Growth Characteristics And Evaluation Comprehensive Benefits Of The Acacia Mangium Plantation

In the 21st century,the environment and the development are remaining the two major themes of development in the world.It is the human pursuing goal to improve the welfare of human life.Forest has been playing an irreplaceable role in environmental protection and economic development.In recent decades,as China's rapid economic development,improving people's living standards and the rapid population increase,which made the growing demand for forest products exceed the timber supply.For a long time,to protect our fragile ecological environment,our country has spent a great deal of foreign exchange in importing forest products.After the Ecological Forest's commodity production function was strictly limited,the development of short-period plantation,which was not only the growing needs of the community,but also was an effective way to protect the ecological environment.At present almost all short-period plantations of the South are eucalyptus plantations,but the large area of any single species and continuos planting is generally easy to cause forest soil fertility decline,reduction in biodiversity,and other issues.Therefore,to improve the structure of a single species, the construction of harmonious ecological system of the multi-species plantations, which has a great significance.Acacia mangium species,with wide adaptability,high recovery ratio,widespread use and has the advantages of soil improvement and nitrogen fixation.In recent years,in the southern plantation construction,Acacia mangium plantation has made a rapid development and has a significant ecological and economic benefit.However,Acacia mangium plantation in the South is still a very small percentage of the plantation.Therefore,in order to improve the ecological structural system of the South of China plantations,it is very important that using economic means to evaluate the comprehensive benefits of the Acacia mangium plantation.The study has used the market value method,the shadow engineering method, the comparative analysis method,and other evaluation methods,to study the comprehensive benefits of Acacia mangium stand,the results of the study could be showed as the following aspects:(1)The growth characteristics of Acacia mangium stand.The forest biomass,the tree height of forest tree layer,the DBH and the volume of Acacia mangium stand grew with the age increase.The trunk wood of the forest biomass was the highest proportion,it also grew with the increase of forest age.Before the 4th year,Acacia mangium Stand prior to the nutrition growth,then gradually to reproductive growth.(2)The economic benefit of Acacia mangium stand.The economic benefit on the project of per hectare area Acacia mangium stand showed that:The average profit of investment rate of the Acacia mangium forest project was 11.5%,the average annual investment rate of profit-tax was 12.8%,the financial internal rate of return was 22.4%,the financial net present value was￥2375.3,dynamic investment payback period was 5.7 years,the investment recovery period was shorter,the risk of project was small.(3)The comprehensive benefits of Acacia mangium Stand.The 6-year-old Acacia mangium stand,it's ecological benefit was 17452.6 yuan·hm^-2,it's social benefit was 8739.9 yuan·hm^-2,it's comprehensive benefits was 30499.5yuan·hm^-2.