Climate‐driven decrease in erosion in extant Mediterranean badlands

Abstract

Badland areas provide some of the highest erosion rates globally. Most studies of erosion have insuffi cient lengths of record to interrogate the impacts of decadal-scale changes in precipitation on rates of badland erosion in regions such as the Mediterranean, which are known to be sensitive to land degradation and desertifi cation. Erosion measurements, derived from fi eld monitoring using erosion pins, in southern Italy during the period 1974-2004 are used to explore the impacts of changing precipitation patterns on badland erosion. Erosion on badland inter-rill areas is strongly correlated with cumulative rainfall over each monitoring period. Annual precipitation has a substantial dynamic range, but both annual and winter (December, January, February) rainfall amounts in southern Italy show a steady decrease over the period 1970-2000. The persistence of positive values of the winter North Atlantic Oscillation index in the period 1980-2000 is correlated with a reduction in the winter rainfall amounts. Future climate scenarios show a reduction in annual rainfall across the western and central Mediterranean which is likely to result in a further reduction in erosion rates in existing badlands.

Determinants of plant community composition of remnant biancane badlands: a hierarchical approach to quantify species-environment relationships

“…1, Guasparri 1978; Raglione et al 1980; Alexander 1982). In biancane badlands, erosion has cut through a single substratum of Plio‐Pleistocenic marine clays causing its differentiation into a mosaic of habitats that range from bare ground with scarce or no vegetation to grassland communities with or without shrubs (Chiarucci et al 1995; see Clarke & Rendell 2010). The southern slope of biancane, with marked soil erosion and mass movement, is colonized by scanty vegetation, while pioneer annual vegetation occurs on pediments near the feet of the biancane, representing the equilibrium area between plant colonization and soil sedimentation (Chiarucci et al 1995; Marignani et al 2008).…”

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 1. Methodological development based on high‐resolution topography

“…These values are in agreement with the average values of topographic changes observed in sub‐humid badlands developed on marls for similar study periods (i.e. less than one year; Mathys et al ., ; Clarke and Rendell, ; Nadal‐Romero and Regüés, ; Vericat et al ., ; Smith and Vericat, ; James et al ., ). However, it is worth mentioning that the thresholds between these classes will depend on the considered time span and require what re‐evaluation if the survey interval is altered.…”

21st century climate change: where has all the geomorphology gone?

“…Bauch and Hickin (2011) report that increases in the magnitude and duration of the annual flood is responsible for a dramatic increase in channel activity in the Squamish River, Southern British Columbia, notably in terms of erosion, a change that that they attribute to the intensification of late season Pacific storms. Clarke and Rendell (2010) used three decades of erosion measurement to show that the persistently positive values of the NAO between the 1980s and 2000 were correlated with reduced winter rainfall and that this had reduced Mediterranean badland erosion rates in Italy. Clarke and Rendell (2010) used three decades of erosion measurement to show that the persistently positive values of the NAO between the 1980s and 2000 were correlated with reduced winter rainfall and that this had reduced Mediterranean badland erosion rates in Italy.…”