The Natural Restoration Capability of Vegetation in Different Site Types along the Expressway 25, Lu-Su Section, China

Abstract

The natural restoration capability of vegetation along the expressway is of vital importance for the slope revegetation and maintenance. The Margalef 's richness indexes (DMA), Shannon-Wiener's diversity index (Hp), Pielou's evenness (Jsw), Simpson Index (C), Importance Value Index (IVtr), Vegetation coverage and soil seed bank were used to assess the vegetation restoration capability of the expressway 25, Lu-Su section in China. Seventy-four quadrats ranged from 1 m X 1 m to 20 m X 20 m were studied and the analytical results indicated that Digitaria sanguinalis, Setariaviridis and Gramineae are the dominant species in the expressway slopes. Texture is the most important factor influencing the α diversity and vegetation coverage. Cinnamon soil is more suitable for the restoration compared with slopes the other kind of texture. The land use type and alien species invasion along the expressway are also vital important for the natural restoration. The soil seed bank in filling slope is more abundant than that of excavation slope. The natural restoration of vegetation along the expressway varies according to the site types and land use and most of the slopes have strong recovery ability.