Data: Natural nanoparticles and colloids in forested streams across Europe: seasonal patterns and impact of soil groups

Data and R codes for Manuscript: The element loss from forested ecosystems is largely reflected by the so-called dissolved phase (< 450 nm) in stream waters. However, natural colloids (1 nm – 1 µm), including natural nanoparticles (NNP, 1-100 nm), constitute a major but so far, largely unexplored part of this dissolved phase. We hypothesized that i) there is a systematic seasonal variation in colloidal concentrations across European catchments, and, that ii) the colloidal concentrations are mainly controlled by site conditions, i.e., prevalent reference soil groups. To test these hypotheses, the base flow of seven stream waters was sampled from a transect across Europe from Northern Finland to Portugal at monthly intervals for one year. Three colloidal size fractions (1-20 nm, >20-60 nm and >60 nm) were identified using Field Flow Fractionation coupled with inductively coupled plasma mass spectrometry and an organic carbon detector for the size-resolved detection of Al, Si, P, Ca, Mg, Mn, Fe, Zn and organic C. Colloids accounted for up to 90-100% of total element concentrations, emphasizing the importance of colloids for element cycling. Element concentrations showed seasonal patterns in stream waters. These patterns, however, differed between the catchments with distinct soil groups: the catchments with dystrophic terrestrial soils exhibited peak flows in colloidal element concentrations during spring, while those with eutrophic terrestrial soils did during summer. By contrast, catchments with semiterrestrial soils showed season-unrelated, single peaks of high element export. Peak concentrations were also influenced by the climatic regime, which in turn impacted colloid abundance.本研究论文配套数据集与R代码： 森林生态系统的元素流失，在很大程度上可通过溪流水体中所谓的<450 nm溶解相（dissolved phase）得以反映。然而，天然胶体（natural colloids，粒径范围1 nm~1 µm）——包含天然纳米颗粒（natural nanoparticles, NNP，1~100 nm）——是该溶解相的重要组成部分，但迄今为止该部分的研究仍未得到充分探索。本研究提出两项假设：其一，欧洲各流域的胶体浓度存在系统性季节变化；其二，胶体浓度主要受立地条件调控，即受区域优势参考土壤类群的影响。 为验证上述两项假设，研究团队在一年内按月采样，从芬兰北部至葡萄牙的欧洲样带中采集了7处溪流水体的基流样本。研究采用场流分级法（Field Flow Fractionation, FFF）结合电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry, ICP-MS）与有机碳检测器，对3种胶体粒径组分（1~20 nm、>20~60 nm及>60 nm）进行分离，并实现了Al、Si、P、Ca、Mg、Mn、Fe、Zn及有机碳的粒径分辨检测。 胶体可占总元素浓度的90%~100%，凸显了胶体在元素循环中的关键作用。溪流水体的元素浓度呈现季节分布特征，但不同土壤类群对应的流域其季节模式存在显著差异：贫营养陆地土壤流域的胶体态元素浓度峰值出现在春季，而富营养陆地土壤流域的峰值则出现在夏季。相较而言，半陆生土壤流域的高元素输出峰值与季节无关，仅出现单次峰值。浓度峰值还受气候状况的调控，而气候状况反过来又会影响胶体丰度。