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Two-level optimization approach to tree-level forest planning

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Forest Ecosystems 2022年第1期9卷 1-12页

作者： Yusen Sun xingji jin Timo Pukkala Fengri Li Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education School of ForestryNortheast Forestry UniversityHarbin150040HeilongjiangChina University of Eastern Finland P.O.Box 11180101JoensuuFinland

Background:Laser scanning and individual-tree detection are used increasingly in forest inventories.As a consequence,methods that optimize forest management at the level of individual trees will be gradually developed and adopted.Results:The current study proposed a hierarchical two-level optimization method for tree-level planning where the cutting years are optimized at the higher level.The lower-level optimization allocates the trees to the cutting events in an optimal way.The higher-level optimization employed differential evolution whereas the lower-level problem was solved with the simulated annealing metaheuristic.The method was demonstrated with a 30 m30 m sample plot of planted Larix olgensis.The baseline case maximized the net present value as the only management objective.The solution suggested heavy thinning from above and a rotation length of 62 years.The baseline problem was enhanced to mixed stands where species diversity was used as another management objective.The method was also demonstrated in a problem that considered the complexity of stand structure,in addition to net present value.The objective variables that were used to measure complexity were the Shannon index(species diversity),Gini index(tree size diversity),and the index of Clark and Evans,which was used to describe the spatial distribution of trees.The article also presents a method to include natural advance regeneration in the optimization problem and optimize the parameters of simulated annealing simultaneously with the cutting years.Conclusions:The study showed that optimization approaches developed for forest-level planning can be adapted to problems where treatment prescriptions are required for individual trees.

关键词： Differential evolution Heuristic-optimization Individual-tree detection Multi-objective optimization Simulated annealing

Stochastic frontiers or regression quantiles for estimating the self-thinning surface in higher dimensions?

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Journal of Forestry Research 2021年第4期32卷 1515-1533页

作者： Dechao Tian Huiquan Bi xingji jin Fengri Li Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education School of ForestryNortheast Forestry UniversityNo.26 Hexing RoadHarbin 150040People’s Republic of China Forest Science NSW Department of Primary Industries−ForestryLevel 1210 Valentine AveParramattaNSW 2150Australia School of Ecosystem and Forest Sciences The University of MelbourneParkvilleVIC 3010Australia

Stochastic frontier analysis and quantile regression are the two econometric approaches that have been commonly adopted in the determination of the self-thinning boundary line or surface in two and higher dimensions since their introduction to the field some 20 years ago.However,the rational for using one method over the other has,in most cases,not been clearly explained perhaps due to a lack of adequate appreciation of differences between the two approaches for delineating the self-thinning surface.Without an adequate understanding of such differences,the most informative analysis may become a missed opportunity,leading to an inefficient use of data,weak statistical inferences and a failure to gain greater insight into the dynamics of plant populations and forest stands that would otherwise be obtained.Using data from 170 plot measurements in even-aged Larix olgensis(A.Henry) plantations across a wide range of site qualities and with different abundances of woody weeds,i.***.naturally regenerated non-crop species,in northeast China,this study compared the two methods in determining the self-thinning surface across eight sample sizes from 30 to 170 with an even interval of 20 observations and also over a range of quantiles through repeated random sampling and estimation.Across all sample sizes and over the quantile range of 0.90 ≤τ≤0.99,the normal-half normal stochastic frontier estimation proved to be superior to quantile regression in statistical efficiency.Its parameter estimates had lower degrees of variability and correspondingly narrower confidence intervals.This greater efficiency would naturally be conducive to making statistical inferences.The estimated self-thinning surface using all 170 observations enveloped about 96.5% of the data points,a degree of envelopment equivalent to a regression quantile estimation with aτ of 0.965.The stochastic frontier estimation was also more objective because it did not involve the subjective selection of a particular value of τ for the favoured self-thinning surface from

关键词： Larix olgensis Normal-half normal distribution Site productivity Woody weeds Sample size Quantile selection

A management planning system for even-aged and uneven-aged forests in northeast China

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Journal of Forestry Research 2016年第4期27卷 837-852页

作者： xingji jin Timo Pukkala Fengri Li Department of Forest Management School of ForestryNortheast Forestry University Harbin 150040 People's Republic of China University of Eastern Finland P.O. Box 111 Joensuu 80101Finland

The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second,the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest.A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings.Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.

