2024-03-29T11:00:31Z
http://mcfns.com/index.php/Journal/oai
oai:ojs.mcfns.com:article/156
2021-04-14T18:12:51Z
Journal:Modeling
nmb a2200000Iu 4500
"181030 2018 eng "
1946-7664
dc
COMPARING PROPERTIES OF SELF-REFERENCING MODELS BASED ON NONLINEAR-FIXED-EFFECTS VERSUS NONLINEAR-MIXED-EFFECTS MODELING APPROACHES
Cieszewski, Chris J.
The University of Georgia, USA http://drcjc.com
Strub, Mike
Array
In this study, we compare the properties of self-referencing models, such as various site dependent growth and yield models for predictions of height, diameter, basal area, volume, and density, developed using Nonlinear-Fixed-Effects (NFE) versus Nonlinear-Mixed-Effects (NME) modeling approaches. The properties investigated include the following core traditional well-behaved model characteristics applicable to self-referencing functions: Base-Age-Invariance, Path-Invariance, Indifference Under Model Reparameterization, and Model Conditioning to have the predictions at the base-age equal to the reference point, as well as estimation and prediction statistics such as bias and variance of the fitted versus predicted residuals. The results of this investigation demonstrate that self-referencing models based on the NFE approach possess all the desirable properties associated with logical behavior of the model and estimation statistics, while the NME based self-referencing models lack the well-behaved model properties. We illustrate these properties using an example of fitting self-referencing models to panel data of loblolly pine age-height measurements on a range of sites from the South Africa Correlated Curve Trend Study.
Contemporary Journal Concept Press
2018-10-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/10.11
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 10, No 2: MCFNS October 30, 2018
eng
Universal
Contemporary
Age, Height, Species, plantations
Copyright (c) 2018
oai:ojs.mcfns.com:article/111
2012-09-19T23:09:45Z
Journal:Modeling
nmb a2200000Iu 4500
"120228 2012 eng "
1946-7664
dc
Tree Shape and Branch Structure: Mathematical Models
Yeatts, Dick F
Department of Physics,
Colorado School of Mines, USA http://physics.mines.edu/people/phpfiles/yeatts.php
Array
This study of tree morphology is presented in three parts. Part 1 deals with the over-all shape of trees (their profiles). A mathematical model based on the distribution of leaves shows that all profiles, from rounded to conical, is determined by one parameter. Part 2 deals with the angle of branching. Field measurements show that the sum of the areas of stems exiting a fork is usually greater than the area of the stem entering the fork. Mathematical analysis shows that this “bulking up†actually reduces the quantity of plant tissue incorporated in the branching. Furthermore, the angle of branching increases with the degree of bulking up. Part 3 brings together the concepts of the first two parts: here, the cross-sectional area of the trunk as a function of position along the trunk is determined by the profile of the tree and the angle of side branching off the trunk. From field observation, the profile of a tree (i.e., the outline of its crown) has two prominent characteristics: (i) azimuthal symmetry about the central axis (often the main stem or trunk), as evidenced both in foliage and scaffolding; and (ii) decrease in leaf density from branch-end toward the central axis. From these two conditions (including a presumed radial distribution of leaves) a mathematical model is developed using the calculus of variations that predicts the profile The results of this analysis are consistent with the general observation that profiles range from the nearly spherical in the case of uniform distribution of leaves throughout the crown, to essentially conical when the leaves are found largely on the branch-ends. The results are presented in figures showing theoretical profiles overlaid on photographs of representative trees. Part 2 is based on field measurements that show that the cross-sectional area of a branch (or stem) entering a fork (in the direction of water transport) is less than the sum of the cross-sectional areas of the branches leaving that fork. Again, using the calculus of variations, it is shown that the angle of branching can be related to this “bulking upâ€. Field measurements are in general agreement with this prediction. Part 3 provides a separate test of the validity of the concepts introduced in the first two Parts. Using equations appropriate to a tree with a single main stem and horizontal side branches, the crosssectional area of the trunk is calculated as a function of position on the trunk. The results are compared with field measurements.
