Classification and evaluation of the low-quality and benefit forest of Chinese fir based on GIS.

Taking a case study on the low-quality and benefit forest of Chinese fir at Tongshan forest farm in the hilly area in southern Jiangsu province,these Chinese firs were divided into three grades using the judging function of the incorporate grades to the Chinese fir stand established by analyzing its growth procedure,formation causes and function features,that is,the normal type (first type),the extreme low-quality and benefit type (third type),and the second type between them,with the potential type,the low-quality type and the incorporate low-quality and benefit type as the main characteristics. On the basis of the analysis to the growth procedure and site features under different grade of the stand, the technology parameter criterion used to sort the low-quality and benefit forest of Chinese fir was brought forward. The characteristics of its spatial distribution was clearly visible through the GIS technology by using the Software of Arcview to visualize the classification results of the low-quality and benefit forest of Chinese fir,overcoming the space uncertainty of the traditional method for stand classification.