关键词： stand forests timber border alternatives aggregate landscape heuristic instance Northeast

Individual-tree diameter growth model for Korean pine plantations based on optimized interpolation of meteorological variables

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Journal of Forestry Research 2021年第4期32卷 1535-1552页

作者： Man Wang Yinghui Zhao Zhen Zhen xingji jin School of Forestry Northeast Forestry UniversityHarbin 150040HeilongjiangPeople’s Republic of China Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education Northeast Forestry UniversityHarbin 150040HeilongjiangPeople’s Republic of China

To explore the influence of meteorological variables on the growth of Korean pine(Pinus koraiensis Sieb.et Zucc.) plantations and provide a scientific reference for the production and management of Korean pine,three approaches to interpolate meteorological variables during the growing season(i.e.,May-September) were compared in Heilongjiang Province,China.Optimized meteorological variable interpolation results were then combined with stand and individual tree variables,based on data from 56 sample plots and 2886 sample trees from Korean pine plantations in two regions of the province to develop an individualtree diameter growth model(Model I) and an individualtree diameter growth model with meteorological variables(Model Ⅱ) using a stepwise regression method.Moreover,an individual-tree diameter growth model with regional effects(Model Ⅲ) was developed using dummy variables in the regression,and the significance of introducing these dummy variables was verified with an F-test statistical analysis.The models were validated using an independent data set,and the predictive performance of the three models was assessed via the adjusted coefficient of determination(R_(a)^(2)) and root mean square error(RMSE).The results suggest that the growth increment in tree diameter of Korean pine plantations was significantly correlated with the natural logarithm of initial diameter(ln D),stand basal area(BAS),logarithmic deformation of the stand density index(ln SDI),ratio of basal area of trees larger than the subject tree to their initial diameter at breast height(DBH)(BAL/D),and the maximum growingseason precipitation(Pgmax).The individual-tree diameter growth models of Korean pine plantations developed in this study will provide a good basis for estimating and predicting growth increments of Korean pine forests over larger areas.

关键词： Mixed interpolation Korean pine plantations Individual-tree diameter growth model Regional effects

Optimal management of Korean pine plantations in multifunctional forestry

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Journal of Forestry Research 2017年第5期28卷 1027-1038页

作者： xingji jin Timo Pukkala Fengri Li Lihu Dong Department of Forest Management School of ForestryNortheast Forestry University University of Eastern Finland

Korean pine is one of the most important plantation species in northeast China. Besides timber, it produces edible nuts and plantations sequester carbon dioxide from the atmosphere. This study optimized the management of Korean pine plantations for timber production, seed production, carbon sequestration and for the joint production of multiple benefits. As the first step, models were developed for stand dynamics and seed production. These models were used in a simulation-optimization system to find optimal timing and type of thinning treatments and optimal rotation lengths. It was found that three thinnings during the rotation period were optimal. When the amount or profitability of timber production is maximized, suitable rotation lengths are 65-70 years and wood production is 5.5-6.0 m(3) ha(-1) a(-1). The optimal thinning regime is thinning from above. In seed production, optimal rotation lengths are over 100 years. When carbon sequestration in living biomass is maximized, stands should not be clear-cut until trees start to die due to senescence. In the joint production of multiple benefits, the optimal rotation length is 86 years if all benefits (wood, economic profits, seed, carbon sequestration) are equally important. In this management schedule, mean annual wood production is 5.5 m(2) ha(-1) and mean annual seed yield 141 kg ha(-1). It was concluded that it is better to produce timber and seeds in the same stands rather than assign stands to either timber production or seed production.

关键词： Carbon sequestration Edible seeds Multi-objective optimization Pine nuts Pinus koraiensis

单木造材优化嵌入传统林分经营优化中的红松人工林精准经营模式

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东北林业大学学报 2024年第2期52卷 13-20页

作者：徐颖蒋博金星姬 Timo Pukkala 东北林业大学哈尔滨150040 东芬兰大学芬兰•约恩苏

以黑龙江省红松(Pinus koraiensis Siebold et Zuccarini)人工林主要分布区域的标准幼龄林(初植密度2500、3300株/hm~2,地位指数12、14、16 m)为研究对象,利用韦布尔(Weibull)函数预测株数保存率为85%时不同立地指数的红松人工林在10 a... 详细信息

以黑龙江省红松(Pinus koraiensis Siebold et Zuccarini)人工林主要分布区域的标准幼龄林(初植密度2500、3300株/hm~2,地位指数12、14、16 m)为研究对象,利用韦布尔(Weibull)函数预测株数保存率为85%时不同立地指数的红松人工林在10 a时的直径分布;依据红松人工林幼龄标准林分数据,利用人工红松单木-林分基础模型和球果模型构建的林分模拟器对标准林分进行生长模拟,在传统经营优化模式中嵌套单木造材优化,构建单木造材优化嵌入传统林分经营优化中的红松人工林精准经营模式(简称“精准林分经营优化模式”);以木材和球果总净现值最大为目标,对比精准林分经营优化模式、传统林分经营优化模式的差异,分析造材优化对林分经营优化结果、林分经营措施的影响。结果表明:在约束间伐强度和固定下层伐的条件时,与传统经营优化模式相比,精准林分经营优化模式使总经济效益提升6.5%~9.1%。立地条件越好,精准林分经营优化模式对木材净现值增长率、年均木材产量、主伐时林分平均胸径的增量影响越显著,而对年均球果产量、球果净现值增长率的增量影响较小。在同一立地条件时,与传统林分经营优化模式相比,精准林分经营优化模式提升木材净现值增长率对林分初植密度更敏感。

