Background

This paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey.

Results

Correlations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5 km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75–100 km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of < 40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (= above-average) or low (= below-average) correlation coefficients.

Conclusions

LDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites.

中文翻译：

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模拟 2010 年欧洲苔藓中重金属浓度与大气沉降之间相关性的空间模式。

背景

本文旨在研究覆盖欧洲的生态土地类别中苔藓中九种重金属的浓度与大气沉降之间的相关性。此外，还检查了统计关系在多大程度上受到苔藓采样点周围土地利用的影响。根据 2010/2011 年在整个欧洲收集的苔藓数据和由两个化学传输模型（EMEP MSC-E、LOTOS-EUROS）模拟的大气总沉降数据，指定了苔藓中重金属浓度和模拟大气沉积之间的相关系数用于由欧洲生态土地类别 (ELCE) 定义为空间参考系统的空间子样本。然后使用线性判别分析（LDA）和逻辑回归（LR）来区分苔藓采样点，考虑到采样点周围城市、农业和林业用地的面积百分比，它们对相关强度的贡献。在 LR 验证 LDA 模型后，LDA 模型被用于将土地利用的空间信息转换为潜在相关级别的地图，适用于欧洲莫斯调查中的未来网络规划。

结果

发现苔藓中的重金属浓度和模拟的大气沉降之间的相关性对于元素和 ELCE 单位是特定的。采样点周围的土地利用主要影响相关性水平。检查的采样点周围的小半径（5 公里）与 Cd、Cu、Ni 和 Zn 更相关，而大半径（75-100 公里）内城市和农业用地的面积百分比与 As、Cr 更相关、Hg、Pb 和 V。对于 As、Cr、Cu、Hg、Pb 和 V，发现了错误率小于 40% 的大多数有效 LDA 模型模式。空间模式的土地利用相关预测将欧洲划分为调查区域揭示潜在的高（= 高于平均水平）或低（= 低于平均水平）的相关系数。

结论

考虑到苔藓采样点周围土地利用的影响，LDA 是一种合格的方法，用于识别和排序大气沉降与苔藓中相应重金属浓度之间相关性的边界条件以及相关制图。