Utilizing permanent sampling plots for inventory and planning in a forest district with clear cut-free management.

This paper contributes to the development of new inventory and planning met hods for the transformation of evenly aged forest stands by picking out imp ortant aspects concerning timber volume, growth, and harvesting possibiliti es. A more complete discussion of the results with regard to forest mensura tion and yield science has been presented by TOLLE and BAUSTIAN (1999). Periodical assessments of forest stands based on permanent sampling plots c an particularly aid the tree wise comprehension of the stand development. A nalyzing the results of such an assessment can lead to strategies how to tr ansform evenly aged, evenly structured stands into structurally rich and st able forests. Those forests will be permanently stocked and proper manageme nt practice will make clear cutting obsolete. The study area is a forest di strict within the Forest enterprise of Eitorf in North-Rine Westfalia and h as been managed without clear cutting for 20 years. In 1988, permanent samp ling plots (Fig. 1 and 2) have been set up. The dimensions, positions and s pecies of the trees within the plots were assessed in 1988, 1993, and 1998 (Tab. 2, 3, 4 and 5). The results were compared to those of the forest mana gement results for 1988 and 1998 (Tab. 3 und 5). It could be shown that a p eriodical assessment of permanent sampling plots provides a sound database for the transformation of evenly aged stands, an aim that has been introduc ed into the silvicultural programs of many forestry commissions. The method delivers necessary information for the prediction of timber volume, growth and harvesting possibilities that are otherwise difficult to obtain for st ructurally rich forests.