Determination And Analysis Of Wood Density And Calorific Value Of Five Varieties Of Robinia Pseudoacacia L.Such As ‘Duocai Qingshan'

With the depletion of fossil fuels such as oil and coal,countries around the world have begun to pay attention to research on renewable biomass energy.Fuel-type energy forest is an important part of biomass energy,it is the foundation for developing biomass energy.Cultivating energy forest is an effective way to solve future energy crisis,improve ecological environment and realize energy sustainable development.Because of its advantages of strong adaptability,fast growth,easy propagation,and resistance to burning,it has been recognized as a good fuel-type energy tree species at home and abroad.In this paper,the8-year-old Robinia pseudoacacia L.new varieties in state-owned Mount Daqing forest farm of Feixian County,Shandong Province is a research object,with Robinia pseudoacacia‘Duocai Qingshan',Robinia pseudoacacia‘Ziyan Qingshan',Robinia pseudoacacia‘Zhuangmei Qingshan',Robinia pseudoacacia‘Lvman Qingshan'and Robinia pseudoacacia‘Luci10'?CK?.Through the investigation of the growth and biomass of aerial parts of each variety,the calculation of the volume of each variety,the determination of the density of various varieties of wood,and the determination of dry mass calorific value,the following conclusions have been reached:?1?The five Robinia pseudoacacia L.varieties with the same site conditions and the same tree age,with the largest amount of high growth was the Robinia pseudoacacia‘Duocai Qingshan'with an average of 12.43m,the largest crude growth volume was the Robinia pseudoacacia‘Zhuangmei Qingshan'with an average breast diameter of 18.6cm,The smallest amount of growth is the Robinia pseudoacacia‘Luci 10'.?2?The dry biomass energy of the five Robinia pseudoacacia L.varieties branches was between 58.40kg¹32.89kg,among them the largest was the Robinia pseudoacacia‘Zhuangmei Qingshan'with an average of 132.89kg.The dry biomass energy of stems among all varieties was ranked as Robinia pseudoacacia‘Zhuangmei Qingshan'>Robinia pseudoacacia‘Duocai Qingshan'>Robinia pseudoacacia‘Lvman Qingshan'>Robinia pseudoacacia‘Ziyan Qingshan'>Robinia pseudoacacia‘Luci 10'.?3?The volume of the five Robinia pseudoacacia L.varieties is between 0.0431⁰.1267m³,with the largest volume was the Robinia pseudoacacia‘Duocai Qingshan',among the five varieties,the volume from large to small:Robinia pseudoacacia‘Duocai Qingshan'>Robinia pseudoacacia‘Zhuangmei Qingshan'>Robinia pseudoacacia‘Ziyan Qingshan'>Robinia pseudoacacia‘Lvman Qingshan'>Robinia pseudoacacia‘Luci 10'.?4?The air dry density of five Robinia pseudoacacia L.varieties was between0.669⁰.786g/cm³,the basic density varieties was between0.583⁰.679g/cm³,with the largest was the Robinia pseudoacacia‘Duocai Qingshan',and the order of among the varieties was:Robinia pseudoacacia‘Duocai Qingshan'>Robinia pseudoacacia‘Ziyan Qingshan'>Robinia pseudoacacia‘Luci10'>Robinia pseudoacacia‘Zhuangmei Qingshan'>Robinia pseudoacacia‘Lvman Qingshan'.?5?The calorific value of the unit dry mass per plant of the five Robinia pseudoacacia L.species ranged from18.01¹9.18 kJ·g^-1,among them the highest caloric value was the Robinia pseudoacacia‘Duocai Qingshan',the calorific value of dry mass per plant among the varieties was ranked as Robinia pseudoacacia‘Duocai Qingshan'>Robinia pseudoacacia‘Zhuangmei Qingshan'>Robinia pseudoacacia‘Ziyan Qingshan'>Robinia pseudoacacia‘Luci 10'>Robinia pseudoacacia‘Lvman Qingshan'.?6?The results of determination of calorific value of unit dry weight of each organ of five Robinia pseudoacacia L.varieties were as follows:The calorific value of trunk dry weight was 18.06¹8.88kJ·g^-1,the tree branches unit dry weight calorific value between18.46¹8.16kJ·g^-1,the bark unit dry mass calorific value between 17.32¹8.68kJ·g^-1,with the highest calorific value was the Robinia pseudoacacia‘Duocai Qingshan';the unit dry mass of leaves was between 19.36¹9.86kJ·g^-1,with the highest calorific value was the Robinia pseudoacacia‘Zhuangmei Qingshan'.?7?The results of the calorific value of the unit dry mass of each part of the trunks of the five Robinia pseudoacacia L.species was determined as follows:the calorific value of dry mass at the base of the trunk was between 18.02¹9.07 kJ·g^-1,the unit dry mass calorific value of tree trunk chest height between 18.01¹9.18kJ·g^-1,the unit dry mass calorific value of 1/3trunk was between 18.15¹9.07kJ·g^-1,the unit dry mass calorific value of 1/2 trunk was between 17.91¹9.02kJ·g^-1,with the highest calorific value was Robinia pseudoacacia‘Duocai Qingshan',the unit dry mass calorific value of 3/4 trunk was between17.61¹8.29kJ·g^-1,with the highest value was the Robinia pseudoacacia‘Zhuangmei Qingshan';The calorific value of unit dry weight in each part of the trunk of the five Robinia pseudoacacia L.species was the highest in the 1/3 part of the trunk,which was 18.18kJ.g^-1,with the lowest calorific value of dry mass in the 3/4 part of the trunk was 18.01kJ.g^-1.?8?The calorific value of the stem dry weight of the five Robinia pseudoacacia L.varieties ranged from 1066.71²481.86 MJ,with the largest was the Robinia pseudoacacia‘Zhuangmei Qingshan',and the trend of the calorific value of the dry weight of individual stems from high to low was the Robinia pseudoacacia‘Zhuangmei Qingshan'>Robinia pseudoacacia‘Duocai Qingshan'>Robinia pseudoacacia‘Lvman Qingshan'>Robinia pseudoacacia‘Ziyan Qingshan'>Robinia pseudoacacia‘Luci 10',by variance analysis,there was no significant difference in the calorific value of the stem dry mass between the Robinia pseudoacacia‘Zhuangmei Qingshan'and Robinia pseudoacacia‘Duocai Qingshan'.?9?In this experiment,through the investigation and calculation of the biomass and volume of five Robinia pseudoacacia L.cultivars,and the measurement and analysis of the calorific value,the conclusions are drawn:in the five species,Robinia pseudoacacia‘Zhuangmei Qingshan'and Robinia pseudoacacia‘Duocai Qingshan'was larger biomass,respectively,132.89kg,124.51kg;larger wood volume with single plant was Robinia pseudoacacia‘Duocai Qingshan'and Robinia pseudoacacia‘Zhuangmei Qingshan',respectively,0.1267m³,0.1037m³;the highest unit dry mass calorific value was Robinia pseudoacacia‘Duocai Qingshan',followed by Robinia pseudoacacia‘Zhuangmei Qingshan',respectively,19.18kJ.g^-1,18.96kJ.g^-1;the highest total calorific value per plant was Robinia pseudoacacia‘Zhuangmei Qingshan',followed by Robinia pseudoacacia‘Duocai Qingshan',respectively,2481.86MJ,2343.57MJ.The Robinia pseudoacacia‘Zhuangmei Qingshan'and Robinia pseudoacacia‘Duocai Qingshan'have obvious characteristics of large biomass,large volume,and high calorific value,and are suitable for the cultivation of new varieties of fast-growing energy forests.