of models (8/8 times,R2 =0.21-0.41),suggesting that temperature is an important driver of temporal variation in these traits.