Study On The Bryoflra And Ecology Of Hunshandak Sandland

Through a systematic study on more than 500 bryophyte specimens collected in 2005 and2006, 26 families, 69 genera and 121 species (including subspecies and varieties) of bryophytesare found in Hunshandak Sandland, and which respectively occupy 39.68%, 36.41% and23.68% of the total number of the bryophytes in Inner Mongolia. Among them, 5 families,together with their 6 genera and 8 species, belong to Hepaticae; 21 families, together with their63 genera and 113 species, belong to Musci.Bryum kunzei Hoppe et Hornsch and Pterygoneurum kozlovii are newly recorded in China.3 species are new in the Inner Mongolia Autonomous Region, They are Desmatodon latifolius(Hedw.) Brid., Rhynchostegium pallenticaule C.Muell. and Struckia argentata (Mitt.) C.Mull.ssp. zerovii (Lazarenko) Tan.The five sandlands (desert) in and around Inner Mongolia include the maintype ofsandlands (desert) from the forest area to the forest-steppe area, the forest-steppe area to thegrassland and then the grassland to the desert. There are 26 families, 69 genera and 121 speciesin Hunshandak Sandland, 17 families, 38 genera and 68 species in Horqin Sandland, 4 families,8 genera and 11 species in Mu Us Sandland, 4 families, 11 genera and 21 species in HobqDesert and 2 families, 10 genera and 22 species in Shapotou region of the Tengger Desert. Thequantities of families, genera and species in Hunshandak sandland are obviously higher thanthe other four sandlands. The generic and specific similarity coefficient between HunshandakSandland and Horqin Sandland is the highest, and they are 37.7% and 36.5%.This opinion isprobed by the Principal Component Analysis on the species percentage of each families.The whole research area has 10 types of bryoflora compositions, which including thepercentage, are listed as follows: 22 species of Cosmopolitan (18.18%), 1 species ofPantropical elements (0.83%), 2 species of Tropical Asian-African elements (1.65%), 68species of North Temperate elements (56.20%),1 species of Asian and North American elements(0.83%), 1 species of Old World Temperate elements(0.83%), 4 species ofTemperate Asian elements(3.31%), 19 species of East Asia elements (15.7%), 4 species ofEndemic to China elements(3.31%) and 1 species of Xilinguole Typical Grassland of InnerMongolia Pantropical elements(0.83%).In ten typical habitats where exist bryophytes in Hunshandak Sandland, there are 8families, 9 genera and 17 species on the surface of sand dunes, 12 families, 27 genera and 41species at the bottom of sand dunes and lowlands between dunes, 13 families, 19 genera and27 species on sand dunes with Ulmus pumila, 16 families, 42 genera and 61 species in theblocks of woods of Betula, 7 families, 10 genera and 17 species under the bosks on sanddunes, 9 families, 14 genera and 16 species on the sandy grasslands, 10 families, 17 generaand 23 species in the marshes between sand dunes, 10 families, 17 genera and 27 speciesunder the forest of Populus and Quercus mongolica, 16 families, 32 genera and 46 speciesunder the forest of Picea meyery and 7 families, 14 genera and 18 species on the surface ofstones.By statisical comparison, the Shannon-Wiener index of bryophytes is various among theabove typical habitats. It is arranged from high to low as following: the blocks of woods ofBetula＞the bottom of sand dunes and lowlands between dunes＞sand dunes with Ulmuspumila＞the forest of Picea meyery＞the forest of Populus and Quercus mongolica＞themarshes between sand dunes＞the bosks on sand dunes＞the sandy grasslands＞the surfaceof sand dunes. The index of forest habitats is obviously higher than that of other habitatsexcept the bottom of sand dunes and lowlands between dunes. The result is mainly attributedto the water component. And the dry weather is prevalent in sandland, so it is determinedthat water is the limit component which determined the distributing region of bryophytes.By statistical calculation, 14 families, 30 genera and 48 species of bryophytes are foundin soil crust in the research region. Among them, 2 families, together with their 2 genera and 2species, belong to Hepaticae; 12 families, together with their 28 genera and 46 species, belongto Musci. Music is the main component in soil crust. The families which include richspecies are Pottiaceae(10 genera and 12 species),Bryaceae(1 genera and 11species), Hypnaceae(4 genera and 5 species) and Ambystegiaceae (4 genera and 6 species).Thenumber of bryophytes of Bryum is 11,which is the most of them. The cover degree and biomass of the soil crusts of mosses are different along with the difference of mosses and theirenvironment.By researching it is found that the content of 0.01-0.05mm soil grain in soil crust withoutbryophytes is low, but high in soil crust with bryophytes. And the former is 2.83% in average,and the latter is 21.64% in average. Although the content of 0.005-0.01mm soil grain is low atlarge, the content of 0.005-0.01mm soil grain in soil crust with bryophytes is higher than thatin soil crust without bryophytes. And the former is 2.36% in average, and the latter is 0.83%in average. Through comparing it is found that the soil crust with bryophytes can cumulate thesoil grain of 0.01-0.05mm and 0.005-0.01mm in certain degree.In soil with crust, the propotion of the grain of 0.25-1.0mm, 0.05-0.25mm and0.01-0.05mm is higher than that of the others, so they are the main components in soil.Through researching, it is found that Didymodon, Aloina and Tortula are the main componenton loess, Bryum and Pterygoneurum aer the main component on sandy soil, Bryum,Didymodon and Syntrichia are the main component on sandy soil of fixed dunes. Bryum isadapted to all kinds of grain size, and is the dominant species to make of soil crust.By studying the relation between physics and chemistry nature and soil crust, the resultimplyed entire N, entire P, fast N, fast P, the organic matter, content and soluble exchange ionof the soil with crust are higher than obviously the soil without crust, explained the soil crusthas the obvious function to accumulate trophic element. The content of N and K~+ of soil crustof Hunshandak Sandland is higher than that of the loess area of Erdos, but the content oforganic matter, P and the other soluble ions of the loess area of Erdos is higher than that ofsoil crust Of Hunshandak Sandland. The diversity between different areas results in thediversity of physics and chemistry nature, and in a certain degree, the soil crust also reacts onthe environment.