College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China; The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling, 712100 Shaanxi, China.
College of Grassland Agriculture, Northwest A&F University, Yangling, 712100 Shaanxi, China.
Sci Total Environ. 2021 Sep 20;788:147807. doi: 10.1016/j.scitotenv.2021.147807. Epub 2021 May 17.
Leaf nutrient resorption is one of the important mechanisms for nutrient conservation in plants. Element stoichiometry is crucial to characterizing nutrient limitations and terrestrial ecosystem function. Here, we use nitrogen (N) and phosphorus (P) resorption efficiencies (NRE and PRE) and their stoichiometry to evaluate the response patterns of leaf nutrient resorption efficiency (NuRE) to plant functional groups, species traits, climate, and soil nutrients on the global scale. In light of the findings from the global data set of published literature on N and P resorption by woody plants, we revisit the commonly held views that: The strong N fixation ability of N-fixers weakened the NRE, which was consistent with the general views. The NuRE was linearly negatively correlated with plant growth rate. The higher NuRE of evergreen species than deciduous plants revealed how leaf life span constrains nutrient conservation. From the perspective of NRE, PRE and their ratios, woody plants were limited by P in the tropical zone and the limiting nutrient gradually transformed into N in the temperate zone (23.43-66.57°). The NuRE of woody plants in the frigid zone was the largest than that of others implied that low temperature may limit the nutrient absorption by plant roots, thereby enhancing the retranslocation of nutrients by senesced leaves. Furthermore, Akaike weights analysis found that mean annual precipitation (MAP) and temperature (MAT), N-fixers, soil nutrients, and leaf life span have significant effects on nutrient resorption patterns, sequentially. Overall, these results showed that the plasticity of plant nutrient resorption patterns was strongly sensitive to plant functional groups and soil nutrients, but the regularity of NuRE on a global scale was controlled by temperature and precipitation. And the resorption stoichiometry pattern better interprets plant nutrient limitation and the synergy effect of N and P in plant and soil on multiple scales.
叶片养分再吸收是植物养分保存的重要机制之一。元素化学计量对于刻画养分限制和陆地生态系统功能至关重要。在这里，我们利用氮（N）和磷（P）再吸收效率（NRE 和 PRE）及其化学计量来评估叶片养分再吸收效率（NuRE）对植物功能群、物种特性、气候和土壤养分的全球响应模式。根据来自木本植物氮和磷再吸收的已发表文献的全球数据集的结果，我们重新审视了以下普遍观点：固氮生物固氮能力的增强削弱了 NRE，这与普遍观点一致。NuRE 与植物生长率呈线性负相关。与落叶植物相比，常绿物种具有更高的 NuRE，这揭示了叶片寿命如何限制养分保存。从 NRE、PRE 及其比值的角度来看，木本植物在热带地区受到 P 的限制，而在温带地区（23.43-66.57°）限制养分逐渐转变为 N。寒带木本植物的 NuRE 最大，这意味着低温可能限制植物根系对养分的吸收，从而增强衰老叶片中养分的再转移。此外，Akaike 权重分析发现，年平均降水量（MAP）和温度（MAT）、固氮生物、土壤养分和叶片寿命对养分再吸收模式有显著影响，依次为。总的来说，这些结果表明，植物养分再吸收模式的可塑性对植物功能群和土壤养分具有很强的敏感性，但 NuRE 在全球范围内的规律性受温度和降水控制。并且，再吸收化学计量模式更好地解释了植物养分限制以及植物和土壤中 N 和 P 的协同作用在多个尺度上的表现。
