Siberian environmental change: Synthesis of recent studies and opportunities for networking

A recent multidisciplinary compilation of studies on changes in the Siberian environment details how climate is changing faster than most places on Earth with exceptional warming in the north and increased aridity in the south. Impacts of these changes are rapid permafrost thaw and melt of glaciers, increased flooding, extreme weather events leading to sudden changes in biodiversity, increased forest fires, more insect pest outbreaks, and increased emissions of CO₂ and methane. These trends interact with sociological changes leading to land-use change, globalisation of diets, impaired health of Arctic Peoples, and challenges for transport. Local mitigation and adaptation measures are likely to be limited by a range of public perceptions of climate change that vary according to personal background. However, Siberia has the possibility through land surface feedbacks to amplify or suppress climate change impacts at potentially global levels. Based on the diverse studies presented in this Ambio Special Issue, we suggest ways forward for more sustainable environmental research and management.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01626-7.     

葫芦岛地区汞在土壤-植物-昆虫系统中的生物地球化学迁移

通过研究葫芦岛地区土壤、植物及不同食性昆虫的汞含量,探讨了汞的生物地球化学迁移．结果表明,汞污染使植物汞含量增加,生物吸收程度大大提高．植物及昆虫灰分基汞含量均高于汞在地壳的克拉克值．不同食性昆虫灰分基汞含量存在显著性差异,表现出肉食性〉杂食性〉植食性的规律．汞能够沿着食物链由植食性昆虫向肉食性昆虫进行传递,土壤-植物、植物-植食性昆虫、植食性昆虫．肉食性昆虫系统中,汞的富集倍数分别为（1-n）×10^-1、（1-n）×10、（1-n）的水平,土壤汞污染可以通过食物链传递造成昆虫体内汞的富集．     

Hydrobiogeochemical Controls on Riparian Nutrient and Greenhouse Gas Dynamics: 10 Years Post‐Restoration

Little is known about the impact of agricultural legacy on subsurface biogeochemical processes in the years following restoration of riparian wetlands (WLs). More knowledge is also needed on the relative importance of seasons, precipitation events, and inputs of water and nutrients driving nitrogen (N), phosphorus (P), sulfur (S), and greenhouse gas (GHG) (N₂O, CO₂, CH₄) dynamics in these systems. This investigation of a riparian zone comprising a restored WL area and a nonrestored well‐drained alluvium (AL) area in the United States Midwest revealed that despite successful hydrological restoration a decade earlier, biogeochemical conditions in the WL area remained less anoxic than in natural WLs, and not significantly different from those in the AL area. No significant differences in N, P, S, and C compound concentrations or fluxes were observed between the AL and WL areas. Over the duration of the study, nitrate (NO₃^?) and soluble reactive phosphorus appeared to be primarily driven by hillslope contributions. Ammonium (NH₄⁺), sulfate (SO₄^2?), and CO₂ responded strongly to seasonal changes in biogeochemical conditions in the riparian zone, while N₂O and CH₄ fluxes were most influenced by large rewetting events. Overall, our results challenge overly simplistic assumptions derived from direct interpretation of redox thermodynamics, and show complex patterns of solutes and GHGs at the riparian zone scale.