Contemporary Journal Concept Press
2012-02-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/MCFNS.4%3A2
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 4, No 1: MCFNS February 28, 2012
eng
Temporar
Contemporary
Copyright (c)
oai:ojs.mcfns.com:article/15
2023-10-20T02:47:08Z
Journal:Modeling
nmb a2200000Iu 4500
"090812 2009 eng "
1946-7664
dc
Modeling Caribbean Tree Stem Diameters from Tree Height and Crown Width Measurements
Brandeis, Thomas
USDA Forest Service, USA
Randolph, KaDonna C.
USDA Forest Service, USA
Strub, Mike
The University of Georgia, USA
Array
Regression models to predict diameter at breast height (DBH) as a function of tree height and maximum crown radius were developed for Caribbean forests based on data collected by the U.S. Forest Service in the Commonwealth of Puerto Rico and Territory of the U.S. Virgin Islands. The model predicting DBH from tree height fit reasonably well (R2 = 0.7110), with strongest in subtropical moist and wet forest. The model predicting DBH from crown radius fit the data poorly (R2 = 0.2876), but improvements were made when the model was fit by forest life zone and crown radius measurement protocol. Models fit with both maximum crown radius and tree height had R-square values that ranged from 0.1803 for the subtropical dry forest to 0.8018 for the subtropical moist forest life zone where crown radius was measured with urban forest inventory protocols. Tree heights had stronger correlations with DBH than did crown radius, perhaps due to difficulties in measuring tree crown width or natural variability in this hurricane-disturbed environment. Models that use tree height have some potential for predicting DBH for use in Caribbean forest biomass and carbon estimation models, but the potential for error propagation by using DBH predicted from crown radius is too great to earn our recommendation for such applications. MCFNS 1(2):78-85. Â
Contemporary Journal Concept Press
2009-08-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
application/postscript
http://mcfns.com/index.php/Journal/article/view/MCFNS.1-78
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 1, No 2: MCFNS August 28, 2009
eng
Puerto Rico; U.S. Virgin Islands
Second Growth;
Crown Width; Height; Diameter
Copyright (c)
oai:ojs.mcfns.com:article/308
2023-10-15T04:45:37Z
Journal:Modeling
nmb a2200000Iu 4500
"230430 2023 eng "
1946-7664
dc
Parameter Estimation And Data-Driven Method For Forest Fire Prediction
Li, X.
Tang, C.
Zhang, H.
Zhang, S.
Li, S.
Wang, Y.
Sun, S.
Liu, J.
Array
Improvement in the accuracy of the forest fire prediction model is essential to properly instructfirefighting forces. The input parameters of traditional prediction method cannot be adjusted in real-time,so the forecasting accuracy will decrease over time. To solve this problem, the forest fire predictionsystembased on parameter estimation and data-driven method is proposed in this paper. First, twodynamic parameters based on the empirical formula, rate of fire spread and main spreading direction,and multi-sensor data are input to a forward prediction model based on the Huygens principle togenerate the predicted fireline for the current time. Secondly, the difference between the predicted andobserved firelines is minimized by the Grey Wolf Optimization algorithm, which derives the optimaldynamic parameters.Finally, the optimal parameters and the current multi-sensor data are input into theprediction model to achieve accurate prediction of the fireline. The burn experiment was designed, andthe feasibilityof the systemwasverifiedbyreal fire data. The results indicate thata fire prediction systemthat quickly calibrates dynamic input parametersis developed and can achieve real-time accurate firepredictions.
