Studies On Taxonomy And Flora Of Bryophytes In Grassland Area Of Mongolia

The Mongolia is located in the hinterland of Eurasian continent,adjacent to Russia,and the East,South and West are bordering on China.The climate is dry and cold,and the ecological environment is diverse and fragile.The related research of mountain and bryophyte has attracted much attention,and the relationship between the large scale grassland and moss vegetation is usually neglected.The purpose of this study is to set up the survey line of grassland in Mongolia steppe by using different drying gradients,using the method of morphological data to explore the classification and bryoflora in grassland area of Mongolia.The main results are as follows:More than 450 bryophytes specimens has been collected from Mongolia steppe,a total of 66 species in 37 genera and 18 families were reported,liverworts have not been found.In this paper,the classified retrieval tables of families,genera and species are listed.The key features,specimen citation and micromorphologic anatomic maps are introduced in each group.1 genera was new record in Mongolia:Anoectangium,10 species were new records in Mongolia:Orthotrichum hallhi?Dicranella liliputana?Brachythecium populeum?Pohlia lescurian?Bryum leucophylloides?Anoectangium aestivum?Anoectangium thomsonii?Bryoerythrophyllum rubrum var.minus?Bryoerythrophyllum brachystegium?Tortula yuennanensis.The results of species composition analysis showed that there were 5 dominant families in this area,which were Pottiaceae?Bryaceae?Hypnaceae?Amblystegiaceae and Grimmiaceae.The 5 dominant families had 46 species,accounting for 27.78%of total families and 69.70%of total species.The floristic geographic elements were studied,north temperate elements(account for 49.30%),accompanied with Cosmopolitan(account for 30.99%).North Temperate Southern extension elements was the least(account for 3.03%).Compared with other five areas of China(included Daqingshan Mountain?Helanshan Mountain?Southern Greater Khingan Mountains?Nouthern mountains of Hebei?Easter Tianshan Mountain of the Tibetan area)The statistics showed that the researched area was the most significantly related to the Daqingshan Mountain and Helanshan mountain;behaved low similarity with Southern Greater Khingan Mountains and Nouthern mountains of Hebei;while irrelevant with Easter Tianshan Mountain of the Tibetan area.Habitat diversity analysis showed that species in different habitats were arranged as follows:soil habitats>rock and soil habitats>sock gap and soil habitats>wet land and habitats>rotten wood habitats.And the dominant species in different habitats are different.In different environments,Ceratodon purpureus,Bryum argenteum,and Funaria hygrometrica have strong adaptability.In the study area,the bryophytes of different steppe types were investigated.According to the dominant species in different steppe types,bryophyte communities were named:Bryum argenteum,Ceratodon purpureus?Grimmia longirostris,Amblystegium serpens?Brachythecium albicans.According to the principal component analysis(PCA)from the 22 western sample and the 20 eastern sample,compared to the altitude?the coverage of lichen?the coverage of litter,the dyness gradient?the coverage of herbaceous plant?the coverage of bare land and the coverage of stone and gravel were more important to the distribution of the bryophytes.