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TitleHuman and climate global-scale imprint on sediment transfer during the Holocene
AuthorJenny, J -P; Koirala, S; Gregory-Eaves, I; Francus, P; Niemann, C; Ahrens, B; Brovkin, V; Baud, A; Ojala, A E K; Normandeau, AORCID logo; Zolitschka, B; Carvalhais, N
SourceProceedings of the National Academy of Sciences of the United States of America 2019 p. 1-5, Open
Access logo Open Access
Alt SeriesNatural Resources Canada, Contribution Series 20180346
PublisherNational Academy of Sciences
Mediapaper; on-line; digital
File formatpdf (Adobe® Reader®); html
ProvinceCanada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut; Canada
NTS1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long WENS-180.0000 180.0000 90.0000 -90.0000
Subjectsenvironmental geology; surficial geology/geomorphology; soils science; geochronology; paleontology; Nature and Environment; Holocene; climatology; climate effects; paleoclimates; lake sediment cores; soils; paleosols; erosion; watersheds; surface waters; lakes; sediment dispersal; sedimentation rates; radiometric dating; radiocarbon dating; pollen analyses; models; ecosystems; carbon; Climate change; Land cover; Environmental impact assessment; lacustrine sediments
Illustrationslocation maps; histograms; frequency distribution diagrams; tables; plots; time series
Released2019 10 28
AbstractAccelerated soil erosion has become a pervasive feature on landscapes around the world and is recognized to have substantial implications for land productivity, downstream water quality, and biogeochemical cycles. However, the scarcity of global syntheses that consider long-term processes has limited our understanding of the timing, the amplitude, and the extent of soil erosion over millennial time scales. As such, we lack the ability to make predictions about the responses of soil erosion to long-term climate and land cover changes. Here, we reconstruct sedimentation rates for 632 lakes based on chronologies constrained by 3,980 calibrated 14C ages to assess the relative changes in lake-watershed erosion rates over the last 12,000 y. Estimated soil erosion dynamics were then complemented with land cover reconstructions inferred from 43,669 pollen samples and with climate time series from the Max Planck Institute Earth System Model. Our results show that a significant portion of the Earth surface shifted to human-driven soil erosion rate already 4,000 y ago. In particular, inferred soil erosion rates increased in 35%of the watersheds, and most of these sites showed a decrease in the proportion of arboreal pollen, which would be expected with land clearance. Further analysis revealed that land cover change was the main driver of inferred soil erosion in 70% of all studied watersheds. This study suggests that soil erosion has been altering terrestrial and aquatic ecosystems for millennia, leading to carbon (C) losses that could have ultimately induced feedbacks on the climate system.
Summary(Plain Language Summary, not published)
We reconstructed sedimentation rates for 651 lakes across the world to assess the relative changes in lake-watershed erosion rates over the last 12,000 years (Holocene). This synthesis demonstrates that humans have had an effect on erosion rates for millennia, with a first period of global acceleration circa 4,000 cal. BP. Important regional variation in the timing of the onsets of erosion was also apparent and depended on human population density, migration events and farming techniques.

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