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Snow is a crucial part in the lives of Sámi reindeer herders, and changes in snow conditions can affect their well-being in multiple ways. However, meanings and emotions associated with snow are rarely considered in research on reindeer herding and climate change. Based on thematic interviews with reindeer herders in two reindeer herding co-operatives in the Sámi Homeland in Finland, we examined the roles and meanings of snow for Sámi reindeer herders and impacts of the extreme winter events of recent years on their well-being. In addition, based on a literature survey, we considered the role of reindeer herders’ snow knowledge in climate change research related to the Sámi area in Finland, Sweden, and Norway. Our results show that snow plays multiple roles in the lives of reindeer herders. The extreme snow conditions of recent years have had a significant negative impact on reindeer herder well-being, and at the same time, snow is connected to happiness, sense of place, and cultural continuity. The embeddedness of snow with different kinds of cultural and intrinsic meanings should receive more attention in research on the impacts of climate change on the lives of Sámi and other Arctic peoples. In the literature we analyzed, the snow knowledge of Sámi reindeer herders was constructed in multiple ways. This practical knowledge system informing, as it does, daily activities and assessments of the future, is not only crucial for reindeer herders themselves, but also for society at large, as it can enhance education and bring important insights into climate change research and adaptation. 

Summary Plant phenology, the timing of recurrent biological events, shows key and complex response to climate warming, with consequences for ecosystem functions and services. A key challenge for predicting plant phenology under future climates is to determine whether the phenological changes will persist with more intensive and long‐term warming.Here, we conducted a meta‐analysis of 103 experimental warming studies around the globe to investigate the responses of four phenophases – leaf‐out, first flowering, last flowering, and leaf coloring.We showed that warming advanced leaf‐out and flowering but delayed leaf coloring across herbaceous and woody plants. As the magnitude of warming increased, the response of most plant phenophases gradually leveled off for herbaceous plants, while phenology responded in proportion to warming in woody plants. We also found that the experimental effects of warming on plant phenology diminished over time across all phenophases. Specifically, the rate of changes in first flowering for herbaceous species, as well as leaf‐out and leaf coloring for woody species, decreased as the experimental duration extended.Together, these results suggest that the real‐world impact of global warming on plant phenology will diminish over time as temperatures continue to increase. 

Abstract Tundra shrubs reflect climate sensitivities in their growth-ring widths, yet tissue-specific shrub chronologies are poorly studied. Further, the relative importance of regional climate patterns that exert mesoscale precipitation and temperature influences on tundra shrub growth has been explored in only a few Arctic locations. Here, we investigateBetula nanagrowth-ring chronologies from adjacent dry heath and moist tussock tundra habitats in arctic Alaska in relation to local and regional climate. Mean shrub and five tissue-specific ring width chronologies were analyzed using serial sectioning of above- and below-ground shrub organs, resulting in 30 shrubs per site with 161 and 104 cross sections from dry and moist tundra, respectively.Betula nanagrowth-ring widths in both habitats were primarily related to June air temperature (1989–2014). The strongest relationships with air temperature were found for ‘Branch2’ chronologies (dry site:r = 0.78, June 16, DOY = 167; moist site:r = 0.75, June 9, DOY = 160). Additionally, below-ground chronologies (‘Root’ and ‘Root2’) from the moist site were positively correlated with daily mean air temperatures in the previous late-June (‘Root2’ chronology:r = 0.57, pDOY = 173). Most tissue-specific chronologies exhibited the strongest correlations with daily mean air temperature during the period between 8 and 20 June. Structural equation modeling indicated that shrub growth is indirectly linked to regional Arctic and Pacific Decadal Oscillation (AO and PDO) climate indices through their relation to summer sea ice extent and air temperature. Strong dependence ofBetula nanagrowth on early growing season temperature indicates a highly coordinated allocation of resources to tissue growth, which might increase its competitive advantage over other shrub species under a rapidly changing Arctic climate. 

Vertebrate herbivore excrement is thought to influence nutrient cycling, plant nutrition, and growth; however, its importance is rarely isolated from other aspects of herbivory, such as trampling and leaf removal, leaving questions about the extent to which herbivore effects are due to feces. We hypothesized that as a source of additional nutrients, feces would directly increase soil N concentrations and N2O emission, alleviate plant, and microbial nutrient limitations, resulting in increased plant growth and foliar quality, and increase CH4 emissions. We tested these hypotheses using a field experiment in coastal western Alaska,USA, where we manipulated goose feces such that naturally grazed areas received three treatments:feces removal, ambient amounts of feces, or double ambient amounts of feces. Doubling feces marginally increased NH4 +-N in soil water, whereas both doubled feces and feces removal significantly increased NO3--N; N2O flux was also higher in removal plots. Feces removal marginally reduced root biomass and significantly reduced productivity (that is, GPP) in the second year, measured as greater CO2 emissions. Doubling feces marginally increased foliar chemical quality by increasing %N and decreasing C:N. Treatments did not influence CH4 flux. In short, feces removal created sites poorer in nutrients, with reduced root growth, graminoid nutrient uptake, and productivity. While goose feces alone did not create dramatic changes in nutrient cycling in western Alaska, they do appear to be an important source of nutrients for grazed areas and to contribute to greenhouse gas exchange as their removal increased emissions of CO2 and N2O to the atmosphere.