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Abstract: Goals: To analyze the relative importance for litter decomposition rates of the type of roadslope, topsoil addition and the chemical composition of litter from grasses and legumes commonly used in roadslope restoration, and assess the implications for roadslope restoration and management. Methods: Decomposition rates of four grasses and four legumes (leaves and stems) were compared after 3, 6 and 12 months of roadslope revegetation on embankments and roadcuts. To separate the effect of topsoil from other characteristics of each type of roadslope, a greenhouse litter decomposition experiment was also conducted for periods of 2, 4 and 6 months in pots with and without topsoil addition. Results: At the end of both experiments, the percentage of organic matter remaining (OMR) from legumes was lower than that of grasses (0.33% and 0.47% in the field experiment, 0.42% and 0.53% in the greenhouse), and decreased exponentially with time in all cases during the first year. These differences in decomposition rates between legumes and grasses were related to the chemical composition of their litter. Legume litter decomposes more quickly than grass litter due to its higher N and lignin content and its lower hemicellulose content. The type of roadslope did not influence the OMR in the field experiment. In the greenhouse experiment, OMR was slightly lower in samples without than those with topsoil, but only at the end of the experimental period, when greater humidity in the latter pots probably reduced the enzymatic activity of the microbial community. Conclusions: We conclude that litter chemical composition is more important for litter decomposition than the type of roadslope or topsoil addition, possibly due to the poor soils in the study area. In the light of these results, we recommend a higher percentage of legumes than grasses in restoration projects with a view to reducing litter accumulation on roadslopes and lowering fire management expenditure. [Copyright &y& Elsevier]

Aims Studying plant ecological succession provides insights into the spatiotemporal processes underlying community assembly and is of primary importance for restoration ecology. We investigate here colonization events and local community assembly over an original primary succession occurring on roadcuts after roadwork. For this, we addressed both the changes in species presence-absence (incidence data) to highlight pre-establishment filters and in species relative abundances to further assess the influence of local biotic processes. Methods We studied 43 limestone roadcuts in Mediterranean France, covering five age classes up to an age of 80 years, along with 13 natural cliffs as a reference, and we counted 14322 plant individuals on these sites. We applied a constrained nonsymmetric correspondence analysis of both the incidence (presence-absence) and abundance data to assess the variation of these data along the chronosequence. Important Findings Along the first 30 years, the initially abundant short-lived species declined both in terms of incidence and abundance and were replaced by longer lived herbaceous and woody species. This first phase was characterized by species that are widespread in the surrounding scrublands and was comparable to an early secondary succession there. After 30 years, there were continuing changes in incidence data with age, but no more significant change in species’ abundances. This second phase was marked by the late colonization of specialists that did not become dominant. Although colonization and establishment limitation was thereby apparent for specialist species, a slow convergence of community composition toward the situation of natural cliffs could be detected in the older stages of the chronosequence. These findings convey insights into the natural dynamics of man-made outcrop plant communities and may be useful for the ecological management and restoration of such contexts. It also illustrates the interest of comparing incidence and abundance data to investigate the relative influence of ecological determinants on the assembly of plant communities. [ABSTRACT FROM AUTHOR]

Cutslopes created by earthworks are a challenge for restoration practitioners. A clear and ecological understanding of environmental constraints is a requirement for successful revegetation. This study was conducted to evaluate the effects of solar radiation exposure (SRE) on short-term plant establishment on road cutslopes after hydroseeding herbaceous plants. The study site is located in gneissic hills (Vigo, Northwest Spain) that were excavated by roadworks. Cutslope steepness is higher than 50° and three aspects (SW, S and SE) were used as SRE treatments. Neither hardness nor surface roughness were significantly different among aspects. There were small significant differences in irradiance among aspects, however, the daily peak had a delay from SE to SW. This irradiance pattern probably accounts for a trend in temperature increase and moisture decrease along the gradient SE–SW–S. Water availability for plants is likely to decrease along this gradient, S being the driest topoclimate. A significant coincident trend of decrease in plant density, plant biomass, total plant cover and seedling development was observed along the SE–SW–S gradient. Moreover, seedling density was extremely low in all aspects, demonstrating the prevailing strong environmental constraints of the site. SRE may affect the early establishment and development of herbaceous plants at cutslopes. Therefore, a good project design for cutslope reclamation should adequately consider local topoclimatic conditions. [Copyright &y& Elsevier]

Despite the advances in restoration methods for newly created road habitats such as roadcuts and embankments, implementation in different parts of the world is limited by high cost and lack of knowledge of naturally formed plant communities. However, a cheaper alternative is to relay in natural successional process in sites under optimal conditions. Thus, the first steps should focus on identifying plant species that colonize roadways and road habitats as well as optimal colonization sites. Our study aimed to describe species composition, exotic species presence, and diversity among four roadways (Jeongok-Youngjung, JG; Seolma-Gueup, SM; Singal, SG; and Samga-Daechon, DC) and three habitat types (embankments, plain areas, and roadcuts) in South Korean peninsula. The effect of some environmental factors on plant composition was also examined (soil type, soil slope, and surrounding landscape). Our results showed that established plant species composition was influenced by the interaction between roadways and habitats types, which was also the main interaction affecting plant richness and evenness. Surprisingly, environmental variables had no effect on plant species composition, with a residual amount of explained variation. A total of 48 plant species were described as indicator of different roadways and habitat types, and 50% of them were invasive or cultivated species. It appeared that different regional-dependent processes, such as northern vs. southern roadways, interact with local process in new-road habitats, producing complex patterns of plant species colonization and composition. Thus, ecological restoration solutions should be targeted at site-specific needs (local) while taking into consideration the differences between northern and southern roadways (regional). Here, regional-pool and local-constraints interaction controls plant composition and diversity during road construction in South Korea. Finally, new restoration actions should be based on plant species that have been established spontaneously in these degraded areas. Unlabelled Image • Ecological restoration is limited by illiteracy of naturally formed plant communities in degraded sites. • Four S Korean roadway plant communities were monitored to have insights on restoration potential. • Habitats such as embankments, plain areas, and roadcuts conditioned plant species composition. • Regional and local process interacts making complex plant colonization or compositional patterns. • Restoration plans should base on plant species established spontaneously in road degraded areas. [ABSTRACT FROM AUTHOR]