Impact of vegetation on erosion: Insights from the calibration and test of a landscape evolution model in alpine badland catchments

Abstract

While it is well recognized that vegetation can affect erosion, sediment yield and, over longer timescales, landform evolution, the nature of this interaction and how it should be modeled is not obvious and may depend on the study site. In order to develop quantitative insight into the magnitude and nature of the influence of vegetation on catchment erosion, we build a landscape evolution model to simulate erosion in badlands, then calibrate and evaluate it against sediment yield data for two catchments with contrasting vegetation cover. The model couples hillslope gravitational transport and stream alluvium transport. Results indicate that hillslope transport processes depend strongly on the vegetation cover, whereas stream transport processes do not seem to be affected by the presence of vegetation. The model performance in prediction is found to be higher for the denuded catchment than for the reforested one. Moreover, we find that vegetation acts on erosion mostly by reducing soil erodibility rather than by reducing surface runoff. Finally, the methodology we propose can be a useful tool to evaluate the efficiency of previous revegetation operations and to provide guidance for future restoration work. © 2019 John Wiley & Sons, Ltd.

Biogeomorphology, quo vadis? On processes, time, and space in biogeomorphology

“…(2019), Carriere et al . (2020), and Nardin et al . (2020) use available mechanistic models (Delft3D and Landlab); Dong et al .…”

“…Pawlik et al ., 2016; Pawlik and Šamonil, 2018; Giaccone et al ., 2019). Biogeomorphic evolution and succession across the decadal to centennial scale have also been studied by contrasting hillslopes with different aspects (McAuliffe et al ., 2014; Stavi et al ., 2018; Carriere et al ., 2020).…”

“…(2019) and Carriere et al . (2020) investigate landscape stability and evolution due to the influence of vegetation on surface processes (and vice versa). Within most of these studies, the feedback systems between the shallow groundwater and soil water, and vegetation dynamics, emerges as important in driving geomorphic feedbacks.…”

“…For intermediate scales (decadal to centennial), the literature shows a peak in contributions (Figure 2), likely related to the rise of numerical modelling (Kleinhans et al ., 2019; Lera et al ., 2019; Nardin et al ., 2020), as well as remote sensing techniques (Gurnell et al ., 2019; Corenblit et al ., 2020) for biogeomorphological research. At the largest scales, a more rule‐based understanding of system behaviour is established (Larsen et al ., 2019; Carriere et al ., 2020). In other words, biogeomorphological research is conducted at many scales and elucidating many feedback systems, but there is now a particular need for research into cross‐scalar effects and how biogeomorphology can contribute further to environmental management, for example by employing NbS.…”

“…Substantial advances have been made in understanding, quantifying, and modelling feedbacks between vegetation, fluvial, and coastal dynamics. In this issue, Jerin and Phillips (2020) focus on the influence of mature tree species in creating pools in bedrock channels, while Kleinhans et al (2018Kleinhans et al ( , 2019 Carriere et al (2020) investigate landscape stability and evolution due to the influence of vegetation on surface processes (and vice versa). Within most of these studies, the feedback systems between the shallow groundwater and soil water, and vegetation dynamics, emerges as important in driving geomorphic feedbacks.…”