Spatial Characteristics Of Soil Chemical And Phisical Property Influenced Distribution Of Plant Diversity In Gurbantunggut Desert

Vegetation was subject for windbreak and sand-fixation, and had a close relationship between the distribution and soil properties. Soil was the main base of desert ecosystems. Under the effect of wind wave, the different soil particles were sorting. Physical and chemical properties distribution pattern forming, showed the spatial and temporal heterogeneity. Desert spatial variability of soil physical and chemical properties will be useful to realise the influence of plant diversity, the condition of mobile dunes, and wind erosion, and then analyze the distribution of plant diversity mechanism.Gurbantunggut Desert is the largest fixed and semi-fixed desert in China, the plant diversity is relatively rich in the desert, but the human activities, such as oil field exploitation, grazing, vegetation degradation, plant diversity are reducing. This article first from the soil properties spatial distribution characteristics in Gurbantunggut Desert influence on plant diversity, as well as for analyzing the characteristics of the sand dunes change, and understanding the mechanism of vegetation distribution, thus lay a foundation for the vegetation restoration.Based on the distribution of plant diversity representative Gurbantunggut Southern Desert as the research area, according to the sand dunes ups and downs, precipitation size and distance to oasis, the whole area was divided into the ancient Manas lake area, the western desert, eastern desert hinterland, desert and oasis fringe area five parts, using methods such as statistical analysis to the south, and local scale desert five partitions the spatial distribution of the physical and chemical properties, using the model in addition to the trend of correspondence analysis(DCCA) the relationship between soil physical and chemical properties and plant.In different area, soil p H, conductivity, especially decreasing sulfate from west to east and from north to south. Total nitrogen, available potassium, available phosphorus, and total phosphorus increased from west to east. The organic matter decreased from northwest to southeast and south and north sides to desert desert hinterland downward trend. Sodium ions declined from the east and west on both sides of the desert to the desert hinterland.But the total nitrogen, available potassium and organic matter had a local patch shape distribution characteristics.Soil average grain size decreased from desert northwest to the southeast of the desert.In local parts, the soil organic matter, total nitrogen, sodium ion, sulfate, available potassium and available phosphorus content increased from top to bottom. Soil organic matter content, total nitrogen, available potassium content and the content of available phosphorus were the maximum value appeared in the late east slpoe, sulfate and sodium ion content peak appeared from at the end of slpoe.Surface soil average particle size was between 90 μm and 160μm, especially significant differences in the southern oasis edge region and desert hinterland. Desert soil fractal dimension was from 1.08 to1.08, and oasis fringe fractal dimension from 1.64 to 2.48 in southern Gurbantunggut Desert.Species composition and distribution are differences in different partitions. Ancient lake area, the western desert, eastern desert hinterland, desert and oasis edge distribution respectively, 52 species, 42, 69 species, 69 species and 81 species. Species distribute in Chenopodiaceae、Asteraceae、Cruciferae、Fabaceae、Gramineae、Boraginaceae,including Haloxylon ammodendron、Salsola praecox、Ceratocarpus arenarius、Agriophyllum squarrosum、Malcolmia scorpioides、Hyalea pulchella、Alyssum desertorum、Corispermum lehmannianum、Astragalus flexus、Aristida adscensionis、Heliotropium acutiflorum、Senecio subdentatus。Clay content in different periods and plaques change were the important factor affecting the soil spatial pattern.From 2010 to 2014, soil had distinctive trend of coarsening developing at the different regions in the five years. Soil degradation degree were different from oasis to desert hinterland, the phenomenon of soil coarsening was significantly higher in oasis fringes than desert hinterland.Clay loss rate was 36% in desert hinterland, and the oasis fringes loss rate of 129%.Particulate matter quality loss contributed to the spatial pattern of soil formation.The ability of three major desert plaque(bare land, herb and brush) to prevent wind erosion was different, mainly reflecting in the change of the fractal dimension of soil. Within five years, bare soil fractal dimension reduced 0.15, herbaceous base part of the fractal dimension increased 0.28, and brush base dimension increased by 0.11.Based on block Raupach model to simulate the oasis edge of two kinds of surface wind erosion, when vegetation coverage reached maximum 35%, surface critical friction velocity of 1.44 m/s, and increased the threshold the wind blowing the sand,The critical area of bare land surface friction speed is 0.65 m/s, surface soil erosion extremely easily, it provides an important power for soil redistribution.DCCA analysis showed that the electric conductivity, the average particle size, elevation, slope and environmental factors significantly correlated to explain the species distribution. Available potassium, total nitrogen and organic matter mainly affected Koelpinia linearis, Eremosparton songoricum, Suaeda glauca, Syrenia siliculosa, Astragalus flexus;The chloride ion species mainly affected Peganum harmala、Cousinia affinis; Average particle size, slope and elevation affected Spirorhynchus sabulosus, Silene nana, Chrozophora sabulosa;Available phosphorus, total phosphorus and conductivity affected Heliotropium ellipticum、Tamarix chinensis、Alyssum desertorum、Atriplex dimorphostegia、Astragalus ammodytes.Above all, Gurbantunggut Southern Desert has obvious spatial heterogeneity of soil physical and chemical properties, mainly influenced by wind erosion, Manas lake, underground water level, and species. Species composition and distribution are very different in Each partition. Soil properties have a significant impact on plant diversity distribution, but different species are reliance on different soil properties.Desert sand clay content and plaques rendered in dynamic change.