Urządzanie i monitoring lasu a ustalanie stref uszkodzenia lasu i stopni uszkodzenia drzewostanów

In years 1970−2002, in Poland forest damage zones were distinguished within the framework of forest management works. Since 2003 degrees of stand damage have been determined. This study presents basic characteristics of the methods employed for these purposes concerning the necessity to elaborate a new method of determination of degrees of stand damage. The establishment of forest damage zones and degrees of stand damage cannot be treated as one of the forms of monitoring because in order to determine their range, no observations on the permanent plots and – within their confines – on the same sample trees were and are carried out. Over the time, evaluation criteria or/and ways of establishment of the extent of damages have been undergoing considerable and significant methodological changes and modifications. In terms of dynamically altering quantitative and qualitative impact of different factors affecting forest environment, 10 years period of observation repeatability is far too long to use this information as an indicator of occurring changes. In practice, it was and it still is impossible to determine objectively trends and directions of changes taking place in a given object, which is one of the objectives of forest monitoring. The concept of damage zone should be understood not only as an area of grouping the stands of the same or similar damage, but, equally importantly, as those which happen to be under the influence of the same factor exerting its influence at the same level. Therefore, when determining the range of zones, the following three actions should be taken into consideration simultaneously: complex crown evaluation, dendrometric measurements and monitoring of the effect of the causative agent. In order to trace the trends of the changes on the study plots, the same sample trees must be subjected to evaluations and measurements. From the point of view of the time perspective, examinations should be carried out every 5 years (assessment of the crown condition and dendrometric measurements) or on a continuous basis (monitoring of the effect of the causative agent) irrespective of the forest taxation. It is also advisable to consider possible use of contemporary remote sensing techniques to determine the range of zones and degrees of damage, which preliminary can be used to establish the range, intensity and kind of the damages.