Study On The Bryoflora And Its Distribution Characteristics In Daqinggou National Nature Reserve

Daqinggou National Nature Reserve is the center for biodiversity in the southeast of Horqin sandland,and is also the precious natural heritage.Bryophtes are widely distributed in various vegetations in this area,and havesignificantfunction on conservation of water and soil and keeping the stability of ecosystem.Based on the general specimen collection in the area of Sanchakou and Xiaoqinghu,in-depth collection in core area and sample-plot survey of 5 main vegetation types in whole study area,the bryoflora of community of Daqinggou and its distribution characteristics were systematicly studied.The main conclusions as follows:(1)23 families?55 genera?118 species of bryophytes(including subspecies and varieties)were discovered in Daqinggou National Nature Reserve.7 families?9 genera?15 species of livereorts and 16 families?46 genera?103 species of mosses(including subspecies and varieties)were among them.The total of families,genera and species of bryophytes in this area respectively occupied 36.51%,29.89%and 23.09%of the total number of bryophytes in Inner Mongolia.It was the most concentrated distribution area of bryophytes among sandy vegetation in China.The dominant family were Pottiaceae?Brachytheciaceae?Bryaceae?Amblystegiaceae?Mniaceae et al.The dominant genera were Brachythecium?Bryum?Frullania?Plagiomnium?Campylium?Entodon et al.48 species were newly found in this research area.It's obviously enriched the research findings of bryoflora in this area.there are 5 kinds of life-forms including Toll Turfs?Short Turfs?Mats?Weft?Slanting,which respectively occupied 7.63%?37.29%?12.71%?39.83%?2.54%of total number.(2)118 species of bryophytes in the nature reserve belong to 9 kinds of floristic geographical elements types,including North Temperate(64 species,54.24%),East Asia(23 species,19.49%),Cosmopolitan(15 species,12.71%),Endemic to China(5 species,4.24%),Temperate Asian elements(3 species,2.54%),Pantropical elements(2 species,1.69%),Tropical Asian-African elements(2 species,1.69%),Asian and North American elements(2 species,1.69%)and Old World Temperate elements(2 species,1.69%).Floristic composition was diverse and complex,and shows a typical temperate climate characteristic and obvious characteristics of East Asia.(3)24 species in 11 families and 13 genera of bryophytes grew on trunk.The dominant species were Frullania muscicola?Venturiella sinensis?Anomodon minor?Anomodon minor ssp.integerrimus?Entodon compressus var.zikaiwiensis et al.(4)The result of the consequences of x2 test and correlation index was consistent.No species was significant association in Leymus chinensis community and Ulmus macrocarpa forest.1 pair of species was extremely significant positive association,and 2 pairs of species were significant positive association in Prunus sibirica shrub.4 pairs of species were extremely significant positive association,1 pair of species was significant positive association,and 1 pair of species was extremely significant negative association in Quercus mongolica forest.1 pair of species was significant positive association,2 pairs of species were extremely significant positive association,3 pairs of species were significant negative association,and 1 pair of species was extremely significant negative associationin Fraxinus mandschuria forests.The interspecific association analysis preliminary show that the similarity and differences of resource utilization and habitat adaptability of bryophytes and the diversity of micro-habitat variation of different vegetation types in different sample area.(5)Among the 5 kinds of plots of Leymus chinensis community,Prunus sibirica shrub,Ulmus macrocarpa forest,Quercus mongolica forest and Fraxinus mandschuria forest,there were 6,18,19,27,29 species repectively.Shannon-Wiener diversity exponent was between 0.9774-2.2663,and the order of the index was as follows:Fraxinus mandschuria forest>Quercus mongolica forest>Ulmus Wmacrocapa forest>Leymus chinensis community>Prunus sibirica shrub.Simpson exponent varied from 0.1316 to 0.2955,and the order was as follows:Prunus sibirica shrub>Leymus chinensis community>Ulmus macrocapa forest>Quercus mongolica forest>Fraxinus mandschuria forest.Pielou exponent of degree of homogeneity was between 0.3382-0.6730,and the order was as follows:Fraxinus mandschuria forest>Leymus chinensis community>Quercus mongolica forest>Ulmus macrocapa forest>Prunus sibirica shrub.The highest Sprenson similarity exponent of 0.6522 existed between Ulmus macrocapa forestand Quercus mongolica forest,and there was no similarity between Leymus chinensis community and Fraxinus mandschuria forest.(6)Based on the Two-way indicator species analysis(TWINSPAN)and the trend of Detrended Correspondence Analysis(DCA),32 sample-plots areas could be divided into 5 groups,which were Bryum bicolour-Weissia controversa community distributed in Leymus chinensis community,Mannia sibirica-Mannia triandra + Weissia controversa + Entodon compressus community distributed in Prunus sibirica shrub,Entodon compressus var.zikaiwiens is-Entodon compressus + Reboulia hemisphaerica + Timmiella anomala community distributed in Ulmus macrocarpa forest,Brachythecium velutinum-Taxiphyllum taxirameum + Plagiomnium cuspidatum-Timmiella anomala + Reboulia hemisphaerica community distributed in Quercus mongolica forest and Marchantia polymorpha + Leptodictyum humile-Taxiphyllum taxirameum-Amblystegium serpens + Mnium laevinerve-Plagiomnium cuspidatum-Bryum cirrhatum community distributed in Fraxinus mandschurica forest.The CCA shows that the important environmental factors of influencing distribution of community and species of bryophytes were soil water content,canopy coverage,air humidity and litter coverage.