Analysis On Community Features Of Rock Plant Of Danxia Landform In Fangyan

As the core of Fangyan state-level scenic spot, fangyan belongs to Danxia landform, which characterized by lots of dan wall and bare rock, the geological landscrape there is quite attractive. Rock plant was taken to research as the object in this paper, according to slope position and elevation, some plots were established randomly in different environment to survey the vegetation and analyse the floristic situation, geographical composition, quantitative distribution and species diversity. The results as follow:1,There are 128 species of higher plants in Fangyan scenic spot, belonging to 61 families and 103 genera, in which the bryophytes accountes for 12 families, 15 genera and 17 species, the pteridophyte 10 families, 13 genera and 17 species, the spermatophyte 39 families, 75 genera and 94 species. There are many families and genera which contain only one species in the community, the floral composition is so scattered that the genera which have one species occupies 81.33% in the whole, some species have apparent superiority, so do some families such as Compositae,Crassulaceae,Gramineae.2,The Danxia rock plant community has conspicuous temperate and sub-tropical features, with some tropical features. From the level of family, some composition that belonging to world and tropical hold 53.9% and 38.4% in the whole; from the level of genera, the temperate takes most part, with the proportion of 50.7%; from the level of species, the floral composition is corresponding to its'geography location.3,From the level of individual quantitative, the dominance of the dominant species is high. Rubus hirsutus and Sedum fangyanense take the first place separately in shrub-layer and herb-layer, with proportion of 27.59% and 14.33%. Although the community is at the mature stage of evolution, the species'individual quantitative are not on the same level, in the top 10 of individual quantitative, the first and the last are far from each other. From the level of importance value, Vitex negundo var. cannabifolia, Spiraea blumei and Lespedeza bicolor take top 3 separately in shrub-layer where species is quite scattered; in herb-layer, the dominance of Sedum is apparent, which occupies 5 place in top 20.4,After calculating and analysising every plot with species diversity index, showes the Margalef index, Simpson index and Shannon-Wiener index are biggest in plot 17, which has 26 species, with average quantity and no dominant species exists. This phenomenon may be related to this plot's southeast slope and speical environment that plant likes sun and plant hates sun could survive jointly. Comparing three index of every plot, they emerges similar diversification trend.5,According to different environment of rock plant, combining with landscape application and collocation, choose high-quality rock plant materials, and make basic probe in rock garden,rockery greening and slope repairing.