Spontaneous succession on road verges—An effective approach with minimum effort

Abstract

AbstractRoad verges represent new habitats providing an opportunity for enhancing biodiversity in human‐altered landscapes. However, it is common practice to plant trees or sow species‐poor seed mixtures regardless of their geographical origin. We assessed the effectiveness of spontaneous restoration to fulfil the requirements for both functions, the formation of vegetation cover to prevent erosion and native species‐rich vegetation, which may provide conservation benefits. We sampled 113 vegetation plots on road verges in the Czech Republic, central Europe. The sampling plots were 25 m2 in size and differed in age (1–42 years). We recorded surrounding landscape (land‐cover categories, landscape heterogeneity, and length of roads and railways in a 1‐km radius zone) and site factors (altitude, substrate texture, slope, aspect, and potential solar radiation) and analysed the data using multivariate methods. Species composition was significantly explained by successional age, altitude, substrate texture, and surrounding forest area. The total herb cover reached on average 30% already in the first 2 years, and later shrub and tree layers developed. Out of 320 identified vascular plant species, almost 5% (15 species) were endangered and 6% (19 species) were invasive aliens. Early successional stages were characterised by a high cover of insect‐pollinated species, which can serve as important food sources for insects. Despite some limitations (poor seed sources and inconvenient site conditions), our results showed that spontaneous succession could be used more often in the restoration of road verges because this approach may provide an alternative, cost‐effective solution of reasonable conservation value.