Contemporary Journal Concept Press
2023-04-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/15.2
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 15, No 1: MCFNS April 30, 2023
eng
Global
Contemporary
Copyright (c) 2023 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/258
2021-04-10T02:09:22Z
Journal:Modeling
nmb a2200000Iu 4500
"200420 2020 eng "
1946-7664
dc
AN OPTIMIZED MODEL FOR PREDICTING FOREST FIRES AREA BASED ON BINOCULAR VISION
Li, Xingdong
1.College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, Chinaï¼›
2.Northern Forest Fire Management Key Laboratory of the State Forestry and Grassland Bureau, Northeast Forestry University, Harbin 150040, China https://cmee.nefu.edu.cn/
Gao, Hewei
1.College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, Chinaï¼› https://cmee.nefu.edu.cn/
Han, Chengqi
1.College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, Chinaï¼› https://cmee.nefu.edu.cn/
Wang, Yangwei
1.College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, Chinaï¼› https://cmee.nefu.edu.cn/
Hu, Tongxin
1.College of Forestry, Northeast Forestry University, Harbin 150040, China;
2.Northern Forest Fire Management Key Laboratory of the State Forestry and Grassland Bureau, Northeast Forestry University, Harbin 150040, China https://forestry.nefu.edu.cn/
Sun, Long
1.College of Forestry, Northeast Forestry University, Harbin 150040, China;
2.Northern Forest Fire Management Key Laboratory of the State Forestry and Grassland Bureau, Northeast Forestry University, Harbin 150040, China https://forestry.nefu.edu.cn/
Guo, Yanling
Array
 Forecasting of forest fire area is of great significance to effectively control the spread of forest fire. In this paper, the forest fire spreading velocity model and the forest fire spreading simulation technology based on huygens principle are used to estimate the forest fire area. Firstly, binocular camera is used to collect the firing state data of wild forest fire, and segment the firing image, extract the firing line,
locate the firing line and calculate the three-dimensional coordinates of the firing line pixels according to perspective projection model;. Secondly, the forest fire spreading velocity model based on Wang Zhengfei’s model is redesigned. The model parameters of forest fire area were optimized by gradient method. The prediction accuracy is much higher than that of the model before optimization.
Contemporary Journal Concept Press
2020-03-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/12.2
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 12, No 1: MCFNS March 30, 2020
eng
http://mcfns.com/index.php/Journal/article/download/258/0
meadow ï¼›
November
Spreading area
Copyright (c) 2020 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/144
2013-06-18T13:53:14Z
Journal:Modeling
nmb a2200000Iu 4500
"120930 2012 eng "
1946-7664
dc
Self-thinning Limits in Two and Three Dimensions
Garcia, Oscar
University of Northern British Columbia, Canada
Array
The principles behind self-thinning laws and stand density management diagrams are examined. Relationships are analyzed based on trajectories of unthinned and thinned stands in a 3-dimensional state space. Limiting self-thinning lines and planes are demonstrated using a dynamic stand growth model for loblolly pine.
Contemporary Journal Concept Press
2012-09-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/144
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 4, No 2: MCFNS September 30, 2012
eng
Temperate Forests
Second Growth
Copyright (c)
oai:ojs.mcfns.com:article/59
2013-05-18T09:22:31Z
Journal:Modeling
nmb a2200000Iu 4500
"100212 2010 eng "
1946-7664
dc
Using strong inference to falsify differential equation models of sugar maple height growth
Leary, Rolfe A
Rolfe Leary & Associates, USA
Johannsen, Vivian Kvist
University of Copenhagen Hørsholm, Denmark http://en.sl.life.ku.dk/OmSkovOgLandskab/Medarbejdere/vkj.aspx
Array
Platt’s research strategy called 'strong inference' is often studied, but is difficult to apply. Here strong inference is applied in selecting differential equation models of sugar maple, Acer saccharum M., height growth. Two model groups proposed by Zeide (1993; Zeide, B. 1993. Analysis of growth equations. For. Sci. 39(3):594-616) are supplemented with two additional groups, 1) size decline and 2) second order differential equations, nearly exhausting the possible height growth models currently in the literature. A ‘crucial experiment’ was to fit a simultaneous system of equations to height – age data collected from a cohort of trees felled for stem analysis. Models for cohort members are identical in right-hand-sides, have common parameters, but have tree-specific initial heights. Common parameters and tree-specific initial heights are estimated during fitting. Results, based on stem analysis data for a cohorts of from three to five sugar maple growing on 54 plots in the Lake States, showed that all cohort members were predicted by logarithm of time decline (LTD) models to have extremely similar initial heights (less than 0.01 m range), which contradicts experience and leads to their falsification. Three of four models in the time decline (TD) class predict a very small range in final heights, but a large range in initial heights (from 6.4 to 2.9m), hence can also be considered falsified. Size decline and second order models could not be falsified using the height – age cohort data available. MCFNS 2(1):1-11.
