Investigating Diameter-Height Models of Fagus and Carpinus betulus Forest in Area 40 A of Noshahr (Mazandaran)

Subject Areas : forest

Nastaran  Nazariani ¹ (MSc. Student of forest management, Department of Natural Resources, University of Agricultural Sciencesand Natural Resources of Sari)
Seyedeh Kosar  Hamidi ² (student of Forestry, Faculty of Natural Resources, University of Agricultural Sciences and Natural Resources, Sari, Sari, Iran)
Ramin  Mansour Samaei ³ (PhD student in Forestry, Faculty of Natural Resources, Sari University of Agricultural Sciences and Natural Resources)

Received: 2019-07-15 Accepted : 2021-02-13 Published : 2021-05-22

Keywords: Modeling, Carpinus betulus, Nonlinear regression, Diameter-height, Korf model,

Abstract :

Modeling the frequency distribution of variables such as diameter and height of trees as an important factor in the growth and performance of various branches of forest science such as forestry, forestry and biometrics in order to provide sustainable management and proper planning of forest resources. Altitude and diameter equations are often used to estimate the height of trees when only the diameter of the trees is measured. In the present study, 12 nonlinear elevation and diameter models were fitted for data of Beech and Hornbeam forests in the Nawshahr (Mazandaran) Area 40 A. The data were divided into two categories. 70% of the data was used for modeling and 30% for validation. In order to select the optimal model, moderate explanation coefficient criteria, mean square error and error were used. The results of different models showed that the Korf model with the coefficients of error, irregularity and mean squared error (R2 = 0.68), (BIAS = 0.52) and (RMSE = 5.82) for modeling and respectively (R2 = 0.68) (BIAS = 0.30) and (RMSE = 5.41) for validation, is a suitable model for the diameter-altitude relationship in the studied area. With regard to aspects of mathematical and biological models studied in this research, korf model as the final model to predict the height of Fagus and Carpinus betulus forests in the area is recommended.