Spatial variation of soil properties and plant colonisation on cut slopes: a case study in the semi-tropical hilly areas of China

Abstract

Background: Transport infrastructure has severe impacts on ecosystems and results in large numbers of cut slopes, which are difficult to revegetate. To increase successful revegetation, it is crucial to understand the relationships of soil properties and vegetation during spontaneous vegetation recovery on cut slopes.Aims: To assess the effects of different slope positions on soil properties and vegetation on a cut slope and to determine the key factor(s) affecting vegetation distribution on a cut slope in a semi-tropical environment.Methods: Soil samples were collected in three slope positions: upper slope (US), middle slope (MS) and foot slope (FS). Soil pH, moisture and bulk density and concentrations of soil organic carbon (C), total nitrogen (NT), available nitrogen (NA), total phosphorus (PT), available phosphorus (PA), total potassium (KT) and available potassium (KA) were determined. Vegetation composition and cover were recorded along the slope. One-way analysis of variance (ANOVA), indicator species analysis (ISA) and detrended canonical correspondence analysis (DCCA) were applied to analyse differences in soil properties among slope positions and vegetation distributions.Results: NT, NA, PT, PA, KA, C and pH tended to increase from the US to the FS. Two indicator species were abundant in their respective slope positions: Achyranthes bidentata in the FS and Dicranopteris dichotoma in the US. DCCA showed that pH and some soil nutrients (NA, PT, PA and C) influenced the vegetation distribution on cut slope.Conclusions: Soil pH and some soil nutrients including NA, PT, PA and C had large impacts on vegetation distribution along slope positions in a semi-tropical area of China. We suggest increasing soil pH to provide a better soil environment for plant colonisation in further research concerning the restoration of such cut slopes.