Study On Plant And Soil Characteristics Of Two Differen Plantations In Steppe Region Of Ulanqab

This study was done at state-owned forest in Tumuertai town,Chahaeryouyihouqi, Ulanqab city of Inner Mongolia,from 2007.10-2008.9. Different types of plantations of different densities and vegetation characteristics of soil properties analyzed,the main research results are as follows:(1) Plantation made the soil quality decreased; inner forest better than the forest edge in herb diversity, but compared with the grass, only Populus simonii has significant difference. Physical properties of soil, the poplar with fine clay content in the soil increases the soil bulk density of poplar with the outer edge increases,and the growing rate is 8.84%. Low-density elm forest soil moisture content was significantly lower than poplar, and the decreasing range is 28.42%. Elm forests of high-density and control the quality of grassland soil moisture content, which reduces the soil moisture content. Chemical properties of soil, the growth of Populus simonii decreased the soil organic matter, and the decreasing range is 43.80% .Low-density Ulmus pumila elm and the outer edge of Populus simonii made the soil PH value increased, and the growing rate is 2.8% and 2.4%. Phosphorus and potassium content is relatively significant only potassium,nitrogen and phosphorus are in the region of non-cultivated soil nutrient content in a lower level.(2)Changes in plant characteristics between subjects in the trial area is a big difference,but on the whole,the height of high-density Ulmus pumila is most , density is minimum; high-density Ulmus pumila and the open space between Elm has the greatest coverage; important value is the maximum in Populus simonii; biomass is the maximum in low-density Ulmus pumila.(3) The experimental area has a different diversity index, but the overall trend is consistent, that is the forest> grassland> forest edge (except Species Richness in area of E). Inner forest was significantly higher than outside the forest in Equitability index, edge of Populus simonii was significantly lower than the grass; Edge of Populus simonii was significantly lower than the inner forest and grassland in diversity index; richness index, Inner Populus simonii was significantly higher than the other experimental area (except high-density Ulmus pumila).