Carbon and nitrogen accumulation rates in ombrotrophic peatlands of central and northern Alberta, Canada, during the last millennium

摘要: Northern peatlands sequester carbon (C) and nitrogen (N) over millennia, at variable rates that depend on climate, environmental variables anthropogenic activity. The ombrotrophic of central northern Alberta (Canada) have developed under climate conditions during the last hundreds to thousands years, while in course twentieth century, some regions were also likely subjected disturbance. We aimed quantify peat C N accumulation for millennium from seven estimate relative influence disturbance dynamics. Peatlands accumulated an average rate 25.3 g C m−2 year−1 millennium. Overall, was a major factor as, average, highest apparent found around 1100 CE, warmer Medieval Climate Anomaly, with lowest Little Ice Age, 1750 CE. Local factors, such as disturbance, played role sequestration site scale. 0.55 g N m−2 year−1, high inter- intra-site variability. In general, mirrored patterns deposited pre-1850 However, higher observed after 1850 averaging 0.94 g N m−2 year−1, not correlated accumulation. Moreover, historically strongly accumulating sites may become less efficient sequestering C, vice versa. All showed marked decrease δ15N when comparing pre- post-1850 timeframes, consistent increasing post-1850 N additions atmospheric source, biological fixation. driving