title: Legacy of human-induced C erosion and burial on soil-atmosphere C exchange.
abstract: Carbon exchange associated with accelerated erosion following land cover change is an important component of the global C cycle. In current assessments, however, this component is not accounted for. Here, we integrate the effects of accelerated C erosion across point, hillslope, and catchment scale for the 780-km(2) Dijle River catchment over the period 4000 B.C. to A.D. 2000 to demonstrate that accelerated erosion results in a net C sink. We found this long-term C sink to be equivalent to 43% of the eroded C and to have offset 39% (17-66%) of the C emissions due to anthropogenic land cover change since the advent of agriculture. Nevertheless, the erosion-induced C sink strength is limited by a significant loss of buried C in terrestrial depositional stores, which lagged the burial. The time lag between burial and subsequent loss at this study site implies that the C buried in eroded terrestrial deposits during the agricultural expansion of the last 150 y cannot be assumed to be inert to further destabilization, and indeed might become a significant C source. Our analysis exemplifies that accounting for the non-steady-state C dynamics in geomorphic active systems is pertinent to understanding both past and future anthropogenic global change.
authors.affiliation: Georges Lemaître Centre for Earth and Climate Research, Earth and Life Institute, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium. kristof.vanoost@uclouvain.be
authors.forename: Kristof
authors.initials: K
authors.lastname: Van Oost
authors.forename: Gert
authors.initials: G
authors.lastname: Verstraeten
authors.forename: Sebastian
authors.initials: S
authors.lastname: Doetterl
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Notebaert
authors.forename: François
authors.initials: F
authors.lastname: Wiaux
authors.forename: Nils
authors.initials: N
authors.lastname: Broothaerts
authors.forename: Johan
authors.initials: J
authors.lastname: Six
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D001530:Belgium; D002244:Carbon / Q000032:analysis*; D003247:Conservation of Natural Resources; D005843:Geography; D006801:Humans; D012987:Soil / Q000737:chemistry*; D013997:Time Factors
chemical_list: D012987:Soil; D002244:Carbon