Soil and plant characteristics in a restored area under mid-term site management

Mid-and long-term monitoring of restoration projects have to be performed, as short-term evaluations do not give comprehensive information about their outcomes. In this study, we assessed the results of a forest restoration project, implemented in former road builder's yards. We evaluated the recovery of the soil's physical and chemical properties, the effectiveness and naturalness of sward restoration, and the success of woody species planting. Our hypotheses were that soil-plant interaction strongly influenced the restoration dynamics. The areas were restored in 2016. In 2014, we collected data from 28 restored areas. Eight years after the restoration, the physical and chemical properties of the soil indicated good quality. Suitable soil conditions were reflected in the herbaceous vegetation cover, which was higher than 60% in all the areas. The sown mixture successfully contained spontaneous species, and perennials prevailed over annuals, indicating stability in the composition of the sward. Alien species cover (generally <10%) was controlled by sown species. Sown species also outcompeted ruderal and typical grassland species, reducing the naturalness of the herbaceous layer. Tree and shrub growth was low, and soil properties did not affect their height. Our results underline the importance of sowing an herbaceous species mixture in degraded areas in order to efficiently restore the soil cover and to reduce the colonization of alien species. Moreover, in our study, we showed how soil properties differently affected plant species groups.