Dr. Juergen Nagel
Forest Research Station of Lower Saxony
Department of Growth and Yield
phone: ++49 551 69401 25
fax: ++49 551 69401 60
Bwin 2.5 : Program for Forest Stand Analysis and Prognosis
The development of a flexible single tree growth model is the departments response to the major changes in forest policy mainly changing from even-aged pure stands to uneven-aged mixed forests. In addition, the growth model has an integrating function between the 4 sub-departments.
On the basis of existing data a distant independent version of the growth model was fitted for all important German species. In order to make the growth model useful to practical application the Windows computer program BWIN was written. This program offers besides the growth model routine several routines which are necessary for applied silvicultural simulation.
For easy data storage and handling the program has an implemented data bank. It is possible to import and export ASCII data. Because no forester in the field will measure all the information which is necessary to run a single tree model a data generation procedure was developed. It includes a diameter distribution function, stand height curves, uniform height curves, crown base and crown width functions, as well as several volume functions. Tree coordinates can be generated by using the build in structure generator of PRETZSCH (1993). Thinnings can be carried out in three different routines: [Zielstärkennutzung] (thinning all trees above a certain diameter), A-Value (JOHANN 1982) and interactive on the screen. The stand analysis routines produce output for the single trees, stand table information, diameter height relation, diameter distribution and stand structure parameters. A stand visualization routine helps to graphically interpret the results in pseudo 3d display and stand maps. The visualization routine includes an animation function for stand growth. For easy use there is an on-line help file which covers the use and the theory of the program.
The growth model can handle the major German tree species.
The model designed to help decision making in forest planning,and silviculture