关键词：红松人工林经营模式造材优化净现值

应用优化建模法构建红松人工林单木直径生长模型

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东北林业大学学报 2024年第5期52卷 63-69,74页

作者：吕洁童茜坪金星姬 Timo Pukkala 东北林业大学哈尔滨150040 东芬兰大学

为了提高不完备数据集下红松人工林直径生长模型的预测精度,以1980—2022年黑龙江省75块红松林不同复测间隔期的样地数据(林木胸径、竞争因子和立地等),利用优化建模法构建红松人工林单木直径生长模型,采用单纯形优化算法寻求模拟和实... 详细信息

为了提高不完备数据集下红松人工林直径生长模型的预测精度,以1980—2022年黑龙江省75块红松林不同复测间隔期的样地数据(林木胸径、竞争因子和立地等),利用优化建模法构建红松人工林单木直径生长模型,采用单纯形优化算法寻求模拟和实测直径分布差异最小下的模型参数,并利用自举法对模型进行检验。结果表明:优化建模法损失函数的初始参数a=1、b=0.003、c1=c2=1.5时,预测期末林分断面积偏差为0.02 m^(2)·hm^(-2),显著优于由传统归回建模法的精度(林分断面积偏差为0.44 m^(2)·hm^(-2));结合实测数据与视图分析,验证了优化建模法的优势和可靠性,揭示了优化法损失函数与传统回归法构建的直径生长模型之间的差异。因此,优化法损失函数构建的红松人工林生长模型在模拟自然生长中表现优越,为制定科学的森林经营方案提供了技术支持。

关键词：红松人工林单木生长模型单纯形优化方法自举法

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Erratum to: Optimal management of Korean pine plantations in multifunctional forestry

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Journal of Forestry Research 2017年第5期28卷 1105-1105页

作者： xingji jin Timo Pukkala Fengri Li Lihu Dong Department of Forest Management School of Forestry Northeast Forestry University Harbin 150040 HeilongjiangPeople’s Republic of China University of Eastern Finland P.O. Box 111 80101 JoensuuFinland

In the original publication of Fig. 11 have been the article, Eq. 14 and text in online published incorrectly version is provided in this er The correct ratum (Eq. 14; Fig. 11).

关键词： original provided

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长白落叶松人工林多目标经营模式研究

南京林业大学学报（自然科学版） 2023年第2期47卷 150-158页

作者：宋磊金星姬 PUKKALA Timo 李凤日东北林业大学林学院森林生态系统可持续经营教育部重点实验室黑龙江哈尔滨150040 School of Forest Sciences University of Eastern FinlandJoensuu 11180101

【目的】我国林业目前处于提高森林资源质量和转变发展方式的关键阶段,林分水平的经营决策对科学制订森林经营规程、提高森林质量具有重要意义。利用模拟-优化系统,探究不同林分条件下的最佳经营模式,可为提高黄花落叶松(Larix olgensi... 详细信息

【目的】我国林业目前处于提高森林资源质量和转变发展方式的关键阶段,林分水平的经营决策对科学制订森林经营规程、提高森林质量具有重要意义。利用模拟-优化系统,探究不同林分条件下的最佳经营模式,可为提高黄花落叶松(Larix olgensis)(俗名长白落叶松)人工林多目标经营水平提供理论基础和实施方案。【方法】以标准长白落叶松人工幼龄林为研究对象,利用多属性效用函数和妥协性分析构建包括净现值、大径材产量和林木碳储量的多目标经营模型,链接林分生长模型与粒子群优化算法,优化不同经营方程并提出经营模式。【结果】在不同造林密度(2 500和3 300株/hm^(2))及不同地位指数(16~22 m)下两种多目标方程(MOF1和MOF2)估算的林分主伐年龄为54~96 a,净现值为38 047.8~109 194.9元/hm^(2),大径材年均产量为1.8~4.4 m3/(hm^(2)·a),轮伐期内年均林木碳储量为59.7~103.1 t/(hm^(2)·a)。随着林木碳储量权重的增加(从MOF1到MOF2),大径材产量提高,但净现值降低。【结论】本研究提出的多目标经营模式可以满足对木材产量、质量和经济效益的需求,同时兼顾了森林碳储量,其中多目标经营方程MOF1是权衡各目标效益的折中方案,研究结论对提升我国森林多功能经营管理水平具有重要借鉴意义。

关键词：长白落叶松(黄花落叶松)人工林多目标经营模式净现值大径材产量碳储量