Topographic factors drive natural understory revegetation in burned areas

Abstract Background: In nature, fire is an important disturbance in forest ecosystems and has important impacts on vegetation succession. To reveal the characteristics of natural understory revegetation after burning and its response to environmental factors, we studied burned areas in a subtropical climate (Xide County, China). Results: Based on quadrat surveys and correlation analyses, the main results of this study were as follows. (1) Within four months after a fire, 71 species, 52 genera, and 20 families gained, representing rapid recoveryafter a fire. (2) The Shannon-Wiener, Simpson, and Margalef indexes increased with recovery, whereas the Pielou index decreased; the Margalef index was the most sensitive, increasing by 5.44 and 5.16 in lightly and severely burned areas, respectively. (3) The community stability was relatively low at the initial stage of revegetation andtended to increase with the intensity of the fire. (4) Elevation and slope were the main physical factors affecting the biodiversity indexes and distribution. Conclusions: This study could help us to understand the relationships between revegetation and topographic factors in burned areas, thereby providing a scientific basis for related ecological restoration.