Ingrowth model validation
Abstract
Frequently, the conversion of forest management from a clear cutting system towards a more near to nature forestry, i.e. management of mixed species forests in continuous cover forestry or minimum intervention sylviculture are intended. However, the “old” planning instruments” like yield tables or production tables are of no help in these cases. They are more and more replaced by individual tree growth simulators, which allow forecasting the development of individual trees, depending on site and their competitive potential. Thus, the long term results of many very diverse forest management options can be roughly evaluated. Such simulators consist of several modules for tree growth (diameter, height, crown size), for mortality and for regeneration. The longer the periods for which forecasts are required, the more important the regeneration modules become. After 50 to 100 years there are hardly trees available that have been measured at the beginning of the simulation experiment, in fact the majority of trees then simulated are such that have been generated by the regeneration module. For the individual tree simulator PROGNAUS instead of a regeneration model, an ingrowth model has been implemented. This module has been developed und parameterised with the data of the Austrian National Forest Inventory. It calculates - depending on site and stand characteristics - the probability for a tree exceeding the minimum recording diameter of 5 cm within the next 5 years. While the PrognAus modules for tree growth and mortality have been validated already several times, the ingrowth module has not yet been evaluated. The thus suggested project aims at validating this module with the data of permanent experiments and observational plots of the BOKU institute of Forest Growth and Yield Research, and if indicated by the results, to improve the module. Having done this successfully, forecasts for longer periods with the simulator PROGNAUS will become more reliable and trustworthy.
keywords Ingrowth
Publikationen
Project staff
Hubert Sterba
Em.O.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Hubert Sterba
hubert.sterba@boku.ac.at
Tel: +43 1 47654-91416
Project Leader
01.10.2010 - 31.10.2012