Plant functional trait effects on runoff to design herbaceous hedges for soil erosion control

Abstract

Vegetation controls concentrated runoff and erosion in the European loess belt by increasing hydraulic roughness and sediment retention. Studies of plant effects on runoff velocity are usually based on a taxonomical characterisation and do not consider the effects of aboveground plant functional traits in attempts to understand soil erosion by water. This trait-based plant study investigates aboveground plant functional trait effects of herbaceous hedges on the hydraulic roughness to understand soil erosion. Eight aboveground functional traits were measured on fourteen indigenous and perennial plant species (caespitose or comprising dry biomass in winter) from northwest Europe with a high morphological variability. For each trait, density-weighted traits were calculated. ACCEPTED VERSION 2 The effects of functional traits and density-weighted traits were examined using a runoff simulator with four discharges. The leaf density and area, as well as density-weighted stem and leaf areas, stem diameter and specific leaf area were positively correlated with the hydraulic roughness. Generalised linear models defined the best combinations of traits and density-weighted traits: (1) leaf density and leaf area, (2) density-weighted leaf area and density-weighted projected stem area, and (3) density-weighted leaf area and densityweighted stem diameter. Moreover, the effects of leaf density, leaf area and densityweighted specific leaf area, varied depending on the discharge. This study is one of the first characterisation of aboveground trait effects on hydraulic roughness and highlights that vegetation with important stem density, diameter and leaf area plays a significant role in minimising soil erosion. The selection of plant species can derive from these plant trait effects to design reconstructed herbaceous hedges to minimise soil erosion.

Digital Mapping of Habitat for Plant Communities Based on Soil Functions: A Case Study in the Virgin Forest-Steppe of Russia

“…On the whole, the mesophyte communites on Phaeozems includes more herbs and Carex species with bigger leaf area than the species of communities on Chernozem. In accordance with [12,[45][46][47][48] the plants of mesophyte phytocenoses could increase hydraulic roughness, sediment retention, and minimize soil erosion in comparison with the plants of xero-mesophyte phytocenoses.…”

Functional Diversity Effects of Vegetation on Runoff to Design Herbaceous Hedges for Sediment Retention

“…A positive relationship between the aboveground biomass and hydraulic roughness was highlighted, as an increase in the biomass productivity would further hydraulic roughness and sediment retention [25]. The aboveground functional traits that directly impact the hydraulic roughness for erosional events found under temperate climates were identified by Kervroëdan et al [26]-herbaceous vegetation with important leaf density, leaf area, stem diameter, and stem projected area (stem area toward the flow direction) were found to be the most efficient in increasing hydraulic roughness. Nonetheless, these results emphasized the effects of negatively correlated trait combinations (i.e., leaf density and area) involved in hydraulic roughness increase, which suggested that communities with a high functional diversity would reach the best trade-off to maximize the vegetation effects on hydraulic roughness.…”

“…Four indigenous plant species from North-West Europe that presented selected functional types, contrasting aboveground functional traits, and that were involved in the increase of hydraulic roughness (leaf-area and density; stem-projected area, diameter, and density) [26], were used in the present study. The chosen plant species presented a minimal vegetative height within the range of 20 and 60 cm, in order to limit competition for light and ensure a uniform development of each species in the plots.…”

“…Hydraulic roughness is defined as frictional resistance due to the contact of runoff with the vegetation [20][21][22][23][24]. Hydraulic roughness of herbaceous vegetation furthers sediment retention by reducing flow velocity; however, it is highly variable depending on the plant species and traits [21,[24][25][26][27][28][29]. A positive relationship between the aboveground biomass and hydraulic roughness was highlighted, as an increase in the biomass productivity would further hydraulic roughness and sediment retention [25].…”

Integrating co‐production and functional trait approaches for inclusive and scalable restoration solutions

“…After setting the vision, goals, and scenarios, we conducted a functional trait analysis following the steps described in Ostertag et al (2015) (Figure 2). For each scenario, we Large leaves have a large interception area, which can protect soil from rainfall and increase sediment trapping ability (Burylo, Dutoit, & Rey, 2014;Burylo, Rey, Bochet, & Dutoit, 2012;Kervroëdan, Armand, Saunier, Ouvry, & Faucon, 2018) 0.11-12,240…”