Differentiation of vegetation characteristics on micro-topography in gneiss mountainous area of Pingshan County, Hebei Province of northern China

Micro-topography is a main factor inducing the differences in characteristics of plant community. It is significant to explore the impacts of micro-topography on characteristics of plant community for vegetation restoration and rebuilding in difficult site. Based on the investigation data of vegetation in gneiss mountainous area in Pingshan County of Hebei Province of northern China, this paper analyzes the differences in characteristics of plant community among seven micro-topographies, including slope top, collapse, huge stone shadow, platform, scarp, brae and U-gully, with the undisturbed slope as control, aiming at supplying reference for the revegetation of gneiss mountainous area. The results showed that there existed significant differences in the quantitative characteristics of plant community on the seven micro-topographies and the undisturbed slope. The height, coverage and biomass of the plant community on most of the micro-topographies were better than those on the undisturbed slope (33.64 cm, 59.61%, 291.79 g/m²), at the same time, those indexes were best on U-gully (49.12 cm, 78.02%, 574.84 g/m²) and collapse (50.94 cm, 74.81%, 570.50 g/m²), and worst on scarp (30.65 cm, 62.49%, 89.13 g/m²) and slope top (28.73 cm, 52.67%, 78.36 g/m²). In vegetation diversity of plant community, brae had similar diversity characteristics as the undisturbed slope, they both had fewer species, but higher in diversity indexes and evenness. On account of the abundant species and the higher diversity indexes and evenness, the conditions of vegetation diversity on platform and U-gully were the best. Species on collapse, huge stone shadow and slope top were fewer and unequally-distributed. On these micro-topographies, the status of dominant species was prominent, and existed single dominant population. Although there were abundant species on scarp, the diversity indexes and evenness were low, most of the species were occasional or accompanying. Therefore, for the quantitative characteristics of plant community and vegetation diversity, U-gully, collapse and platform were the better choices for revegetation in gneiss mountainous area.