School of Forestry & Landscape Architecture, Anhui Agricultural University, Hefei 230036, Anhui, China.
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
Sci Total Environ. 2023 May 1;871:162075. doi: 10.1016/j.scitotenv.2023.162075. Epub 2023 Feb 8.
Nutrient resorption is an important mechanism for nutrient conservation and can maintain ecosystem stoichiometry. Here, we examined the global-scale variation of nitrogen resorption efficiency (NRE) and phosphorus resorption efficiency (PRE) by analyzing observations from 218 published papers. We used Pagel's λ to test the phylogenetic limitation on NRE and PRE and applied the random forest model to assess biotic and abiotic drivers, which included climate, soil, species characteristics, and topographical factors, and predicted the global NRE and PRE distributions. We found that NRE and PRE had oppositing trends among climatic zones, plant functional groups, and foliar nitrogen (N) to phosphorus (P) ratios. Nutrient resorption was higher in ectomycorrhizal trees than in arbuscular mycorrhizal trees. Moreover, foliar NRE and PRE were not linked to phylogeny. On average, the random forest overall explained 38 % (21 %-55 %) variation in NRE and 36 % (16 %-55 %) variation in PRE. Both NRE and PRE varied greatly with climate and soil organic carbon (SOC). The spatial variation of NRE and PRE was coupled to N-limitation and P-limitation, respectively. Our evaluation of the factors that influenced NRE and PRE and their global distributions, and our novel approach for evaluating plant utilization of nutrients, advances our understanding of the relative stability of ecosystem randomness in forest ecosystems and the global forest nutrient cycle.
养分再吸收是一种重要的养分保存机制，可维持生态系统化学计量平衡。在这里，我们通过分析 218 篇已发表论文中的观测结果，研究了全球范围内氮再吸收效率（NRE）和磷再吸收效率（PRE）的变化。我们使用 Pagel 的 λ 检验了 NRE 和 PRE 的系统发育限制，并应用随机森林模型评估了生物和非生物驱动因素，包括气候、土壤、物种特征和地形因素，并预测了全球 NRE 和 PRE 的分布。我们发现，NRE 和 PRE 在气候带、植物功能群和叶片氮（N）与磷（P）比值方面表现出相反的趋势。外生菌根树的养分再吸收高于丛枝菌根树。此外，叶片 NRE 和 PRE 与系统发育无关。平均而言，随机森林总体解释了 38%（21%-55%）的 NRE 变化和 36%（16%-55%）的 PRE 变化。NRE 和 PRE 都随气候和土壤有机碳（SOC）而有很大变化。NRE 和 PRE 的空间变化分别与氮限制和磷限制有关。我们对影响 NRE 和 PRE 的因素及其全球分布的评估，以及我们对植物利用养分的新评估方法，增进了我们对森林生态系统中生态系统随机性相对稳定性和全球森林养分循环的理解。
