Using the root spread information of pioneer plants to quantify their mitigation potential against shallow landslides and erosion in temperate humid climates

The aim of this paper was to quantify the mitigation potential of pioneer herbs against shallow landslidesand erosion in temperate humid climates and to identify key plant information to aid species selectionfor slope stabilisation. The objectives ranged from the study of the climate, soil and root spread of threenative perennial herbs growing on a landslide-prone slope in Northeast Scotland to the verification of anupgraded spatially distributed eco-hydrological model in order to test whether root spread informationcan be provided cost-effectively in temperate humid climates. The retrieved information on root spreadwas then used to evaluate the slope stabilisation potential of the pioneer herbs in the topmost soilhorizons using a limit equilibrium method.The results indicated that pioneer herbs, although presenting climate-influenced shallow root systems,could noticeably contribute to reducing soil mass loss and landslides. This was largely determined by theplant biomass and allometry, the latter being a potential readily measurable proxy for species selectionin slope stabilisation that will need further investigation. Additionally, our observations supported themodel predictions remarkably well when site-specific inputs were employed, showing that the proposedmodel is a suitable and cost-effective tool to provide spatial root spread information for eco-engineeringpurposes in temperate humid climates

Integrated model for the hydro-mechanical effects of vegetation against shallow landslides

Shallow landslides are instability events that lead to dramatic soil mass wasting in sloping areas and are commonly triggered by intense rainfall episodes. Vegetation may reduce the likelihood of slope failure through different hydro-mechanical mechanisms that take place at the soil-plant-atmosphere interface. However, while vegetation’s mechanical contribution has been widely recognized, its hydrological effects have been poorly quantified. In addition, most of the existing models lack a holistic approach, require difficult to measure parameters or are commercially based, making them hardly transferable to land planners and other researchers.In this paper an integrated, robust and reproducible model framework is proposed and evaluated with the aim of assessing the hydro-mechanical effects of different vegetation types on slope stability using easily measureable and quantifiable input parameters. The output shows that the model framework is able to simulate the hydro-mechanical effects of vegetation in a realistic manner and that it can be readily applied to any vegetation, soil and climate types. It also demonstrates that vegetation has positive hydro-mechanical effects against shallow landslides, where plant biomass and evapotranspiration play an important role