Abstract: This paper studied the edge effect of road in the forests in Dinghusha n Natural Reserve of Guangdong Province, and approached the effects of road in f orests on forest ecosystem. Four 30 m×5 m transects with a distance of 0, 10, 2 0, and 30 m from the both sides of a 6-m-wide winding mountain road were insta lled to conduct vegetation investigation and soil analysis. The results showed that t he total tree biomass in the transects adjacent the road was slightly higher tha n that of the inner forest communities, showing a positive edge effect, while th e soil acidity and total nitrogen content in downgrade transects showed a negati ve edge effect. Neither species diversity nor soil moisture content exhibited ob vious edge effect. As a whole, road construction had definite negative effects o n the integrality of forest ecosystem, producing artificial linear gaps and gene rating edge effect in the characteristics of vegetation and soil. The edge effec t caused by forest road should be considered in the management of Natural Reserv e.

Key words: Oryza sativa, Allelopathy, Terpenoids, Allelochemicals