Research On Growth And Yield Model Of Betula Albo-sinensis Secondary Forest On The Southern Slope Of Qinling Mountains

Forest resources has many ecological functions, such as purify the atmosphere, fixing carbon and releasing oxygen, water conservation, sand-fixing, conservation of biological diversity and so on. In the meantime, provides material and energy for humans to live, it is the indispensable resources during human developments. So, how to operate and manage the forest resources scientifically and achieve the sustainable using of forest resource has become the most important thing when human using the forest resources. Research on forests growth and yield model can estimated the stand growth and predicted the stand dynamics accurately,and it has realistic and long-term significance when to achieve the sustainable forest management. What’s more, it can provide plans for the developing measures of forest management scientifically and reasonably. Qinling forest region is one of the biggest forest resources regions, and the stand of Betula albo-sinensis is one of main stand among it. In this study, the stand of natural secondary forest of Betula albo-sinensis is the research objects. By taking use of the plot survey data and national inventory data, a total of 188 data, considering the stand sites index, the stand density index, the stand age and the full stand basal area multiple factors and many more synthetically. Explore the stand growth regularity and establish the growth and yield model of Betula albo-sinensis, based on existing empirical equation. Institute obtained the following conclusions:(1)The relationship between the stand age and other stand factors is: with the stand age increase, the stand average diameter at breast height, the stand average height, the stand basal area and the stand volume increases, but the number of the lived tree decrease, and the stand average growth shows increased at first and then decreased trend. The max stand average growth is 3.58 m3/hm2/yr, when the stand age is 60.(2)This study, Introduced the stand sites index and the stand density index into Schumacher equation, establish the stand basal area growth model of natural secondary forest of Betula albo-sinensis on the southern slope of Qinling mountains. Achieves to estimate the stand basal area at different stand age, stand density and stand sites index. Establish the stand yield model of natural secondary forest of Betula albo-sinensis on the southern slope of Qinling mountains, it can estimate the stand harvest at different stand age and stand sitesindex combined with stand basal area growth equation.The models of Betula albo-sinensis forest established in this study have a higher degree of confidence. Upon examination, the difference between the actual value and the theoretical value calculated by the model is not obvious. It has high accuracy of the models established.These models can provide theoretical basis during the scientific management of the forest of Betula albo-sinensis on the southern slope of Qinling mountains, and has important significance to the forest management measures.