Abstract In non-desert areas primary biological aerosol particles, including pollen, are an important source of phosphorus (P). During the flowering season large quantities of pollen from wind pollinated trees, are observed in boreal and temperate lakes and forest, which contain high P concentrations. However, there are different estimations for the contribution of pollen to the atmospheric P cycle, and there is no accepted method for the identification of phosphate from pollen origin. In this study we measured the P concentrations in pollen from various locations. In addition, the oxygen stable isotopes ratio in phosphate (δ18OP) was measured for the first time for both the bioavailable pool (P extractable by anion-exchange resin), and for the HCl-extractable pool. The resin and HCl-extractable δ18OP values were on average (±SE) 25.6 ± 3.4‰, and 25.8 ± 2.9‰, which are distinctively higher than mineral dust δ18OP values (average 22.1 ± 0.7‰). Pollen unique isotopic signature in phosphate can be used as a tool to identify P in aerosols from pollen origin, and hence to better understand the atmospheric P cycle. The high P concentrations found in this study (average (±SE) resin-P and HCl-P values were 0.67 ± 0.10 and 0.75 ± 0.9 mg P g−1), confirm that pollen is important to the atmospheric P budget, and can help to solve the uncertainties regarding its role in the global P cycle.

中文翻译：

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空气中树木花粉中大气磷酸盐的同位素特征

摘要 在非沙漠地区，包括花粉在内的初级生物气溶胶颗粒是磷（P）的重要来源。在开花季节，在寒带和温带湖泊和森林中观察到大量来自风授粉树的花粉，它们含有高浓度的磷。然而，关于花粉对大气 P 循环的贡献有不同的估计，并且没有公认的方法来鉴定来自花粉的磷酸盐。在这项研究中，我们测量了来自不同地点的花粉中的 P 浓度。此外，首次测量了生物可利用池（可通过阴离子交换树脂提取的磷）和 HCl 可提取池的磷酸盐（δ18OP）中的氧稳定同位素比率。树脂和 HCl 可萃取的 δ18OP 值平均 (±SE) 25.6 ± 3.4‰，和 25.8±2.9‰，明显高于矿物粉尘 δ18OP 值（平均 22.1±0.7‰）。磷酸盐中花粉独特的同位素特征可用作识别来自花粉的气溶胶中的 P 的工具，从而更好地了解大气 P 循环。本研究中发现的高 P 浓度（平均 (±SE) 树脂-P 和 HCl-P 值为 0.67 ± 0.10 和 0.75 ± 0.9 mg P g-1），证实花粉对大气 P 收支很重要，并且可以有助于解决其在全球磷循环中作用的不确定性。