Contemporary Journal Concept Press
2010-02-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/MCFNS.2-1
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 2, No 1: MCFNS February 28, 2010
eng
Temperate Forests
Contemporary
Height; Age; Site
Copyright (c)
oai:ojs.mcfns.com:article/309
2023-10-15T04:45:37Z
Journal:Modeling
nmb a2200000Iu 4500
"230430 2023 eng "
1946-7664
dc
Solutions to the Base-Age Variant Models
Cieszewski, Chris J
Mathematical and Computational Forestry & Natural-Resource Sciences http://mcfns.com/index.php
Array
Self-referencing models predict the value of Y at age t as a function of both t and a snapshot
observation of Y = Y 0 at t = t 0 , which implicitly integrates the entire environment affecting the development
of Y . Common examples of such models are site-dependent height over age models, or site index models,
hereafter referred to as site models. These models are often developed using pooled cross-sectional and
longitudinal data and describe families of multiple curve shapes.
It is advantageous to formulate these models as algebraic difference equations, which can be referred to as
“dynamic equations,” with their reference variables describing the environment or site quality. For example,
in height modeling, site models predict height as a function of age and a height at a base-age known as the
site index.
The base-age specific modeling ideology suggests that curves generated by these models are unique to a
particular selection of base-age, at which the input data or site index is defined during the estimation
of model parameters. Base-age variant models are designed to capture some of the patterns of curves
corresponding to different base-ages through a single formula. The curves generated by this approach vary
with base-ages and with various methods in which the models can be applied.
However, the available base-age variant models have been limited in their usage to avoid inconsistent
predictions and cannot be considered equations in the algebraic sense since they can show that 1 = 0. To
address this issue, I present a mathematical approach that leads to the derivation of a new type of proper
base-age invariant equations, which can be applied in various alternative ways for the same purpose as the
base-age variant models, but without creating mathematical inconsistencies.
Contemporary Journal Concept Press
2023-04-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/15.3
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 15, No 1: MCFNS April 30, 2023
eng
Global
Contemporary
Age; diameter; height; volume.
Copyright (c) 2023 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/264
2023-10-20T02:45:49Z
Journal:Modeling
nmb a2200000Iu 4500
"200420 2020 eng "
1946-7664
dc
CROWN ASYMMETRY AND NICHE SEGREGATION AS AN ADAPTATION OF TREES TO COMPETITION FOR LIGHT: CONCLUSIONS FROM SIMULATION EXPERIMENTS IN MIXED BOREAL STANDS
Shanin, Vladimir
Institute of Physicochemical and Biological Problems in Soil Science of the Russian Academy of Sciences http://orcid.org/0000-0002-8294-7796
Grabarnik, Pavel
Shashkov, Maxim
Ivanova, Natalya
Bykhovets, Sergey
Frolov, Pavel
Stamenov, Miroslav
Array
Most models of forest communities cannot represent the asymmetry of crowns resulting from inter-tree competition. However, this is important for the accurate simulation of mixed and uneven-aged forest stands. In the paper we propose a new model, which is individual-based and spatially-explicit, i.e., taking into account the relative positions and properties of all competing trees in a forest stand. The model uses species-specific coefficients, thus it allows to take into account the different strategies of competition for light. The model operates with the 3D-representation of tree crowns and light transmission through the canopy, with discrete spatial and temporal resolution. It thus enables to represent the asymmetry of the crown shape and biomass distribution in response to the local surrounding of a given tree. In order to estimate the performance of the model in the simulation of aboveground competition, a set of simulation scenarios, representing stands of different spatial structures, ages, and species compositions, was used. Simulations showed the positive effect of species mixture on crown size and light interception efficiency, as well as species- and age-related dependencies of these parameters. Differences in the spatial structure mostly affected the light transmission pattern at the stand level. The importance of crown asymmetry in the increase in light interception efficiency was also shown. Thus, the proposed model allows simulating light absorption by the canopy with a high spatial resolution, using relatively few parameters. The model imitates a mechanism allowing trees to decrease the aboveground competition in forest stands and it also is applicable for simulating aboveground competition in mixed uneven-aged stands.
