Stem taper functions for white birch (Betula platyphylla) and costata birch (Betula costata) in the Xiaoxing’an Mountains, northeast China
Autor: | Muhammad Khurram Shahzad, Amna Hussain, Lichun Jiang, Harold E. Burkhart |
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Rok vydání: | 2021 |
Předmět: |
0106 biological sciences
Stem taper Betula costata White (horse) biology Forestry 04 agricultural and veterinary sciences biology.organism_classification 01 natural sciences 040103 agronomy & agriculture 0401 agriculture forestry and fisheries China 010606 plant biology & botany Mathematics Betula platyphylla |
Zdroj: | Forestry: An International Journal of Forest Research. 94:714-733 |
ISSN: | 1464-3626 0015-752X |
Popis: | White birch (Betula platyphylla Sukaczev) and costata birch (Betula costata Trautv.) are valuable hardwood tree species growing in northeast China. Several taper studies have analysed birch species in the countries harbouring the boreal forests. However, this study presents an initial attempt to develop stem taper models using the fixed-and mixed-effects modelling for white birch and costata birch in Xiaoxing'an Mountains, northeast China. Ten commonly used taper models were evaluated by using 228 destructively sampled trees of both tree species comprising of 4582 diameter and height measurements. The performance of these models was tested in predicting diameter at any height, total volume and merchantable volume (10 and 20 cm top diameters). We incorporated a second-order continuous-time error structure to adjust the inherent autocorrelation in the data. The segmented model of Clark best predicted the diameter and total or merchantable volume when the upper stem diameter at 5.3 m was available. When diameter measurements at 5.3 m were not available, the models of Kozak and Max and Burkhart were superior to other models for white birch and costata birch, respectively. After model comparison, the best model of Clark was refitted as the NLME model. National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [31570624]; Heilongjiang Touyan Innovation Team Program Published version National Natural Science Foundation of China (31570624); Heilongjiang Touyan Innovation Team Program. |
Databáze: | OpenAIRE |
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