| The Southern Greater Khingan Mountains was situated in the Chifeng Territory of eastern border of Inner Mongolia. As a transitional area of Mongolian plateau and Liaohe plain, it originated in Taoer river at the foot of the Northern Greater Khingan Mountains then reached Keshiketeng banner and hardwoods in Northern Yanshan Mountain. Extensive communication and differentiation were common in this area with unique geographic position. During1980’s, Bryological investigation was carried out successively by Prof. Bai et.al. in several nature reserves of the Southern Greater Khingan Mountains, such as Huanggangliang, Saihanwula, Dalengshan, Bayan-Ovoo, Gaogesitai. Data about part of the area has been documented in the "Flora Bryophytarum Intramongolicarum". There were collections of ca.2300bryophytes specimens including original herbarium data and new supplemental collections from subsequent systematic surveys into Saihanwula (2007), Huanggangliang (2010) and Wulanba-shipenggou (2011) of this area.A total of314species, including1subspecies,15variants,2forma in130genera and49families were reported. Of these,39species, belonging to22genera in17families, were liverworts. While275species,108genera in32families were mosses. The bryophytes of this area take up61.45%of the species, the genus take up70.65%of the genus,77.78%of the family in that of Inner Mongolia. Mosses in this area account for larger proportion than liverworts in both quantity and variety. The bryodiversity was effectively retained in the6nature reserves. However, due to physiological adaptations to the climate and the geographic conditions, significant difference of bryophyte composition and diversity were existed among the6region. As a representative area, Saihanwula Nature Reserve was rich in bryophytes account for44families,111genera and222species; there were39families,86genera and181species in Wulanba-shipenggou Nature Reserve;39families,92genera and158species in Dalengshan Nature Reserve;32families,64genera and107species in Huanggangliang Nature Reserve;35families,71genera and132species in Gaogesitai Nature Reserve. And13families,24genera and36species were collected from arid, infertile and desertificated Bayan ovoo Nature Reserve.The study showed that there were12dominant families (24.49%), including72genera (55.38%) and224species (71.34%);12dominant genera (9.23%) taking up32.80%species of the study area where abound in single-species families and2-3-species families. The whole area was rich in bryophyte families and genera, then relatively poor in species number. Most species and genera were included in the few dominant families and dominant genera. Above statistics reflected the of complex bryoflora of the central Asian steppe and arid desert region. Our conclusion was consistent with the flora of vascular plants. Besides the dominant family and genera could mirror the characteristic of natural geo-climatic conditions. Such as drought-resistant Pottiaceae was the first dominant family which reflected the drier climate than moist of this area; As the representative families in the North China Region, Brachytheciaceae, Mniaceae and Thuidiaceae were dominant which reflected the flora of North China of this area; Grimmiaceae spread over the rocks, representing the drought rocky microenvironment; wide distribution of acquatic Amblystegiaceae and epixylous Orthotrichaceae reflected the rich humid epixylous habitats in ancient woodlands of this area; the dominance of Frullaniaceae typically distributed in East Asia Region and Dicranaceae typically distributed in boreal cold coniferous forests explained the continuity and similarity with the Northern Yanshan Mountains and the Northern Greater Khingan Mountains respectively.The following5species of this area were new to China:Didymodon zanderi Afonina&Ignatova., Didymodon hedysariformis T. Otn., Homomallium adnatum (Hedw.), Broth. Schistidium lancifolium (Kindb.) Blom., Grimmia longirostris Hook.. The family Claveaceae and the genus Clevea in the checklist were new to Inner Mongolia; and12species were new to Inner Mongolia:Plagiochila duthiana Steph., Frullania hamatiloba Steph., Frullania parvistipula Steph., Apometzgeria pubescens (Schrank.) Kuwah., Clevea pusilla (Stephani) Rubasinghe, Sumudu C. K.&D.G. Long, Syntrichia amphidiacea (Mull. Hal.) R.H. Zander, Barbula convoluta Hedw., Rhodobryum ontariense (Kindb.) Paris, Thuidium philibertii Limpr., Podperaea krylovii (Podp.) Iwats. et Glime., Climacium japonicum (Lindb.) Press., Pogonatum proliferum (Griff.) Mitt. Several species were newly extended their distribution range to the Southern Greater Khingan Mountains, such as Trocholejeunea sandvicensis (Gott.) Mizut., Porella gracillima Mitt., Grimmia incurva Schwaegr., Plagiomnium succulentum (Mitt.) T. Kop., Aulacomnium palustre (Hedw.) Schwaegr., Timmia bavaria Hessl., Polytrichum juniperinum Hedw. etc. Therefore, these new records were new addition to the bryoflora of China, and the discovery of these bryophytes by this study in new geographic regions was considered a noteworthy extension of their local distribution range. A checklist and keys to all identified taxa were provided. In addition, ca.120taxa were photographically documented.The floristic geographic elments were studied, temperate elements (account for61.94%) play an dominant role in this area, accompanied with East Asian elements (account for16.42%). Other floristic elements were also existed. As a crossing of a series of transitional area, different floristic elements were gathered together in this area.Compared with the other9studied mountains, the result of species similarity index was basically in line with the analysis of the euclidean distance between species dissimilarity coefficient index. The statistics showed that the Southern Greater Khingan Mountains was the most significantly related to the Northern Greater Khingan Mountains and the Northern Yanshan Mountains, and the more significantly related to Daqingshan Mountain and Helanshan Mountain; behaved low similarity with Eastern Tianshan Moutain of the Tibetan area and Altai Mountain of Inner Mongolia-Xinjiang region, Changbaishan Mountain and Taibaishan Mountain of North-eastern China; while irrelevant with Xitianmushan Mountain. To some extent, the Cluster Analysis of10mountains reflected the relationship of the geographic distribution, longitude and latitude, the geological geomorphology, climate zone and the bryodiversity flora.The analysis of habitat diversity index indicated that the bryophytes composition in eight kinds of habitat decrease in the following order:Wet soil, Wet rock, Mixed forest, Arid rock, Arid soil, Epixylous, Picea forest, Aquatic; species dominant differences were exited in the8habitats. Based on the a diversity indexes, it was found that the variation trend of species richness and species diversity were similar in8typical habitats, arranging as following order:on moist soil, on moist rock, in mixed forest, on dry rock, on dry soil, in picea forest, aquatic habitat, epixylous habitat. Species dominance index and community evenness index were low and varied within a small range in8habtats, valuing less then1, indicated that both species dominance and community evenness were relatively low. In other words, the bryophytes composition the dominant species were quite different in8kinds of habitat, bryophyte community distributed unevenly in vegetation. However, bryomass was larger than vascular plants in ecosystem of moist forests. Consuming less energy, bryophytes could preemptively occupy the habitats that other plants cannot grow. And bryophytes crust kept sands stable. The changes of the habitat conditions played an important role on bryophyte diversity.The Southern Greater Khingan Mountains was lying on the crossing of East China region, Northeast China region, Inner Mongolia-Xinjiang region; as a transitional zone between steppe and forests, it delimitated the boundary of coniferous forest and broad leaved forest. Consequently a gradual transition of the rich bryoflora was produced in this area. Compared to the Northern YanShan Mountains and the Northern Greater Khingan Mountains, forest density and humidity of this region was lower, so large-sized ground bryophytes vegetation layer was not common and unstable in this area, bryophyte species were relatively poor. Therefore, the environmental quality of forests were unstable due to the serious degeneration of the forests environment and human activities. Suggestions for futher conservation of transitional ecosystem among grasslands and forests were put forward in this paper. Then, more nature reserves should be able to protect rare and endangered species and more wildlife groups in this area. |
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