Distribution And Habitat Study Of Orchid Resources In Inner Mongolia

Orchidaceae is the second largest family of angiosperms,with certain ornamental,cultural,and medicinal values,and has a certain indicative effect on the quality of the ecological environment.Inner Mongolia spans the three northern regions and is the third largest province in China.The vegetation changes from east to west are significant,and wild animal and plant resources are abundant.However,there is a lack of research on the species,quantity,and distribution patterns of this family of plants.This article investigates the wild orchid plant resources in Inner Mongolia,and based on their latitude and longitude information and climate data,uses methods such as Jaccard similarity coefficient,canonical correspondence analysis(CCA),and multiple regression analysis based on generalized linear model(GLM)to clarify the species composition,distribution characteristics,and response patterns of orchid plant species to habitat changes,and to supplement and improve the background information,Provide theoretical basis for future conservation and development of orchid plant resources.After research,the following conclusions have been drawn:1.Field investigation revealed that there are 14 genera and 19 species of orchids in the family Orchidaceae,among which 11 genera and 16 species are classified accordi ng to their life forms,accounting for 85.71% and 89.47% of the total genera and species,respectively;There are 3 genera and 3 species of saprophytic orchids,accounting for14.29% and 10.53% of the total genera and species,respectively.There are no ep iphytic orchids.According to resource allocation,there are 6 dominant species,accounting for31.58% of the total species,and 7 abundant species,accounting for 36.84% of the total species;2.Compared with neighboring regions,the similarity of orchid plant genera in Inner Mongolia is greater than that of species,and there are certain differences in the composition of genera and species.The similarity with the genera and species in Hebei region is the highest,with a moderate similarity;The similarity with the Ningxia genus is the smallest,and the similarity with the species in Shaanxi region is the smallest,both of which are extremely dissimilar.3.Orchidaceae in Inner Mongolia are widely distributed but unevenly distributed.In terms of horizontal distribution,the number of orchid plant species gradually decreases from west to east,mainly concentrated in the northwest and south of the Great Xing’an Mountains,and the northern part of the Yanshan Mountains,making it the area with the highest density of orchid plant distribution.In terms of vertical distribution,as the altitude gradient increases,the species of orchid plants first increase and then decrease,mainly distributed in the middle to high altitude range(400-1600m),with the most species distributed at 400-800 m.4.There are significant differences in orchid plant species under different habitats in Inner Mongolia,and species similarity is generally low.The orchid plant species in the research area are the most abundant under climate conditions with an annual average temperature of-3-6℃ and an annual precipitation of 360-560mm;6-25° is a slope with abundant orchid plant species;Orchid plant species are most abundant on the north,east,and south slopes;The middle and upper parts are slopes with abundant orchid species;Broad leaved deciduous forest with canopy density of 40-70% and soil humus layer thickness>2cm is a community environment with rich orchid species.5.The high mountain terrain,community vegetation type(mixed coniferous and broad-leaved deciduous forests),and altitude are key habitat factors that affect the distribution of orchid plants in Inner Mongolia.Annual average temperature,slope,canopy density and soil humus layer thickness also explained the spatial variation of orchid plant community composition to some extent.Habitat factors have a significant effect on the abundance of 13 wild orchid species in both univariate and multivariate models.