scholarly journals Improving the efficiency of forest management based on the optimization of non-continuous felling of growing plantations

Author(s):  
С.М. Базаров ◽  
Ю.И. Беленький ◽  
И.В. Бачериков ◽  
Д.А. Ильюшенко ◽  
М.В. Базарова ◽  
...  

В результате анализа динамических таблиц роста высокопродуктивных сосновых, эвкалиптовых и акациевых насаждений с достаточно коротким оборотом рубок установлено, что в процессе роста древостоев общий объем уменьшения биомассы в результате естественного отпада деревьев равен (сосна) или превосходит (эвкалипт, акация) асимптотическое значение, соответствующее спелому состоянию. Поэтому равномерно-постепенные рубки древостоев по классам возрастов в сочетании со сплошными рубками спелых древостоев обеспечивают получение максимально возможного объема биомассы выращиваемых насаждений. Анализ динамического состояния системы «лес– заготовка» с позиции решения кинетических уравнений экологической модели «зайцы–лисы» (зайцы – лес, лисы – заготовка) указывает на возможность устойчивого осциллирующего состояния лесопользования при естественном возобновлении ресурсов. В результате решения кинетических уравнений становятся возможными определение частоты устойчивых осцилляций системы «лес–заготовка» (решение прямой задачи) и реализация принципа гармонии природных и техногенных систем. Здесь процесс заготовки осуществляется несплошными (равномерно-постепенными) рубками, роль класса возрастов выполняет период колебания, соответствующий определяемой частоте. Данный подход предполагает также решение обратной задачи: при выбранных частоте устойчивых осцилляций системы и динамике роста насаждений – определение соответствующих параметров заготовки. Analysis of the dynamic state of the system «forest–harvesting» from the standpoint of solving the kinetic equations of the ecological model «hares–foxes» (hares – forest, foxes – harvesting) indicates the possibility of a sustainable oscillating state of forest management with the natural renewal of resources. As a result of the kinetic equations solution it becomes possible to determine the frequency of stable oscillations of the forest- harvesting system (direct problem solution) and to realize the principle of natural and man- made systems harmony. Here the process of harvesting is carried out by non-flat (evenly- gradual) felling, the role of the age class performs the period of oscillation corresponding to the determined frequency. With this approach, it is possible to formulate the same inverse problem: the chosen frequency of stable oscillations of the system and the growth dynamics of plantings to determine the appropriate parameters of the work piece.

2008 ◽  
Vol 140 (4) ◽  
pp. 453-474 ◽  
Author(s):  
David W. Langor ◽  
H.E. James Hammond ◽  
John R. Spence ◽  
Joshua Jacobs ◽  
Tyler P. Cobb

AbstractSaproxylic insect assemblages inhabiting dead wood in Canadian forests are highly diverse and variable but quite poorly understood. Adequate assessment of these assemblages poses significant challenges with respect to sampling, taxonomy, and analysis. Their assessment is nonetheless critical to attaining the broad goals of sustainable forest management because such species are disproportionately threatened elsewhere by the reductions in dead wood generally associated with commercial exploitation of northern forests. The composition of the saproxylic fauna is influenced by many factors, including tree species, degree of decay, stand age, and cause of tree death. Wildfire and forest harvesting have differential impacts on saproxylic insect assemblages and on their recovery in postdisturbance stands. Exploration of saproxylic insect responses to variable retention harvesting and experimental burns is contributing to the development of prescriptions for conserving saproxylic insects in boreal forests. Understanding of processes that determine diversity patterns and responses of saproxylic insects would benefit from increased attention to natural history. Such work should aim to provide a habitat-classification system for dead wood to better identify habitats (and associated species) at risk as a result of forest management. This tool could also be used to improve strategies to better maintain saproxylic organisms and their central nutrient-cycling functions in managed forests.


2019 ◽  
Vol 264 ◽  
pp. 266-282 ◽  
Author(s):  
Antonio D. del Campo ◽  
María González-Sanchis ◽  
Alberto García-Prats ◽  
Carlos J. Ceacero ◽  
Cristina Lull

2020 ◽  
Vol 15 (9) ◽  
pp. 0940a3
Author(s):  
Andrey L D Augustynczik ◽  
Thomas Asbeck ◽  
Marco Basile ◽  
Marlotte Jonker ◽  
Anna Knuff ◽  
...  

Web Ecology ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 61-64 ◽  
Author(s):  
M. Mikoláš ◽  
M. Svoboda ◽  
V. Pouska ◽  
R. C. Morrissey ◽  
D. C. Donato ◽  
...  


2001 ◽  
Vol 7 (2) ◽  
pp. 106-114
Author(s):  
Ela Chraptovič ◽  
Juozas Atkočiūnas

The theory of mathematical programming widely spread as a method of a solution of extreme problems. It accompanies the study of plastic theory problem from its posing up to final solution. However, here again from our point of view not all possibilities are realized. Unfortunately, the use of mathematical programming as an instrument of a numerical solution for structural analysis frequently is also restricted by that. The possibilities of mechanical interpretation of optimality criteria of applied algorithms are not uncovered. The global solution of the problem of mathematical programming exists, if Kuhn-Tucker conditions are satisfied. These conditions do not depend on the applied algorithm of a problem solution. The identity of Kuhn-Tucker conditions with a optimality criteria of Rosen algorithm is finding out in this research. The role of a design matrix for the creating of strain compatibility equations is clarified. The Kuhn-Tucker conditions mean the residual strain compatibility equations in analysis of elastic-plastic systems. It is proved in the article that for problems of limiting equilibrium the Kuhn-Tucker conditions include the dependences of the associated law of plastic flow. The Kuhn-Tucker conditions together with limitations of a source problem of account represent a complete set of dependences of the theory of shakedown. The correct mathematical and mechanical interpretation of the Kuhn-Tucker conditions allows to refuse a direct solution of a dual problem of mathematical programming. It makes easier the solution of optimization problems of structures at shakedown.


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