A Linkage among Tree Diameter, Height, Crown Base Height, and Crown Width 4-Variate Distribution and Their Growth Models: A 4-Variate Diffusion Process Approach
نویسندگان
چکیده
The evolution of the 4-variate probability distribution of the diameter at the breast height, total height, crown base height, and crown width against the age in a forest stand is of great interest to forest management and the evaluation of forest resources. This paper focuses on the Vasicek type 4-variate fixed effect stochastic differential equation (SDE) to quantify the dynamic of tree size components distribution against the age. The new derived 4-variate probability density function and its marginal univariate, bivariate, trivariate, and conditional univariate distributions are applied for the modeling of stand attributes such as the mean diameter, height, crown base height, crown width, volume, and slenderness. All parameters were estimated by the maximum likelihood procedure using a dataset of 1630 Scots pine trees (12 stands). The results were validated using a dataset of 699 Scots pine trees (five stands). A newly developed 4-variate simultaneous system of SDEs incorporated covariance structure driving changes in tree size components and improved predictions in one tree size component given the other tree size components in the system.
منابع مشابه
پیشبینی میزان رشد ابعاد مختلف زیتون تلخ(Melia azedarach) و توت زینتی (Morus alba) در فضای سبز شهری
Determination of growth rate and planting space of trees in urban spaces is needed for the planting design programs and land scape management. To determine the growth rate of two tree species, Chinaberry (Melia azedarach) and Mulberry (Morus alba), data was collected on different dimensions of these trees including, tree height, tree crown height and tree crown diameter at various ages at Pardi...
متن کاملارتباط ماکروفون خاک با گونه های درختی گز و پده در جنگل های حاشیه رودخانه مارون، استان خوزستان
In this study, the abundance and biomass of soil macrofauna were investigated in natural forests of tamarisk and Euphrates poplar in riparian forests of Maroon River in Khuzestan province. Soil macrofauna were collected using 175 sampling plots 50 meter distance from each other on 21 parallel lines with 100 meters distance from each other and perpendicular to the river. Soil macrofauna sampling...
متن کاملTree allometry, leaf size and adult tree size in old-growth forests of western Oregon.
Relationships between tree height and crown dimensions and trunk diameter were determined for shade-tolerant species of old-growth forests of western Oregon. The study included both understory and overstory species, deciduous and evergreen angiosperms and evergreen conifers. A comparison of adult understory species with sapling overstory species of similar height showed greater crown width and ...
متن کاملFunctions for Estimating Stem Diameter and Tree Age Using Tree Height, Crown Width and Existing Stand Database Information
The aim was to investigate the relations between diameter at breast height and maximum crown diameter, tree height and other possible independent variables available in stand databases. Altogether 76 models for estimating stem diameter at breast height and 60 models for tree age were formulated using height and maximum crown diameter as independent variables. These types of models can be utiliz...
متن کاملRelationships of tree height and diameter at breast height revisited: analyses of stem growth using 20-year data of an even-aged Chamaecyparis obtusa stand
Stem diameter at breast height (DBH) and tree height (H) are commonly used measures of tree growth. We examined patterns of height growth and diameter growth along a stem using a 20-year record of an even-aged hinoki cypress (Chamaecyparis obtusa (Siebold & Zucc.) Endl.) stand. In the region of the stem below the crown (except for the butt swell), diameter growth rates (ΔD) at different heights...
متن کامل