Site Quality Evaluation Of Major Coniferous Forest In Mou Ntainous Area In Central Shandong

The ecological system of forest has a crucial effect on the global ecology and climate.To maintain the vitality of forest ecosystem,it is of vital importance to evaluate the site quality of forests in order to ensure the accurate improvement of forest quality,strengthen scientific afforestation,keep reasonable forest management,and ensure the reasonable decision-making of forest management.Site quality assessment is an important means to study and master forest growth environment and its influence on forest productivity.It is not only the evaluation of forest land quality itself,but also the guidance of forest management and decision-making（such as forest type selection and management mode）.Reasonable and efficient site quality evaluation method is the key to complete scientific afforestation and make more reasonable and efficient forest management.In this study,three tree species,including platycladus orientalis,pinus densifolia a nd pinus logifolia,were selected as the research objects in the related forest farms in the mountainous areas of Shandong province,and various factors affecting the forest s ite quality were studied and analyzed to explore the methods and approaches for site quality evaluation.On the basis of the continuous forest resource inventory data of sh andong planning institute in 2012,the data of field survey and measurement were add ed.Based on the standard plots of each forest farm,233 arboroides orientalis plots,108 chipinus orientalis plots and 181 lobos orientalis plots were selected as the basic d ata.Site-factor method is adopted to improve the multiple linear regression,and status index method is used to select the most optimal forest growth equation fitting analys is and document status experienced two different evaluation methods of the forestry sc ientific and reasonable evaluation on the quality of forest land,and it puts forward th e model of optimizing forest forest management planning advice,to complete the fores t as a whole and individual forest site quality evaluation.（1）Using site-factor method selects the factors that have a significant effect on average high（for grading coefficient treatment）as the independent variable X,The multivariate linear regression model“H=A+A₁X₁+A₂X₂+…A_nX_n”is constructed by taking the average height of small stand H as the dependent variable.The average tree height of the corresponding stand can be calculated by putting the grade coefficient of each factor into the original equation,and the average tree height at the base age（when the age coefficient is 1）can represent the stand quality grade.（2）The Richard equation was selected by the site index method.The non-linear model based on the relationship between the age of dominant wood and the height of the tree obtained by Richard’s model fitting was used to compile the site index table and conduct the corresponding site quality evaluation.According to the fitting results,all the models passed the F test and R² was above 0.85,meeting the accuracy requirements.The model fitting effect is ideal.Based on the results of the above two methods,it is found that the site quality of pinus lateralis,pinus chipini and pinus logiformis plantation in the mountainous area of Shandong province is relatively average,more than half of the sample site quality is only medium,and a considerable part of the forest land with poor site quality still exists.On this basis,the corresponding forest management strategy is put forward to improve the forest farm management plan to promote accurate improvement of forest quality.