A timber harvesting model for Austria

Between 1981 and 1985 the Austrian National Forest Inventory (ANF) establis hed a set of 5500 clusters, each with four permanent plots covering all Aus trian forests. After the first remeasurement between 1986 and 1990 models w ere developed to predict tree growth, mortality and the behavior of forest owners in harvesting timber. A set of logistic equations describes the prob ability for a given stand to exhibit intermediate harvesting, single-tree s election or final clear cutting. Independent variables were either continuo us or categorical, describing: (i) regional units such as provinces, (ii) t ypes of ownership (groups of ownership sizes), (iii) site factors (elevatio n and slope), and (iv) stand characteristics (species mixture, density, mea n diameter). Timber removals on the plots are recorded by five relative dia meter at breast height (dbh)-classes. Removal percentages differ by elevati on, harvesting categories, and tree species groups. Timber harvest forecast s and their spatial arrangement over Austria in the following four 5-year p eriods were made available to the public using computer software. In 1997 d ata of the second inventory remeasurements were available and thus the fore casts for this period could be evaluated. When forecast units are large eno ugh, deviations from the model are either small or can be explained by a di fferent timber market scenario and/or a general socio-economical scenario. (C) 2000 Elsevier Science B.V. All rights reserved.