Effects of low-scale landscape structures on aeolian transport processes on arable land

SIEGMUND, NICOLE; FUNK, ROGER; KOSZINSKY, SYLVIA ; BUSCHIAZZO, DANIEL E.; SOMMER, MICHAEL

Aeolian Research

Elsevier

Lugar: Amsterdam; Año: 2018 vol. 32 p. 181 - 191

1875-9637

The landscape of the semiarid Pampa in central Argentina is characterized by late Pleistocene aeolian deposits,covering large plains with sporadic dune structures. Since the current land use changed from extensive livestockproduction within the Caldenal forest ecosystem to arable land, the wind erosion risk increased distinctly. Wemeasured wind erosion and deposition patterns at the plot scale and investigated the spatial variability of theerosion processes. The wind-induced mass-transport was measured with 18 Modified Wilson and Cooke samplers(MWAC), installed on a 1.44 ha large field in a 20 × 40 m grid. Physical and chemical soil properties from theupper soil as well as a digital elevation model were recorded in a 20 × 20 m grid. In a 5-month measuringcampaign data from seven storms with three different wind directions was obtained. Results show very heterogeneouspatterns of erosion and deposition for each storm and indicate favoured erosion on windward anddeposits on leeward terrain positions. Furthermore, a multiple regression model was build, explaining up to 70%of the spatial variance of erosion by just using four predictors: topsoil thickness, relative elevation, soil organiccarbon content and slope direction. Our findings suggest a structure-process-structure complex where thelandscape structure determines the effects of recent wind erosion processes which again slowly influence thestructure, leading to a gradual increase of soil heterogeneity.