Features and Partial Derivatives of Bertalanffy-Richards Growth Model in Forestry
نویسندگان
چکیده
The Bertalanffy-Richards growth model is employed more than any other models for forest growth and yield modelling. However, its features have not completely been recognised. As a result, misunderstanding of the model still appears in some papers published in forest journals. A study by [1] is cited here as an evidence of the misunderstanding. This paper tries to explain different features of the Bertalanffy-Richards growth model based on the different conditions of the allometric parameter and introduces an assessment software to easily get the partial derivatives with respect to each parameter when more complex techniques (e.g., the Marquardt method) are employed to estimate parameters of any nonlinear models. This paper indicates that [1] study appears some unreasonable evidences of nonlinear growth models from a forestry perspective.
منابع مشابه
Evaluation of Non- linear Growth Curves Models for Native Slow-growing Khazak Chickens
Native poultry is a valuable genetic source with high resistance against diseases providing an important subject for breeding programs. The non-linear mathematical modeling of the growth pattern may partly explain the relationship between requirements and body weight to precise feeding that plays a vital role in the animal enterprises. A study was conducted to compare five non-linear models inc...
متن کاملGrowth of fishes, crustaceans and molluscs: estimation of the von Bertalanffy, Logistic, Gompertz and Richards curves and a new growth model
A total of 16 data sets on wild and cultivated fishes, crustaceans and molluscs were used to test and compare conventional growth curves (von Bertalanffy, Logistic, Gompertz and Richards) and a new growth model. Statistical properties for estimation of the models were evaluated and compared to determine suitability. The absolute value of the Hougaard measure of skewness of parameter estimates (...
متن کاملEffect of Temperature and pH on Formulating the Kinetic Growth Parameters and Lactic Acid Production of Lactobacillus bulgaricus
Background and Objectives: Lactobacillus delbrueckii ssp bulgaricus is widely used in dairy industries as a starter for yogurt production. This study was designed using response surface methodology (RSM) in 12 batch pH-controlled cultures of Lactobacillus delbrueckii sub-ssp. bulgaricus for determining the effect of temperature and pH on the biomass production of a native strain of L. bulgaricu...
متن کاملEvaluation of Models to Describe Temporal Growth in Local Chickens of Ghana
The logistic, Gompertz, Richards and asymmetric logistic growth curve models were fitted to body weight data of local Ghanaian chickens and French SASSO T44 chickens. All four growth models provided good fit for each sex by genotype growth data with R2 values ranging from 86.7% to 96.7%. The rate constant parameter, k, ranged between 0.137 and 0.271 and were significantly different from zero fo...
متن کاملNew Dimensions in Gompertzian Growth
The Gompertz function was formulated to represent an actuarial curve, yet it often fits growth of organisms, organs and tumors. Despite numerous attempts, no consensus has been forged about the biological foundation of the broad applicability of the model. Here we revisit the Gompertzian notion of the "power to grow" and equate it with growth fraction. Aside from conferring biological interpret...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2004