Gully evolution and geomorphic adjustments of badlands to reforestation.
Badlands and gullied areas are among those geomorphic environments with the highest erosion rates worldwide. Nevertheless, records of their evolution and their relations with anthropogenic land transformation are scarcer. Here we combine historical data with aerial photographs and tree-ring records to reconstruct the evolution of a badland in a Mediterranean environment of Central Spain. Historical sources suggest an anthropogenic origin of this badland landscape, caused by intense quarrying activities during the 18thcentury. Aerial photographs allowed detection of dramatic geomorphic changes and the evolution of an emerging vegetation cover since the 1960s, due to widespread reforestation. Finally, tree-ring analyses of exposed roots allowed quantification of recent channel incision of the main gully, and sheet erosion processes. Our results suggest that reforestation practices have influenced the initiation of an episode of incision in the main channel in the 1980s, through the hypothesized creation of disequilibrium in water-sediment balance following decoupling of hillslopes from channel processes. These findings imply an asymmetry in the geomorphic response of badlands to erosion such that in the early evolution stages, vegetation removal results in gullying, but that reforestation alone does not necessarily stabilize the landforms and may even promote renewed incision.
Climatic Change and Climate Impacts, Institute for Environmental Sciences, University of Geneva, Boulevard Carl-Vogt 66, CH-1205 Geneva, Switzerland.
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Ballesteros Cánovas
Climatic Change and Climate Impacts, Institute for Environmental Sciences, University of Geneva, Boulevard Carl-Vogt 66, CH-1205 Geneva, Switzerland.|Department of Earth and Environmental Sciences, University of Geneva, CH-1205 Geneva, Switzerland.
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Stoffel
Department of Geodynamics, Complutense University of Madrid (UCM) and IGEO (CSIC, UCM), E-28040, Madrid, Spain.
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Martín-Duque
Centre National de Recherche Scientifique (CNRS) UMR6042 Geolab, F-63006, Clermont-Ferrand Cedex, France.
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Corona
Faculty of Science and Technology, Free University of Bozen-Bolzano, I- 39100, Bolzano, Italy.|Centre of Applied Geosciences, Eberhard Karls University of Tübingen, G- 72074, Tübingen, Germany.
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Lucía
Department of Geological and Mining Engineering, University of Castilla-La Mancha (UCLM), Avda. Carlos III s/n, 45071 Toledo, Spain.
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Bodoque
Department of Earth and Space Sciences. University of Washington, WA 98195, Seattle, USA.
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Montgomery