TAILIEUCHUNG - Effects of adding crown variables in stem taper and volume predictions for black pine

Crown characteristics are an important component of growth and yield models. The stem form of a tree depends to a large extent on the tree crown dimensions. However, there is no unified agreement on whether crown variables (crown ratio and crown length) should be incorporated into taper models for accurate predictions of diameter and volume. | Turkish Journal of Agriculture and Forestry Research Article Turk J Agric For (2013) 37: 231-242 © TÜBİTAK doi: Effects of adding crown variables in stem taper and volume predictions for black pine 1, 2 Ramazan ÖZÇELİK *, Cafer BAL Faculty of Forestry, Süleyman Demirel University, East Campus, 32260 Isparta, Turkey 2 Forest Engineering, Konya Forest Nursery Enterprise, Konya, Turkey 1 Received: Accepted: Published Online: Printed: Abstract: Crown characteristics are an important component of growth and yield models. The stem form of a tree depends to a large extent on the tree crown dimensions. However, there is no unified agreement on whether crown variables (crown ratio and crown length) should be incorporated into taper models for accurate predictions of diameter and volume. The purpose of this study was to investigate the level of improvement that the incorporation of crown variables into taper equations for black pine (Pinus nigra subsp. pallasiana (Lamb.) Holmboe) gives to diameter and stem volume predictions Linear and nonlinear crown variable functions were incorporated into a compatible volume and taper equation to evaluate their effect in model prediction accuracy. The inclusion of crown variables provided significantly different parameter estimates but only resulted in a modest reduction of fitting statistics for both diameter and volume with lower average bias and lower mean squared errors for all modified models, although the improvement in stem volume prediction was minimal. Based on the results, the improvement obtained by the inclusion of crown variables is not enough to justify the additional costs in measuring crown variables of standing trees for volume estimation. Key words: Crown ratio, crown length, diameter, segmented taper model 1. Introduction Stem taper and stem volume are the 2 most valuable tree .

• Nông nghiệp
• Black pine
• Crown ratio
• Crown length
• Segmented taper model
• Crown variables
• Fire behavior
• Slash fuel
• Pinus nigra
• Anatolian black pine
• Calabrian pine Pinus brutia L
• BMC Plant Biology
• Pinus thunbergii
• Pine wood nematode
• Pine wood disease
• Genetic linkage map
• Surface roughness
• Wood sanding
• Wood planing
• European black pine
• Lombardy poplar
• Dry weight fraction
• Osmotic potential
• Root growth potential
• Phenological conditions
• Environmental factors
• Tree growth
• Wood treatability
• Climate–tree–growth relationship
• Fire growth
• Line fire
• Point fire
• Litter fuel
• Fertility tables
• Intrinsic rate of increase
• Pine wilt disease
• Bursaphelenchus xylophilus
• Corn stalk
• Turkish black pine
• Medium density fiberboard
• Chemical composition
• Fiber properties
• Physical and mechanical properties
• Báo cáo lâm nghiệp hay
• cách trình bày báo cáo
• báo cáo lâm nghiệp
• công trình nghiên cứu lâm nghiệp
• tài liệu về lâm nghiệp
• Black pine Pinus nigra Arnold
• Height–diameter model
• Gompertz model
• Forest management
• Taurus cedar
• Ecoregion based height diameter models
• Estimate individual tree biomass
• Importance sampling
• Randomized branch sampling
• Above ground tree biomass