Abstract: To study spatial variation of plant functional type and biodiversity in various functional zones of the Hui River National Nature Reserve, vegetation survey were conducted in the core area, the buffer zone, and the experiment zone in the reserve, using the sample transects and plots method. Three plots (250 × 250 m), almost the same in habitat condition, were selected, and in each plot three transects and in each transect eight quadrats (1 × 1 m) were set up for analysis of spcies richness index, species diversity index, species diversity index,biomass and spatial variability of life-form plant functional type in different functional areas of the reserve . Results show that in the study area, the vegetation was dominated with perennial forbs and perennial grasses; in the core area and buffer zone, the vegetation was also dominated with a huge variety of perennial grasses and perennial forbs, and only dotted with some annual herbs, while in the experiment zone, the number of functional species, like perennial grasses and perennial forbs, declined markedly, but the population of annual herbs grew. Moreover, the dominance of shrubbery gradually increased from the core and buffer zone to experiment zone. The buffer zone did not differ much from the core area in dominance of perennial grasses and perennial forbs (P > 0.05); however, in the experiment zone, the dominance was significantly weakened (P< 0.05). The dominance of annual herbs gradually stepped up from the core area to the buffer zone and experiment zone. Biomass of perennial grasses and perennial forbs and total biomass of plant community in the three areas showed a declining order of core zone > buffer zone > experiment zone, however, biomass of shrubs and annual herbs increased in a reverse order. The species richness index of the buffer zone was the highest, and significantly higher than that of the experiment zone (P< 0.05),while Shannon-Wiener index and Pielou index did not vary much between the core area and buffer zone (P< 0.05).

Key words: plant functional types, spatial variability, Hui River Nature Reserve, Inner Mongolia