Research On Plant Species Diversity And Soil Physical And Chemical Properties In Eucalyptus Urophylla×Eucalyptus Grandis Sprout Plantations

The study reseach in different age of E.grandis sprout forest in Guangxi state-owned slope forestry centre,as the object of study screened of 3 pieces of E.urophylla ×E.grandis spdrout forest settin,and the standard sample, to carry out dynamic monitoring of standard plot and wasteland as the control sample of E.urophylla×E.grandis sprout Forest 1 year,2 years,3 years,4 years students understory vegetation diversity survey. Simultaneous determination of stands of different age of soil physical and chemical properties, and to explore the understory vegetation diversity and soil physical and chemical properties of correlation, Guangxi state-owned slope forestry centre in different age tail E.grandis sprout forest quality assessment. The main results are as follows:(1) From 1 years old to 4 years old, Guangxi state owned seven plants of Eucalyptus sprout forest slope forest to Moraceae, Rosaceae and Gramineae, involving 38 families,56 genera and 73 species in the herb layer species richness index (Margalef index) in 1 years,2.53 in 3a. Years has continued to decline significantly, in 3 years minimum,1.32; shrub layer argalef index 2 years stand the Menhinnick (2.23) and (0.67) the highest; in different age forest, Shannon index 2 years old stands of shrub layer material (1.78) and Simpson index (0.73) was four. The highest forest herb layer evenness index (Jsw index and Jsi index) for 4 years, the value of were 0.92,0.92; The shrub layer was 2 years old, and its value was 0.81 and 0.82.(2) In different age stages of Eucalyptus sprout forest, soil water content had no significant difference, reached the maximum in fourth years is only 34.32%; Soil layer of different and deepened and improved respectively, and-for the tail of different ages in Eucalyptus grandis plantation soil moisture content change trend:0?20 cm 20?40 cm>40?60cm from the ground, and in the 0?20 cm soil layer,4 years of the soil organic matter content is barren and 1 year, respectively, to improve the 396.97% 207.43% total nitrogen content is barren,1 year 446.27%305.1. Along with the soil depth,4 years soil organic matter content is barren,1 in 20?40 cm respectively to improve the 382.19% 205.14%. age identical soil porosity, in the four years the stand top layer, soil bulk density, along with the soil depth increased with increasing.In the 0-20cm layer, soil bulk density changes overall increases with the increasing of soil depth, while the soil porosity but with soil depth showed significant decline in soil fertility analysis; in the process, found that the soil organic matter, total nitrogen, available phosphorus increased with stand growth increased; with the growth of forest stands, soil available potassium, nitrate nitrogen, ammonia nitrogen changes greatly, do not have the regularity; soil pH value difference was not significant.(3)Correlation analysis showed that the herb layer diversity index to care about the physical and chemical properties of soil and soil total nitrogen, ammonia, nitrogen, available phosphorus and soil pH value was significantly correlated; the shrub layer diversity index and soil total nitrogen content, there are significant differences in soil moisture content and soil pH value. concludes that main factors affecting species diversity of Eucalyptus plantation soil total nitrogen content and soil pH value.