Contemporary Journal Concept Press
2020-03-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/12.3
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 12, No 1: MCFNS March 30, 2020
eng
Boreal Forests, Europe
Year
Species, Individual Trees
Copyright (c) 2020 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/142
2013-03-21T22:51:10Z
Journal:Modeling
nmb a2200000Iu 4500
"120930 2012 eng "
1946-7664
dc
Generalization of the Coefficient of Determination or R-square and its application to Self-Referencing Models
Strub, Mike
The University of Georgia, USA
Cieszewski, Chris J
The University of Georgia, USA http://drcjc.com
Array
The traditional coefficient of determination or R-square is the proportion of variation explained by a regression model versus the variation explained by the mean. This measure does not discriminate well between alternative self-referencing models such as site index curves. A generalized R-square based on the proportion of the variation explained by the self-referencing model versus the variation explained by a straight line through zero for each growth series provides better discrimination between candidate models. Three growth series from the South Africa Correlated Curve Trend Study are used to illustrate the difference between the traditional R-square and the generalized R-square.
Contemporary Journal Concept Press
2012-09-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/142
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 4, No 2: MCFNS September 30, 2012
eng
Wordwide
Contemporary
Site-Height-Age data from South Africa
Copyright (c)
oai:ojs.mcfns.com:article/67
2013-05-18T09:23:20Z
Journal:Modeling
nmb a2200000Iu 4500
"100218 2010 eng "
1946-7664
dc
Using strong inference to falsify differential equation models of sugar maple height growth---Discussion
Zeide, Boris
Professor Emeritus, University of Arkansas, USA http://www.afrc.uamont.edu/zeideb/index.htm
Array
Leary and Johannsen (2010; Leary and Johannsen. 2010. Using strong inference to falsify differential equation models of sugar maple height growth. MCFNS 2:1-11) envision growth modeling as a search for a single precise line like those depicting the laws of physics. However, it is unlikely that such a complex process as tree growth can be captured by our simple, usually empirical models. Instead of carrying out the experiment so as to get a clean result, it may be more realistic to start with enclosing the field of growth trajectories between two boundary lines representing the two opposite explanations of a studied relationship. Understanding complex process is more likely by combining opposites rather than falsifying one of them. Then, the modules delineating the boundaries can be joint in a single model that describes a more complex and fluid central tendency. MCFNS 2(1):12-14.
Contemporary Journal Concept Press
2010-02-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/MCFNS.2-12
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 2, No 1: MCFNS February 28, 2010
eng
Global
Contemporary
Analytical
Copyright (c)
oai:ojs.mcfns.com:article/284
2023-10-19T13:09:01Z
Journal:Modeling
nmb a2200000Iu 4500
"201030 2020 eng "
1946-7664
dc
Optimizing the Rothermel model for easily Predicting spread rate of forest fire
Hua, Jun
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Zhang, Shiyu
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Gao, Hewei
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Chen, Xiandong
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Li, Xingdong
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Northern Forest Fire Management Key Laboratory of the State Forestry and Grassland Bureau
Liu, Jiuqing
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China
Array
Rothermel model is a common method for predicting forest fire spread rate, but Its application is limited, due to complexity of the formula and too many parameters. In this paper, the Rothermel model is optimized to a simple format, which contains 4 independent variables as input, 1 dependent variable as output and 8 parameters to be estimated. In order to validate the effectiveness of the optimized model, the indoor ignition experiment is designed and carried out, and then the fire spreading data is collected and processed in advance for training the parameters of the model. By analyzing the effectiveness of 3 nonlinear optimizing methods , the Levenberg-Marquardt(LM) method is chosen to estimated the parameters of the model. At last, by comparing to the actual measured value, precision of the optimized model is validated on the verification data, and with the ability to predict the speed of fire spreading in the indoor laboratory.
