Finnish Environment Institute (SYKE), PO Box 140, FI-00251 Helsinki, Finland.
Forest Monitoring Laboratory, Aleksandras Stulginskis University, Studentu 13, Kaunas distr. LT-53362, Lithuania.
Sci Total Environ. 2018 Jun 1;625:1129-1145. doi: 10.1016/j.scitotenv.2017.12.245. Epub 2018 Jan 12.
The international Long-Term Ecological Research Network (ILTER) encompasses hundreds of long-term research/monitoring sites located in a wide array of ecosystems that can help us understand environmental change across the globe. We evaluated long-term trends (1990-2015) for bulk deposition, throughfall and runoff water chemistry and fluxes, and climatic variables in 25 forested catchments in Europe belonging to the UNECE International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). Many of the IM sites form part of the monitoring infrastructures of this larger ILTER network. Trends were evaluated for monthly concentrations of non-marine (anthropogenic fraction, denoted as x) sulphate (xSO) and base cations x(Ca+Mg), hydrogen ion (H), inorganic N (NO and NH) and ANC (Acid Neutralising Capacity) and their respective fluxes into and out of the catchments and for monthly precipitation, runoff and air temperature. A significant decrease of xSO deposition resulted in decreases in concentrations and fluxes of xSO in runoff, being significant at 90% and 60% of the sites, respectively. Bulk deposition of NO and NH decreased significantly at 60-80% (concentrations) and 40-60% (fluxes) of the sites. Concentrations and fluxes of NO in runoff decreased at 73% and 63% of the sites, respectively, and NO concentrations decreased significantly at 50% of the sites. Thus, the LTER/ICP IM network confirms the positive effects of the emission reductions in Europe. Air temperature increased significantly at 61% of the sites, while trends for precipitation and runoff were rarely significant. The site-specific variation of xSO concentrations in runoff was most strongly explained by deposition. Climatic variables and deposition explained the variation of inorganic N concentrations in runoff at single sites poorly, and as yet there are no clear signs of a consistent deposition-driven or climate-driven increase in inorganic N exports in the catchments.
国际长期生态研究网络（ILTER）包含数百个位于各种生态系统中的长期研究/监测站点，这些站点可以帮助我们了解全球范围内的环境变化。我们评估了欧洲 25 个森林流域内属于联合国欧洲经济委员会（UNECE）国际综合监测空气污染对生态系统影响合作方案（ICP IM）的长期趋势（1990-2015 年），这些长期趋势包括：大气沉降、穿透雨和地表径流的水质和通量以及气候变量。许多 ICP IM 站点是更大的 ILTER 网络监测基础设施的一部分。我们评估了非海洋（人为部分，记为 x）硫酸盐（xSO）和基础阳离子 x（Ca+Mg）、氢离子（H）、无机 N（NO 和 NH）和 ANC（酸中和能力）的月浓度以及它们各自进入和流出流域的通量，还评估了每月的降水量、径流量和空气温度。大气沉降中 xSO 的显著减少导致了径流水体中 xSO 浓度和通量的下降，在 90%和 60%的站点上分别具有显著意义。NO 和 NH 的大气沉降浓度在 60-80%（浓度）和 40-60%（通量）的站点上显著下降。NO 在径流水体中的浓度和通量分别在 73%和 63%的站点上下降，NO 浓度在 50%的站点上显著下降。因此，LTER/ICP IM 网络证实了欧洲减排的积极影响。61%的站点的空气温度显著上升，而降水和径流量的趋势很少具有显著意义。径流水体中 xSO 浓度的站点特异性变化主要受沉降的影响。气候变量和沉降对单个站点的无机 N 浓度变化的解释程度较差，目前还没有明确的迹象表明流域中无机 N 输出有一致的沉积驱动或气候驱动的增加。
