Classification and Quality Evaluation of Forest Site Types by Using Compartments as the Research Scale

LU Lihua;FENG Yiming;NONG You;LI Hua;NONG Liangshu;SUN Dongjing;HUANG Dewei;MING Angang;Experimental Center of Tropical Forestry,Chinese Academy of Forestry;Guangxi Youyiguan Forest Ecosystem Research Station;Institute of Desertification Studies,Chinese Academy of Forestry;

compartment scale;;site type classification;;site quality evaluation;;site index;;fertility index

Sampling plots with a density of 7 hm~2/plot were distributed and set up based on the results of National Forest Resource Inventory in the Shaoping Experimental Station of Experimental Center of Tropical Forestry,Chinese Academy of Forestry in Guangxi,China. After previous site selection on the forest map,site investigations and plot setting were conducted for acquisition of site properties. the site types classification guiding factors were found out through the Principal Components Analysis method. According to the "Six-level classification system"from "Forest site classification in China",the data from field study were overlaid in the Arc GIS software to obtain forest site types and related figures,and the site quality was evaluated through comprehensive evaluation method. Results showed that there were 88 site types which were included in 2 blocks and 3 groups in the study area,being pertained to 5 levels of site quality as follows Level I: none; Level II: 4 site types with total area of 48. 87 hm~2,accounting for 1.44%; Level III: 11 site types with total area of 106. 42 hm~2,accounting for 3. 14%; level IV: 52 site types with total area of 2799. 21 hm~2,accounting for 82. 65%; and level V: 19 site types with total area of 432.36 hm~2,accounting for12. 77%. There were 15 site types with the site quality level of middle or above,accounting for a total area of 155. 29 hm~2 or 4. 58% in the whole study area,while the site type with the site quality level being low or lower was 73 with the area of 3 231. 57 hm~2 accounting for 95. 42%.