Dynamics Of Soil Microorganism And Soil Enzyme Activities Of Various Types Of Sand Dunes In Shapotou Region

This study was carried out in the eight different artificial desert lands in Shapotou Region of Ningxia province, which include ( the dune-top of sand dune with artificial vegetation of 1956, the windward dune of sand dune with artificial vegetation of 1956, 1964, 1981; the leeward dune of sand dune with artificial vegetation of 1964 ,1981; sand dune with artificial vegetation of 1987 and 1991 ) and two different CK lands, i.e., flowing sand and Cuiliugou. This paper investigated the quantity dynamic of three major microorganism, i.e., Fungi, Actinomycetes, Bacreria and Silicate bacteria, Aerobe Arotobacter, Phosphate solubilizing bacteria, Aero-cellulose decomposing bacteria, as well as, the activity of Urease, Catalase, Phosphatase, Celluloytic enzyme, Mylase, Polyphenol-oidase, Invertase. The main results showed as below.1.The dynamic of microorganism(1) There was a great vertical distribution trend of the microorganism in different soil layer, the surface has the largest quantity of microorganism, and the quantity is decrease with the deeper blow the soil.(2) There was apparent seasonal dynamic pattern about the quantity of three major microorganism, i.e., autumn>summer>spring>winter. The three layer of the eachsampling site show apparent time difference. There was a different pattern between the microorganism community and the quantity of microorganism. In Silicate bacteria and Aerobe Arotobacter: summer>autumn>spring>winter. In Phosphate solubilizing bacteria: winter>autumn>summer>spring. In Aero-cellulose decomposing bacteri-a: summer>autumn>winter>spring.(3) The total number of microorganism varies greatly, in 2.24×106 /g dry soli~3.35×107/g dry soil, the rank is Cuiliugou>56 year windward dune>56 year dune-top>64 year windward dune>64 year leeward dune>81 year windward dune>81 year leeward dune>87 year stable desert land>91 year>flowing sand. The Bacreria's account for the majority of the quantity, which take up 82.70%~89.70% of the microorganism, Actinomycetes is the second largest microorganism, which account for 10.22%~17.20%. fungus has the smallest number, which account for 0.08%~0.11%. the total quantity of Bacreria and Actinomycetes take up 99.9% of the total microorganism.2.The main fungus colony.There were total 7 genera and 44 species in 10 sampling site, among which 10 species of Aspergillus spp., 8 species of Penicillium spp., 6 species of Fusarium spp., 1 specie of Rhizopus sp. 2 species of Mucoraceae spp.. 2 species of Trichoderma spp. 3 species of Curvularia spp. And there were 12 species of bacterial needed to be confi-rmed. Aspergillus sp and Penicillium sp take up the majority of the microorga-nism.3. The analysis of the activity of enzyme.The soil enzyme of there layers of soil (56 years of windward dune, 64 years of windward dune, 81 years windward, 91) has been reseached.(1) The activity of 6 enzyme in the soil is higher than the stable desert. There were no regular changing pattern in the 4 sampling site of the stable desert, the lowest active enzyme is Urease, while the highest activity of enzyme is Mylase and Catalase.(2)There were significant correlation between the Urease, Catalase, Phosphatase, Invertase.Except Celluloytic enzyme,Mylase, Polyphenol-oidase.(3) There were different correlation pattern between 7 enzyme and 3 microorganism. Urease, Invertase and Fungi has the positive correlation; Urease, Phosphatase, Invertaseand bacterial has the significant positive correlation; as well as Catalase and bacterials; Phosphatase and Actinomycetes also show the same relationships. Urease, Catalase, Invertase and Actinomycetes is also has the positive correlation.