Study On Orchidaceae Flora And Ornamental Application In Panxi

Based on the investigation of wild Orchidaceae resources in Panxi area,referring to a large number of historical data and consulting relevant experts and scholars,this paper mainly carried out the following two studies: first,from the floristic composition,floristic nature,geographical connection,floristic evolution and other aspects,the Orchidaceae flora in the study area was deeply studied and discussed Species richness,species differentiation and R / T value were compared with other Orchidaceae flora;Secondly,for the purpose of landscape ornamental application,referring to the relevant wild plant resources evaluation research,according to the actual field investigation,the comprehensive evaluation system of wild orchid resources was constructed by combining qualitative and quantitative methods,and the development and utilization levels of different orchid species were determined through the evaluation.The main research results are as follows(1)There are abundant species of Orchidaceae in Panxi area: there are 53 genera and 165 species of Orchidaceae,including genera of single species,few species and many species with the number 24,21 and 8,which accounting for 45.28%,39.62%and 15.09% of the total genera respectively;there are three life forms include terrestrial orchid,epiphytic orchid and saprophytic orchid,with 137 species(83.03%),21 species(12.73%)and 7 species(4.24%)respectively;and there are 57 species of Orchidaceae endemic to China,accounting for 9.48% of the total Orchidaceae endemic to China.In addition,16 species of Orchidaceae that have not been recorded in Sichuan Province are also involved in this survey.(2)The complex and diverse floristic components of Orchidaceae in Panxi Area:there are 11 distribution types and 5 varieties,according to the subordinate geographical distribution types.Further divided into 2 widely distributed genera in the world,26 tropical genera,16 temperate genera and 9 East Asian genera,which accounting for 3.77%,47.06%,30.19% and 16.18% of the total genera respectively,besides having 1 Chinese endemic genus.The R / T value of genus level is 1.08,which is mainly tropical and has the characteristics of tropical affinity.At the species level,there are 52 tropical species,accounting for 31.52% of the total species;10north temperate species,accounting for 6.06% of the total species;103 East Asian species,accounting for 62.42% of the total species,including 57 endemic to China,accounting for 34.55%.The R / T value of species grade was 0.93,which was dominated by temperate components.(3)The results show that the differences of Orchidaceae flora in Panxi area are prominent,the geographical connection is extensive,and the transition nature is obvious: the Orchidaceae species in the study area are regionally endemic and Chinese endemic,and the regional differences are significant;in terms of similarity coefficient,the Orchidaceae flora in Panxi area is more or less related to most regions of China,and the species richness and genus species differentiation in the study area are high,It is speculated that Panxi area is located in the center of a large-scale flora.In addition,according to the analysis of R / T latitudinal law of various flora genera and species,Panxi area is likely to be located in the transition region from subtropical to temperate zone of Orchidaceae in China and even Central Asia.(4)The evaluation system of wild orchid resources was established for the purpose of landscape ornamental application.The system was composed of four indexes: ornamental value,protection level,total amount and distribution of resources.AHP and cluster analysis were used to evaluate the resources.According to the evaluation results,the development and utilization levels of wild orchid plants were divided into priority species,general species and temporarily undeveloped species Species.By using the evaluation system,15 priority species were screened out,accounting for 20.27% of the total species;28 common species,accounting for 37.84%of the total species;31 species,accounting for 41.89% of the total species,were temporarily not developed.It provides a theoretical basis for the scientific and rational use of orchid plants.