Aalynological assemblage characters and the ecologic significanceamong rocky desert of different grades — A case in Huajiang

Taken the demonstration plot in the Beipangjiang basin to the south Guangling County, Guizhou Province as an example, the authors analysis palynological assemblage characters from surface soil among rocky desert of different grades, reveal the relations between n palynologyical assemblage characters and rocky desertification grades. The results show that the palynological assemblage characters is of distinct individuality in rock desert with 16.1% of arbor and shrub and 58.9% of herb and fern, which reflects herb and fern are the dominate plants in the vegetation of rock desert. The results also show that the palynological assemblage quite correlates to the grades of rocky desert, i.e. the content of herb and fern goes up from 41% to 77.6% wit h the species from 14 up to 27, but the content of arbor goes down from 6.9% to 2.6% without species changes along with the increases of the grades of rocky desert. The palynological assemblage characters reflect that ferns like Pteris trifur cata Ching can adapt the desert environment and has representativeness in these regions.