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TitreClimate and human influences on global sediment transfers during the past 10,000 years
AuteurJenny, J -P; Carvalhais, N; Francus, P; Koirala, S; Gregory-Eaves, I; Niemann, C; Arhens, B; Baud, A; Ojala, A E K; Normandeau, A; Zolitschka, B
SourceIPA-IAL 2018 Joint Meeting: Unravelling the Past and Future of Lakes, abstract book; 2018 p. 4
LiensOnline - En ligne (complete volume - volume complet, pdf, 20.7 MB)
Année2018
Séries alt.Ressources naturelles Canada, Contribution externe 20180264
ÉditeurStockholm University
RéunionIPA-IAL 2018 Joint Meeting: Unravelling the Past and Future of Lakes; Stockholm; SE; juin 18-21, 2018
Documentlivre
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceCanada; Colombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 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 OENS-180.0000 180.0000 90.0000 0.0000
SujetsHolocène; transfert des sédiments; érosion; taux d'érosion; débit de sedimentation; eaux de surface; lacs; bassins versants; carbone; paléoclimatologie; datation radiométrique; datation au radiocarbone; datations au C-14; analyses palynologiques; pollen; modèles; changement climatique; paléolimnologie; géologie de l'environnement; géologie des dépôts meubles/géomorphologie; pédologie; géochronologie; Agriculture; Nature et environnement; Phanérozoïque; Cénozoïque; Quaternaire
ProgrammeDivision de la CGC atlantique, Bureau du directeur
Diffusé2018 06 01
Résumé(disponible en anglais seulement)
Accelerated soil erosion has substantial implications for land productivity, downstream lake ecosystems and biogeochemical cycles1,2. However, the lack of long-term instrumental data and the scarcity of large-scale paleolimnological synthesis are limiting our understanding on the timing, the amplitude and the extent of soil erosion for the last millennia3. As such, the responses of soil erosion to long-term climate and land cover changes, the effects on lakes C accumulation and the feedbacks on the climate system are still unclear today4. Here, we reconstruct sedimentation rates based on 14C chronologies for 651 lakes to assess the relative changes in lake-watersheds erosion over the period 12,000 B.C. to A.D. 2000. Estimated soil erosion dynamics are then complemented with land cover reconstructions inferred from pollen records and with JSBACH-model climate reconstructions. We find a constant trend in our global signal of inferred-erosion during the Holocene until trends started to increase at the continental scale beginning around 3,000 years ago, with large spatial heterogeneity between local trends. In particular, increased inferred soil erosion is recorded in 35.1% watersheds, and most of these sites show a decrease in arboreal pollen that is congruent with the erosion rate changes. Further analysis reveals that land cover change is the main driver of soil erosion in 70% of all studied watersheds. Most of erosion variations in the last 50 years are related to agricultural intensification rather than land clearance or predominance of agricultural lands5. In contrast our synthesis strongly suggests that - at least in the Northern Hemisphere - human land cover change has been the primary driver of accelerated erosion during the Holocene.
Résumé(Résumé en langage clair et simple, non publié)
Nous avons reconstitué les taux de sédimentation par datation par 14C de 651 lacs afin d'évaluer les changements relatifs de l'érosion des bassins hydrographiques depuis 12?000 ans av. J. C. jusqu'à l'an 2000. Nous constatons une tendance constante dans la signature de l'érosion déduite à l'échelle planétaire pendant l'Holocène, jusqu'à ce que la tendance à l'érosion commence à augmenter à l'échelle continentale il y a environ 3000 ans.
GEOSCAN ID313024