Flora And Its Ecological Geography Of The Orchidaceae In The Luoxiao Mountains Range,jiangxi Province

The Luoxiao Mountains range is a north-south mountain range.It is located at the junction of Hunan Province and Jiangxi Province.It is the natural boundary between the two provinces and the watershed of the Xiangjiang River and the Ganjiang River.It is 516 km long from north to south and 175-285 km wide from east to west.Based on the field investigation,specimens and literature survey of Luoxiao Mountains range,the flora of the Orchidaceae and its ecogeographical characteristics were analyzed.It was found that the Luoxiao Mountains are rich in orchids.There are about 124 species and 47 genera,of which 80,36 and 8 species are terrestrial,epiphytic and saprophytic,accounting for 64.5%,29.0% and 6.5% of the total species.Among them:(1)There are 77 species and 36 genera of orchids in the Qiyun Mountain Nature Reserve,and 52,20 and 5 species are terrestrial,epiphytic and saprophytic,respectively,accounting for 67.5%,26.0% and 6.5% of the total species.(2)There are 96 species and 39 genera of Orchids in the Jinggangshan Nature Reserve,and 58,33 and 5 species are terrestrial,epiphytic and saprophytic,respectively,accounting for 60.4%,34.4% and 5.2% of the total species.(3)There are42 species and 21 genera of Orchids in the Wugongshan Nature Reserve,and 37,4and 1 species are terrestrial,epiphytic and saprophytic,respectively,accounting for88.1%,9.5% and 2.4% of the total species.(4)There are 38 species and 21 genera of Orchids in the Guanshan Nature Reserve,and 31,5 and 2 species are terrestrial,epiphytic and saprophytic,respectively,accounting for 81.6%,13.2% and 5.3% of the total species.(5)There are 41 species and 27 genera of Orchids in the Jiulingshan Nature Reserve,and 34,5 and 2 species are terrestrial,epiphytic and saprophytic,respectively,accounting for 82.9%,12.2% and 4.9% of the total species.In the horizontal distribution,orchids are concentrated in the Zhuguang Mountains and Wanyang Mountains.From south to north,the species of terrestrial orchids are gradually increasing,and the species of epiphytic orchids and saprophytic orchids are gradually decreasing.In the vertical distribution,orchids are concentrated in the altitude 400-1200 meters.The component of the orchid flora in Luoxiao Mountains range is complex and can be divided into 11 distribution types and 2variants,among which the tropical distribution is the most genus,and the tropical distribution belongs to the total of 31 genera and 80 species,accounting for 66.0%and 64.5% of the total genera and total species in the region;Temperate distribution of 13 genera and 30 species,accounting for 27.7% and 24.2% of the total number and total species of the region;Orchid plants in the Luoxiao Mountains are dominated by tropical and subtropical components and are affected by temperate components.Cluster analysis found that Guanshan Nature Reserve and Wugongshan Nature Reserve were grouped together,and then clustered together with Jiulingshan Nature Reserve.Finally,they were clustered together with Jinggangshan Nature Reserve;Qiyun Mountain Nature Reserve alone class.The comprehensive analysis indicated that the flora of Orchidaceae in Luoxiao Mountains range is relatively complex,its tropical relationship is strong,its origin is ancient and its differentiation degree is high,which plays an important role in the study of orchid system and evolution.In addition,the analysis of the endangered status of orchid plants and the corresponding protection strategies and recommendations are of great significance to the development,utilization and protection of orchid resources in the region.