Contemporary Journal Concept Press
2020-10-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/12.5
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 12, No 2: MCFNS October 30, 2020
eng
Copyright (c) 2020 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/172
2023-10-20T02:45:42Z
Journal:Modeling
nmb a2200000Iu 4500
"140330 2014 eng "
1946-7664
dc
The Role of Age-Structure in the Optimal Germination Fraction of Seeds
Webster, Amy K.
Institutional Affiliations: Department of Genetics, University of Georgia,
Athens, GA 30602. http://www.promislowlab.org/currentpeople.html
Cieszewski, Rene
University of Georgia
Promislow, Daniel
University of Georgia http://www.genetics.uga.edu/people_bio_promislow.html
Array
When a plant living in an unpredictable environment produces seeds, its ideal strategy might not be to have all seeds germinate at once. What is the germination fraction that will maximize a plant's fitness, allowing the plant to hedge its bets in case of a poor year? To answer this question, in his now classic 1966 paper, Dan Cohen worked out the optimal annual germination fraction for seeds in a fluctuating environment. His result was elegant, but relied on a series of simplifying assumptions. We focus here on two specific assumptions. Namely, Cohen assumed that the population consists of annual plants, which have no adult age-structure, and that a seed's age has no effect on whether or not it will germinate. We review empirical and theoretical papers that have considered what happens when one or both of these assumptions is relaxed. More than a half-century has passed since Cohen's landmark study, and yet the existing literature has yet to provide theoretical solutions for perennial species as Cohen was able to do for annuals. Empirical studies have addressed short-lived perennials with minimal seed dormancy. However, perennials with longer lifespans and significant dormancy, such as many species of trees, are left largely unexplored. In this light, we conclude our review with ideas that we hope will encourage future research on both theoretical and experimental aspects of this important problem.
Contemporary Journal Concept Press
2014-03-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/6_26
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 6, No 1: MCFNS March 30, 2014
eng
Global
Seeding and Germination; Regeneration;
Age-Structure; Annual vs. Perennial
Copyright (c)
oai:ojs.mcfns.com:article/69
2013-05-18T09:23:52Z
Journal:Modeling
nmb a2200000Iu 4500
1946-7664
dc
Using strong inference to falsify differential equation models of sugar maple height growth---Rejoinder
Leary, Rolfe A
Rolfe Leary & Associates, USA http://drcjc.com
Johannsen, Vivian Kvist
University of Copenhagen Hørsholm, Denmark http://en.sl.life.ku.dk/OmSkovOgLandskab/Medarbejdere/vkj.aspx
Array
We provide here our response to Zeide (2010) comment (Zeide, B. 2010. Using strong inference to falsify differential equation models of sugar maple height growth---Discussion. MCFNS 2:12-14) on our earlier article of the same title. MCFNS 2(1):15-17.
Contemporary Journal Concept Press
2010-02-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/MCFNS.2-15
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 2, No 1: MCFNS February 28, 2010
eng
Temperate Forests
Contemporary
Height; Age; Site
Copyright (c)
oai:ojs.mcfns.com:article/292
2021-04-14T23:00:02Z
Journal:Modeling
nmb a2200000Iu 4500
"210330 2021 eng "
1946-7664
dc
UTADA: Unified Theory of the Algebraic Differences Approaches---Derivation of Dynamic Site Equations from Yield-Site Relationships
Cieszewski, Chris J.
