The Study Of Forest Soil Environment Quality And The Plant Species Diversity Along Baotian Highway

With the development of economy, highway has become a fast channel of communication between the cities. Highway inevitably interfere the forest soil environment and vegetation with the construction. So it is of the importance to study forest soil environmental quality and protect the biodiversity along the highway, In order to study, Sun Mountain Tunnel to Maiji Mountain Tunnel along Baotian highway in Tianshui, Gansu, mainly studying the soil environment quality condition and community diversity of plants, discussing the influence of habita factors to plant biodiversity, such as soil physicochemical properties, nutrient, microbial quantity and terrain conditions. The main research conclusions are as follows:(1)Compared with the Xiaolongshan forest in Gansu province, water content of soil, organic matter and rapidly-available nitrgen of average fell respectively47.34% 、 56.08% 、 82.38% 、 36.27% along the highway. The soil p H and rapidly-available phosphorus content increase respectively 16.48% and 47.14%. Soil nutrients rise with the increase distance extend along highway. However, an opposite trend existed for p H.(2)Along the highway of different land use ways on the influence of the soil nutrient content are reached significant level. The soil moisture content of three kinds of forest is in order of: secondary forest > natural forest > plantation; p H, organic matter and rapidly-available nitrogen content are in order of: natural forest >secondary forest > plantation; Rapidly-available phosphorus is in order of: secondary forest > plantation > natural forest; Rapidly-available potassium is in order of:secondary forest > natural forest plantation > plantation.(3)Nemerow indexs shows that the soil fertility index trend –phosphorus in order of control group(2.09) > natural forest(1.50) > secondary forest(1.30) >plantation(1.12).(4)The construction and operation along the highway construction had a bad effect on the plant community of ecological. The nearer the highway ecological health of plant community is relatively worse, and different land use types of forest vegetation in performance for health is in order of :natural forest > secondary forest >plantation.(5)As for community different ways of land use, vegetation vertical hierarchy of species richness are characterized by natural forest > secondary forest > plantation.In tree layer, species diversity(Simpson), Shannon- weiner index and evenness index of Jsw and Jsi performance are all in order of : natural forest > secondary forest > plantation. In the shrub layer, species diversity(Simpson) and Shannon-weiner index performance are all in order of: the secondary forest > natural forest >plantation; Species evenness Jsw performance is in order of secondary forest >plantation > natural forests, secondary forest > evenness index of Jsi performance for natural forest > plantation. In herb layer, species diversity(Simpson), Shannon-weiner index and evenness index of Jsw and Jsi performance are all in order of :natural forest > secondary forest > plantation.(6)The results of correlation analysis shows,The plant species richness andsoil p H, organic matter, available N, longitude, altitude has highly significant positive correlation, and available K, the slope is significantly negative relevant or significant negative correlation; organic matter, available N and plant species diversity shows significant positive correlation, available potassium,slope and plant species diversity for extremely remarkable negative relevant or significant negative correlation.(7)Principle component analysis shows that the first principal component has higher load of p H, organic matter, available N, longitude, altitude, available K and slope; in the second principal component, the higher load is the water content,available phosphorus, slope, altitude, total microbial biomass and latitude; slope and elevation at the same time in the first and the second principal component have higher load.