An iron-reduction-mediated cascade mechanism increases the risk of carbon loss from mineral-rich peatlands

Forest-peat fires are notable for their difficulty in estimating carbon losses. Combined carbon losses from tree biomass and peat soil were estimated at an 8 ha forest-peat fire in the Moscow region after catastrophic fires in 2010. The loss of tree biomass carbon was assessed by reconstructing forest stand structure using the classification of pre-fire high-resolution satellite imagery and after-fire ground survey of the same forest classes in adjacent areas. Soil carbon loss was assessed by using the root collars of stumps to reconstruct the pre-fire soil surface and interpolating the peat characteristics of adjacent non-burned areas. The mean (median) depth of peat losses across the burned area was 15 ± 8 (14) cm, varying from 13 ± 5 (11) to 20 ± 9 (19). Loss of soil carbon was 9.22 ± 3.75–11.0 ± 4.96 (mean) and 8.0–11.0 kg m−2 (median); values exceeding 100 tC ha−1 have also been found in other studies. The estimated soil carbon loss for the entire burned area, 98 (mean) and 92 (median) tC ha−1, significantly exceeds the carbon loss from live (tree) biomass, which averaged 58.8 tC ha−1. The loss of carbon in the forest-peat fire thus equals the release of nearly 400 (soil) and, including the biomass, almost 650 tCO2 ha−1 into the atmosphere, which illustrates the underestimated impact of boreal forest-peat fires on atmospheric gas concentrations and climate.

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Effects and mechanisms of modified biochars on microbial iron reduction of Geobacter sulfurreducens

Chemosphere ◽

10.1016/j.chemosphere.2021.130983 ◽

2021 ◽

pp. 130983

Author(s):

Yue Lu ◽

Yingju Hu ◽

Lin Tang ◽

Qingqing Xie ◽

Qian Liu ◽

...

Keyword(s):

Iron Reduction ◽

Geobacter Sulfurreducens ◽

Microbial Iron Reduction

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Hemochromatosis Mutations, Brain Iron Imaging, and Dementia in the UK Biobank Cohort

Journal of Alzheimer s Disease ◽

10.3233/jad-201080 ◽

2021 ◽

pp. 1-9

Author(s):

Janice L. Atkins ◽

Luke C. Pilling ◽

Christine J. Heales ◽

Sharon Savage ◽

Chia-Ling Kuo ◽

...

Keyword(s):

Iron Reduction ◽

Brain Mri ◽

European Ancestry ◽

Uk Biobank ◽

Brain Iron ◽

Mri Features ◽

Incident Dementia ◽

Hfe Mutations ◽

The Uk

Background: Brain iron deposition occurs in dementia. In European ancestry populations, the HFE p.C282Y variant can cause iron overload and hemochromatosis, mostly in homozygous males. Objective: To estimated p.C282Y associations with brain MRI features plus incident dementia diagnoses during follow-up in a large community cohort. Methods: UK Biobank participants with follow-up hospitalization records (mean 10.5 years). MRI in 206 p.C282Y homozygotes versus 23,349 without variants, including T2 * measures (lower values indicating more iron). Results: European ancestry participants included 2,890 p.C282Y homozygotes. Male p.C282Y homozygotes had lower T2 * measures in areas including the putamen, thalamus, and hippocampus, compared to no HFE mutations. Incident dementia was more common in p.C282Y homozygous men (Hazard Ratio HR = 1.83; 95% CI 1.23 to 2.72, p = 0.003), as was delirium. There were no associations in homozygote women or in heterozygotes. Conclusion: Studies are needed of whether early iron reduction prevents or slows related brain pathologies in male HFE p.C282Y homozygotes.

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