The University of Georgia http://mcfns.com/index.php
Array
Dynamic-equation-based self-referencing models of the form: Y=f(y0,t0,t) describe changes in Y as a function of two variables: one longitudinal variable t, and one unobservable cross-sectional variable X. Traditionally, X is represented implicitly by its substitution of a snapshot value of Y, (y0), at an arbitrary value of t, (t0). The unobservable variable X represents the environment potential, which cannot be directly measured or precisely defined due to its extreme complexity and variability. While the most elusive and difficult in handling, X is the most critical variable of the dynamic site equations due to its disproportionate impact on the modeled dynamics, yet, all traditional approaches to such modeling are predominantly based on a detailed analysis of primarily longitudinal relationships Y=u(t), which subsequently, to be helpful in practice, are modified into the self-referencing forms. All the former approaches devote little to no effort to explicitly model the cross-sectional relationships governed by the unobservable variable X.
The presented approach unifies the modeling efforts of defining yield and site relationships equally by focusing primarily on direct mathematical formulations describing the theory of their interaction. This approach considers the variable t only in the secondary analysis, adding it to the model through modifying the final model parameters. Despite the somewhat elusive nature of exploring the unobservable properties of the site, the new approach appears to be highly empowering by analyzing more direct yet more robust relationships between Y and X as opposed to those between Y and t.
Contemporary Journal Concept Press
2021-03-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/13.4
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 13, No 1: MCFNS March 30, 2021
eng
Global
Contemporary
Yield; height; site index; age; volume;
Copyright (c) 2021 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/242
2021-04-14T18:13:51Z
Journal:Modeling
nmb a2200000Iu 4500
"180330 2018 eng "
1946-7664
dc
Forks in my road toward more mathematics in forest dynamics models (An Invited Autobiographical Note)
Leary, Rolfe A
Rolfe Leary & Associates
Array
This note describes personal fits and starts in the author’s career seeking an education to permit a serious use of applied mathematics in forest dynamics research. The personal journey through mathematics, while maintaining roots in forest dynamics, was not very efficient, and the sought after goal of universal description remains only partially tested. It would appear that significant improvement has been made in representing sugar maple height growth, based on application of 14 different differential equation models found in the literature over the last 175 years, but causal environmental variables are not identified.
Contemporary Journal Concept Press
2018-03-30 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/10.3
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 10, No 1: MCFNS March 30, 2018
eng
North America
1822-1994
Literature on growth equations.
Copyright (c) 2018 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)
oai:ojs.mcfns.com:article/66
2011-05-01T22:36:58Z
Journal:Modeling
nmb a2200000Iu 4500
"100814 2010 eng "
1946-7664
dc
Growth and Survival of Eucalyptus grandis - a study based on modelling lifetime distributions
Dickel, Meike
Christian-Albrechts-University Kiel, Germany
Kotze, Heyns
Komatiland Forests (Pty) Ltd., Nelspruit, South Africa
von Gadow, Klaus
University of Göttingen, Germany
Zucchini, Walter
University of Göttingen, Germany
Array
This study presents a new approach to estimating density-dependent survival and growth in four experimental plots of Eucalyptus grandis.
planted at different densities on a homogeneous site in Zululand/South Africa. Estimates of future basal area could be improved considerably by first estimating the number of surviving trees and including this estimate in the basal area predictions.
We estimate the probability of survival of a single tree using a Weibull distribution. Because we only know the number of trees that died between two observations points and not the exact time points of their death, the maximum likelihood estimation was adjusted to deal with these interval-censored data.
The estimated shape and scale parameters show an exponential relationship with the initial number of planted trees.
The relationship proved to be useful for estimating the shape and scale parameters of the lifetime distribution for any given initial number of planted trees.
The number of surviving trees $(N2)$ at time $t2$, given that there were N1 trees at the initial time point, is binomially distributed.
The binomial probability represents the weight for the calculation of the unconditional distribution of stand basal areas.
This procedure is useful for obtaining a better understanding of the distribution of future stand basal areas.
It was found that the basal area expectation values differ over time, but the variance of the basal areas remains almost constant for all ages and planting densities.
Our approach of estimating future basal area, based on modeling lifetime distributions, proved to be superior to convential methods. MCFNS 2(2):86-96.
