Identifying plant traits: A key aspect for species selection in restoration of eroded roadsides in semiarid environments

Abstract

a b s t r a c tSelecting suitable species for revegetation purposes represents a great challenge for practitioners and scientists, especially in semiarid regions where restoration projects often yield unsuccessful results. So far, little attention has been paid to plant traits related to species success in roadside ecosystems.We aimed at (1) identifying plant traits associated with species success on four roadside situations that span a gradient of productivity and erosion stress and (2) providing an ecological base for selecting suitable species on the basis of their functional traits, applied to semiarid environments.We tested the general hypothesis that trait distribution of successful roadslope colonizers results from a filtering process which is mainly controlled first by seed availability and dispersal and then by plant competition on north-facing roadfills and by environmental harshness on south-facing roadcuts. We analyzed the contribution of 10 plant traits selected as regards the prevailing limiting processes acting along the erosion-productivity gradient in semiarid roadslopes to species colonizing success.A large database of 296 species × 10 traits based on leaf, seed and root measurements is provided. Abundance in the neighbouring vegetation, ability of diaspores to long-dispersal and non-random trait filtering through abiotic and biotic filters, all influenced roadslope community assembly. Along the stressproductivity gradient, we observed strong shifts in the traits associated to species success. At the most productive end, species success was associated to a competitive-ruderal strategy (herbaceous successful species with high SLA and low LDMC values) and, at the harshest end, species success was related to seed resistance to removal by runoff and to resistance to drought (seed mucilage secretion and low index of seed susceptibility to removal).We provide an ecological basis for selecting suitable species on the basis of morphological and functional plant traits, which is potentially of great benefit to practitioners and policy makers involved in roadside restoration in semiarid environments.

Designing seed mixtures for restoration on alpine soils: who should your neighbours be?

“…There is considerable inappropriate use of seed mixtures in restoration projects (Fagan et al. ; Bochet & García‐Fayos ). This includes: using seed mixtures at sites where seeding is unnecessary and natural recovery (passive restoration) is more appropriate; using unsuitable seed mixtures so that species interactions alter the outcome or increase the expense; using unsuitable seed mixtures containing species that are not well adapted to environmental conditions at the site in question; and using introduced seeds of species that are native to the area, causing genetic risk (Falk et al.…”

A tale of two green walls: a functional trait approach to assess vegetation establishment on restored steep slopes

“…GW1 is southeast‐facing, while GW2 is northwest‐facing, which may influence several microclimatic factors and consequently the structure and composition of plant communities. Indeed, higher values of solar radiation and temperature, and lower soil moisture, are usually associated with south‐facing slopes, therefore characterized by harsher environmental conditions (Cano et al ; Martínez‐Ruiz et al ; Bochet & García‐Fayos ). Several authors have reported differences in vegetation cover and species diversity in revegetated road slopes along gradients of aspect (Bochet et al ; Bochet et al ).…”

Correlating hydrologic reinforcement of vegetated soil with plant traits during establishment of woody perennials

“…Under European temperate climate condition, deciduous species are generally characterized by high SLA and hence a faster return of energy investment and transpiration during summer growing season (Bai et al 2015). A recent study by Bochet and García-Fayos (2015) showed that SLA was a relevant trait for indicating plant competitivity and the establishment success on road embankments in semi-arid environment. Thus, SLA, whose measurement is relatively simple and quick, appears to be a useful plant screening trait that could be used to assess the relative hydrologic reinforcement and survival under the harsh environment of engineered slopes.…”