Šume su kaotični nelinearni dinamički sustavi, što znači kako im se stanje mijenja sukladno pravilima koje diktiraju zakoni prirode.
Autori istražuju disipativno stanje, brzinu rasta i produkciju sastojina hrasta lužnjaka (Quercus robur L.) u gospodarskoj jedinici Slavir. Tijekom istraživanja primjenjuju Teoriju nelinearnih dinamičkih sustava i Teoriju disipativnih struktura. Kompleksnim jednadžbama rasta i razvoja debljinske i visinske strukture analiziraju stanje i brzinu rasta sjemenjača hrasta lužnjaka. Teorijom o disipativnim strukturama klasificirane su sastojine na: ravnotežne, periodične, neperiodične i kaotične. Disipativne šume, u ravnoteži, blizu ravnoteže i daleko od ravnoteže.
Pojam disipativna struktura uveo je belgijski kemičar i fizičar Ilyje Prigogine, kako bi objasnio koherentno ponašanje u sustavima daleko od stanja ravnoteže. Njime se objašnjava uska povezanost između strukture i reda na jednoj i disipacija na drugoj strani. Teorija disipativnih struktura govori o kretanju od reda prema neredu i sve većoj entropiji. Prema drugom zakonu termodinamike, dok entropija raste, energija se gubi ireverzibilno. Rasipanje energije koje je ireverzibilno na molekularnoj razini prati suprotan proces uređenog kaosa na subatomskoj razini. Prema Prigoginu, disipativne strukture su otoci reda u moru nereda, održavajući i povećavajući svoj red na način da povećavaju nered svojeg okruženja.
Izrađena je karta disipativne strukture sjemenjača hrasta lužnjaka (Quercus robur L.) za gospodarsku jedinicu Slavir. Za I. bonitet konstruirani su standardni nizovi visina, a za svako stanje sastojina iteracijama dobiveni su parametri regresijskih nizova tečajnog godišnjeg debljinskog prirasta. Za disipativnu strukturu sastojina konstruirane su volumne prirasno-prihodne tablice i tablice novčane vrijednosti drvnih sortimenata na I. bonitetu.
Signifikantne su razlike u produkciji i novčanoj vrijednosti drvnih sortimenata za disipativnu strukturu hrasta lužnjaka (Quercus robur L.).
Mlade sastojine u fazi prvih kulminacija prirasta, do 20 godina starosti, površine 1204 ha u disipativnoj strukturi su početno stanje. Karakteristična značajka kaotičnih sustava je njihova osjetljiva ovisnost o početnim uvjetima.
I najmanji biotički i abiotički poremećaj može prouzročiti nelinearni povratni učinak.Forests are chaotic nonlinear dynamic systems, whose condition changes in accordance with the patterns dictated by the laws of nature.
The authors investigate the dissipative condition, growth rate and production of pedunculate oak stands (Quercus robur L.) in the management unit Slavir. They apply the Theory of Nonlinear Dynamical Systems and the Theory of Dissipative Structures in their research. Using complex equations of growth and development of diameter and height structures, the authors analyze the condition and speed of growth of pedunculate oak high forests. According to the Theory of Dissipative Structures, stands are classified into the following categories: balanced, periodic, non-periodic and chaotic. Dissipative forests are equilibrium, near-equilibrium and far-from-equilibrium systems.
The concept of dissipative structures, coined by the Belgian chemist and physicist Ilya Prigogine, accounts for the coherent behaviour in far-from-equilibrium systems. This concept explains a close link between structures and order on the one hand and dissipation on the other. The Theory of Dissipative Structures deals with a tendency from order towards disorder and increasing entropy. According to the Second Law of Thermodynamics, while entropy increases, energy is lost irreversibly. Energy dissipation, which is irreversible at the molecular level, is followed by an opposite process of orderly chaos at the subatomic level. According to Prigogine, dissipative structures are islands of order in the sea of disorder. They maintain and increase their order by increasing the disorder of their surroundings.
A map of a dissipative structure of pedunculate oak (Quercus robur L.) high forests was made for the management unit Slavir. Standard height series were constructed for the first site class. Parameters of regression series of current annual diameter increment were obtained by iterations for each particular stand condition. Volume yield tables and tables of monetary values of wood assortments in the first site class were constructed for the dissipative stand structure.
There are significant differences in the production and monetary value of wood assortments for the dissipative structure of pedunculate oak (Quercus robur L.).
Young stands aged 20 and less in the phase of first increment culminations, covering areas of 1,204 ha and having a dissipative structure, denote the initial condition.
A characteristic feature of chaotic systems is their sensitive dependence on initial conditions. Even the slightest biotic and abiotic disturbance may cause a nonlinear retroactive effect.
Stands in a balanced condition over 621 ha are predominantly young and cannot be compared to older stands in a periodic, non-periodic and chaotic condition.
The stands in a periodic condition extend over 1,295 ha. Their density is 0.86, the increment amounts to 7.10 m3/ha, the average stock is 347.7 m3/ha and the monetary value of wood assortments is 156,441 kuna per hectare.
The stands in a non-periodic condition cover an area of 3,720 ha. Their density is 0.86, the increment is 6.71 m3/ha, the average stock is 352.2 m3/ha and the monetary value of wood assortments is 162,450 kuna per hectare.
The stands in a chaotic condition cover an area of 1,004 ha. Their density is 0.80, the increment is 5.61 m3/ha and the average stock is 352.8, whereas the monetary value of wood assortments amounts to only 65,048 kuna per hectare due to dieback.
The research results are a pathway to modeling multi-dimensional forest dynamics, which leads to multipurpose and sustainable management