Contemporary Journal Concept Press
2010-08-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/MCFNS.2-86
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 2, No 2: MCFNS August 28, 2010
eng
South Africa
last 50 years
different densities
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oai:ojs.mcfns.com:article/4
2011-05-01T23:02:16Z
Journal:Modeling
nmb a2200000Iu 4500
"090202 2009 eng "
1946-7664
dc
A simple and effective forest stand mortality model
Garcia, Oscar
University of Northern British Columbia, Canada
Array
A whole-stand survival model is presented, that is parsimonious and well-behaved when extrapolated, making it particularly useful in data-poor situations. It is argued, on biological and system-theoretical grounds, that a suitable differential equation for the mortality rate should contain number of trees and top height on the right-hand side, avoiding age, mean diameter, or basal area. Following Eichhorn's hypothesis, site quality can be neglected by modelling rates relative to height growth. The proposed model is $\dr{N}{H} = -a N^b H^c$ , where $N$ is number of trees per unit area, $H$ is top height, and $a$, $b$ and $c$ are parameters to be estimated. The equation can be integrated to predict mortality between any two points in time. Satisfactory performance is demonstrated with a white spruce data set from British Columbia. It is shown that the model generalizes concepts of relative spacing, and mortality models for radiata pine and Douglas-fir used by Beekhuis in New Zealand in the 1960's. Asymptotic behaviour is related to the 3/2, Reineke, and relative spacing self-thinning laws. Limitations of the self-thinning theories and relationships among their various forms are discussed. MCFNS 1(1):1-9.
Contemporary Journal Concept Press
2009-02-28 00:00:00
Peer-reviewed Modeling Papers
application/pdf
application/postscript
http://mcfns.com/index.php/Journal/article/view/MCFNS.1-1
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 1, No 1: MCFNS February 28, 2009
eng
Worldwide, forests populations
contenporary
density, diameter, height, volume,
Copyright (c)
oai:ojs.mcfns.com:article/293
2023-10-19T13:35:46Z
Journal:Modeling
nmb a2200000Iu 4500
"211101 2021 eng "
1946-7664
dc
EXPERIMENT AND RESEARCH ON PREDICTION MODEL OF FOREST FIRE SPREAD BASED ON ENSEMBLE KALMAN FILTER
Zhang, Shiyu
Northeast Forestry University http://orcid.org/0000-0003-4258-0333
Liu, Jiuqing
Northeast Forestry University
Gao, Hewei
Northeast Forestry University
Chen, Xiandong
Northeast Forestry University
Li, Xingdong
Northeast Forestry University
Hua, Jun
Northeast Forestry University
Hu, Haiqing
Northeast Forestry University
Array
The spread of forest fire is an extremely complex and harmful natural phenomenon. At present, the forest fire spread model has some shortcomings, such as complex formula, inaccurate simulation value and so on. In this paper, the Ensemble Kalman Filter(ENKF) algorithm is applied to the field of forest fire spread so that it can better predict the spread of forest fire. Firstly, the Rothermel forest fire speed formula is simplified, and the simplified Rothermel speed value is modified by the actual measured forest fire spread speed value, so that the optimal model simulation value is obtained. Then the optimal speed is input into Cellular Automata(CA) to simulate the spread of forest fire. Secondly, the experiment is carried out by changing the slope, bed thickness, moisture content, load and wind speed. And the actual measured speed value, the simplified Rothermel model value and the optimized value after ENKF are compared in the process of fire spread. Finally, The experimental results show that the error of fire spread speed corrected by ENKF is smaller, the forest fire spread contour obtained from the optimal speed value by ENKF is closer to the actual fire spread contour, and the highest similarity index is 0.854. The model proposed in this paper has the ability to predict the spread of forest fire indoors.
Contemporary Journal Concept Press
2021-11-01 06:02:50
Peer-reviewed Modeling Papers
application/pdf
http://mcfns.com/index.php/Journal/article/view/13.6
Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol 13, No 2: MCFNS October 30, 2021
eng
Forest
Origin
Copyright (c) 2021 Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS)