Naslov
Mathematical-Statistical Apptoximation of the Dispersion of the Time Series of Annual Gross Fellings in the National Forests – the Examples of Croatia, Cwitzerland, Germany and France

Autori
Vuletić, Dijana ; Sabadi, Rudolf

Izvornik
Glasnik za šumske pokuse (0352-3861) 40 (2006); 135-175

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
approximation of the dispersion of annual felling in sustained managed forests of some European countries; the application of logistic and Gompertz´s curves in calculating of time series functions

Sažetak
The possibilities of reliable forecasting of annial felling in the national forests of all types of ownership are being examined in Croatia, Switzerland, Germany and France (in the later the volume felled without fuel wood is beingexamined – comprising annually about 2-3 million m3). Based on time series of annual felling in Croatia (1955-2002), Germany (1984-2991), France (1947-1996, no fuel wood included), and Switzerland (1961-2003), logistic and Gompertz equation the asymptotic values are being calculated. It is known, assuming the consequent application of sustained yield management, that the volume of annual felling is the function of large number of exogenous and endogenous variables. Just to mention few, such as climatic conditions (the appearance of Vivian and Lothar hurricanes in the nineties years of the 20th century), extreme droughts, and similar, marketing conditions (e.g. economic recession or marker recovery) as well as similar factors of forest policy (e.g. when the state starts large scale a forestation or melioration of existing forest stands or numerous other undertakings). The management in the forestrydevelops and becomes visible only after long periods elapsed ; it is thus difficult to say that the volume of timber felled is derermined only by managementplans, already missing or obsolete for large part of existing forest stands. Based on time series of annual felling in Croatia (1955-2002), Germany (1984-2001), France (1947-1996, no fuel wood included), and Switzerland (1961-2003), logistic and Gompertz equation the asymprotic values are being calculated. Practical value of this paper, beside other things, ahould serve as indicator of actually harvested volume. In case of serious divergences with calculated asymprotic values, the causes leading to it should be investigated (climaticdamages, diseases, high or low demand for forest products, their prices, etc.) and eventually elimunated in order to maintain sustainability of the forest management.

Izvorni jezik
Engleski

Znanstvena područja
Šumarstvo

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