Site quality evaluation and growth harvest benefit of Pinus koraiensis plantation
[Objective]Taking the 60-year-old Pinus koraiensis plantation in the eastern section of the humid climate zone of the temperate zone as the research object,the most suitable site type combination was selected.The growth characteristics of dominant factors,standing volume and stand volume were analyzed to provide scientific basis for the intensive and sustainable management of P.koraiensis plantation.[Method]Using the Quantification Theory I model to analyze the relationship between stand growth and site factors,and to evaluate site quality and classify site types.Use systematic clustering method to classify the level of site types.Linear fit the predicted values of the site evaluation results with the measured values of the site survey to determine the reliability of the evaluation results.Using redundancy analysis to explore the dominant factors affecting stand growth in forest density and soil chemical indicators,and analyzing the quantitative relationship between the dominant factors and forest volume by drawing scatter plots.[Result]1)Based on the quantitative theory I model,30 site types were divided,among which the site combination of 600-700 m altitude,shady slope,slope,thick organic matter layer and medium humus layer was the best.The coefficient of determination R2 of the linear fitting between the predicted value and the measured value of each site type was 0.758,and the P value was significant at the 0.001 level;2)When the site types were classified into five grades by the hierarchical clustering method,the site types of grade Ⅰ-Ⅴ accounted for 13.3%,43.3%,20%,20%and 3.33%;3)Richards function had the best fitting effect on the dominant trees of 60 year old P.koraiensis plantation.RSS,RMSE and R2 were 21.566,0.202 and 0.886,respectively.The p value was significant at the level of 0.001.The relationship between height and DBH of dominant trees was H=24.569(1-e-0.162D)5.199;4)The plant number density had the most significant effect on the growth of 60-year-old P.koraiensis plantation in this study area(accounting for 54.3%,F=89.2,P=0.002).The maximum stand volume of a 60-year-old P.koraiensis plantation was approximately 550 m3/hm2.[Conclusion]In general,the site quality of P.koraiensis plantations with low altitude,shady slope,gentle slope,thick organic matter layer and humus layer is high.The plant number density has the greatest impact on the growth characteristics of P.koraiensis plantation,and follows the"certain rule of final harvest".It is suggested to apply fertilizer appropriately or regulate stand density for scientific management.
Pinus Koraiensissite classificationsite quality evaluationquantity theory Ⅰredundancy analysisstand volume
NETL
NSTL
万方数据
