Giant Tail Eucalyptus Industrial Raw Material Forest Biomass

Thirty-one pieces of Eucalypts grandis×Eucalypts urophylla and its comparison plots have been selected in Pu'er city.Based on the surveys of mean trees,the biomass and productivity of 4-year old Eucalypts grandisxEucalypts urophylla are studied;the comparative analysis for understory vegetation biomasses between Eucalypts grandis×Eucalypts urophylla and the same conditions of 7 neighbouring comparison plots; analyzing the relativities of understory vegetation biomasses of Eucalypts grandis×Eucalypts urophylla and climate,environmental factors by SPSS statistical software.Study on the above-ground biomass and productivity and four regression models which include the parameter of biomass,diameter and height with equations W=a(D~2H)~b, W=a+bD+cD~2,W=a+bD,W=aD~b are built up.The results show:(1)Total biomasses of understory vegetation of 7 investigation points of Eucalypts grandis×Eucalypts urophylla are been compared,following the order:Songshanlin＞Caiyanghe＞Dongzu＞Mifengyan＞Laobandeng＞Dapingzhang＞Nanling,total biomasses of understory vegetation of Eucalypts grandis×Eucalypts urophylla with different soil types are been compared,following the order:yellow soil＞red soil＞brown soil＞latedte soil＞red brown soil＞purple soil＞yellow brown earth.The biomass of understory vegetation herb layer is more than shrub layer.(2)In the relative analysises of understory vegetation biomasses of Eucalypts grandis×Eucalypts urophylla and climate,environmental factors,The results showed:the scope of average rainfall in 1524.2-2000mm,soil moisture content in 10.53%—18.52%, organic matter content in 9.25—18.060.M%,N,P,K of available nutrients content in 38.59—219.90mg/kg,0.90—1.97mg/kg,164.05—311.93mg/kg,that indicates there is no relationship between them.(3)The comparative study on understory vegetation biomasses between Eucalypts grandis×Eucalypts urophylla and other eighbouring Pinus kesiya var.langbianensis with the same conditions,knowing:understory vegetation biomasses of Pinus kesiya var. langbianensis＞understory vegetation biomasses of Eucalypts grandis×Eucalypts urophylla, the proportion of understory herb layer biomasses of Eucalypts grandis×Eucalypts urophylla＞the proportion of understory herb layer biomasses of Pinus kesiya var. langbianensis,the proportion of understory shrub layer biomasses of Pinus kesiya var. langbianensis＞the proportion of understory shrub layer biomasses of Eucalypts grandis×Eucalypts urophylla.(4)The biomass of mean tree and its distribution of above-ground tissues are arranged in the order of bole＞bark＞branch＞leaf.The larger density,the smaller above-ground biomass of mean tree.The tissue productivity is arranged in the order of bole＞bark＞branch＞leaf.(5)Biomasses(kg)distribution of above-ground tissues of the Eucalypts grandis×Eucalypts urophylla as a result of variable diameter(cm),height(m)as the independent variables,the biomass estimation model with equations W=a(D~2H)~b, W=a+bD+cD~2,W=a+bD,W=aD~b are built up to regression analysis.The minimum of the regression correlation coefficient of biomasses distribution of above-ground tissues of the Eucalypts grandis×Eucalypts urophylla is 0.7955(regression correlation coefficient of leaf). Other correlation coefficients are more than 0.8,it shows that the configuration of the regression equation have reached significant levels.So they can be used to be as the biomass estimation model of Eucalypts grandis×Eucalypts urophylla.As to the practice,the equitation W=a(D~2H)~b is better than the others in Pu'er city.