National Pollen and Aerobiological Research Unit, School of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, United Kingdom.
National Pollen and Aerobiological Research Unit, School of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, United Kingdom.
Sci Total Environ. 2019 May 1;663:527-536. doi: 10.1016/j.scitotenv.2019.01.212. Epub 2019 Jan 18.
Oak pollen seasons are relatively unexplored in large parts of Europe despite producing allergens and being a common tree in both continental and northern parts. Many studies are concentrated only on the Iberian Peninsula. In this study, the seasonal pattern of oak pollen in Europe was analysed using 10 observation sites, ranging from Spain to Sweden. The magnitude of peaks and annual pollen integral together with season-length were studied and substantially higher pollen levels and longer seasons were found in Spain. Two northern sites in Denmark and Sweden showed high oak pollen peaks together with two sites in Spain and United Kingdom. The study also tested four common definitions of season start and applied a generalized phenological model for computing the start of the pollen season. The most accurate definition for a European-wide description of the observed oak pollen start was when the cumulative daily average pollen count reached 50 grains per cubic meter. For the modelling of the start a thermal time method based on Growing Degree Day (GDD) was implemented, utilizing daily temperatures and a generalized approach to identify model parameters applicable to all included sites. GDD values varied between sites and generally followed a decreasing gradient from south to north, with some exceptions. Modelled onsets with base temperatures below 7 °C matched well with observed onsets and 76% of the predictions differed ≤4 days compared to observed onsets when using a base temperature of 2 °C. Base temperatures above 7 °C frequently predicted onsets differing >1 week from the observed. This general approach can be extended to a larger area where pollen observations are non-existent. The presented work will increase the understanding of oak pollen variation in Europe and provide knowledge of its phenology, which is a critical aspect both for modelling purposes on large-scale and assessing the human exposure to oak allergens.
尽管栎属花粉是过敏原，且在欧洲大陆和北部地区都很常见，但在很大一部分地区，栎属花粉季节仍相对缺乏研究。许多研究仅集中在伊比利亚半岛。在这项研究中，使用了 10 个观测点（从西班牙到瑞典）分析了欧洲栎属花粉的季节性模式。研究了峰值幅度和年花粉积分以及季节长度，发现西班牙的花粉水平和季节长度都显著更高。丹麦和瑞典的两个北部站点以及西班牙和英国的两个站点显示出高栎属花粉峰值。该研究还测试了季节开始的四个常见定义，并应用了广义物候模型来计算花粉季节的开始。对于观察到的栎属花粉开始的全欧洲描述，最准确的定义是当累积日平均花粉计数达到每立方米 50 粒时。为了对开始进行建模，采用了基于有效积温（GDD）的热量时间方法，利用日温度和广义方法来确定适用于所有包含站点的模型参数。GDD 值在站点之间有所不同，通常从南到北呈递减梯度，但也有一些例外。以低于 7°C 的基础温度进行的模拟开始与观察到的开始非常吻合，当使用 2°C 的基础温度时，76%的预测与观察到的开始相差≤4 天，而当使用 7°C 以上的基础温度时，预测开始的时间经常相差超过 1 周。这种通用方法可以扩展到花粉观测不存在的更大区域。所呈现的工作将提高对欧洲栎属花粉变化的认识，并提供其物候学的知识，这对于大规模建模和评估人类对栎属过敏原的暴露都是至关重要的。
