Giant Tail Peak Forest Farm Planting Eucalyotus Forest Biomass Productivity And Soil Hydrological Function Research

Eucalyptus, as one of the fastest growing and spreading tree species in Southern China area, has the advantages of fast growing, high yield and so on. It is the most important raw material of paper pulp, and also the main industrial raw material of artificial board factory.The research site is located on the Guangxi State Gaofeng Forestry Farms in successive planting Eucalyptus forest land. Eucalyptus plantations were planted since March 2014, established with high density (3330 plant/hm-2) and control (1665 plant/hm-2). This study is try to reveal the growth, biomass and productivity, soil infiltration capacity and seasonal dynamic changes of soil and water conservation capacity of 2 years old Eucalyptus Plantation, in order to analyze the feasibility of high dense Eucalyptus plantation in the successive planting Eucalyptus forest land, and its potential regulation on soil moisture function, which provided theoretical basis and technical support for the eucalyptus plantation. The main results as follows:1 stand growth:The individual tree height, DBH, Volume were 9.7 m and 8.4 cm,0.02730 m3 respectively in the dense Eucalyptus plantation (DEP forest), 10.5 m,9.4 cm,0.03821 m3 respectively were in the Control density(CK). The growth in the former was slightly lower that of the later. The growth rate of tree height, DBH and volume in the DEP forest reach the maximum in the 0.5 year.2 biomass and productivity:The biomass were 58.79 t·hhm-2,38.09 t"hm-2 respectively in the 2 years old DEP and CK forests, the annual productivities were 29.40 t·hm-2·a-1,19.05 t·hm-2·a-1, The biomass, the annual productivity in the DEP forest was greater than those in the CK forest.3 The permeability of Eucalyptus Plantation Soil:The soil initial infiltration rates in the DEP and CK forests were 2.16mm/min,1.96mm/min; soil steady infiltration rate were 0.46mm/min,0.39mm/min, planting; constant total penetration rate were 29.76 cm-2,34.04 cm-2 respectively.4 The dynamics of soil water content:The DEP and CK forests showed the same soil water content dynamics, in the order of summer> winter> autumn> spring. The soil water content in the DEP forest were 33.43%、31.89%、 31.00%、29.43% respectively; The soil water content in the CK forest were 28.48%、26.67%、26.61%、26.19% respectively. In 0-40cm soil layer, the maximum soil moisture content values of DEP and CK forests both appeared in summer, the highest were in June and the lowest in April. Generally, the soil water content in the DEP forest was slightly higher than that of CK forest, due to the dense forest canopy and the slightly lower soil evaporation in the DEP forest.5 water conservation function:The soil bulk density (g/cm) in the soil layers of 0-20cm,20-40cm,40-80cm in DEP forest and CK forest were 1.29,1.400,1.52 and 1.13,1.40,1.56 respectively. The soil total porosity in the soil layers(0-20cm,20-40cm,40-80cm) were 51.34%,47.34%,42.62% in DEP forest,57.35%,47.18%,41.31% in CK forest. The 0-80cm soil maximum water storage capacity in the DEP and CK forests were 137.70 t·hm-2,126.00 t·hm-2 respectively. The 0-80 cm soil effective water storage capacity in the DEP and CK forests were 137.70t·hm-2 and 126.00t·hm-2. The ecosystem water capacity in the DEP and CK forests were 140.17 t·hm-2,127.22 t·hm-2.In a word, except the individual growth, the forest biomass and productivity, the intercept moisture, moisture permeability and the total ecosystem water conservation in the DEP forest was slightly better than those in the CK forest.