Przewidywane oddziaływanie zmian klimatu na ekosystemy leśne oraz ich konsekwencje w urządzaniu lasu

The paper presents the assessment of possible impact of climate change on forest ecosystems in Poland and its consequences in the forest management planning. Scenarios of climate change in the twenty first century do not allow unambiguous determination of the rate and direction of these changes. However, it is believed that climate change could have negative economic con− sequences, which directly or indirectly will affect the deterioration of the environment. Analysis of the possible forms of the impact of climate change on forest ecosystems is particularly relevant in terms of growth conditions. The most noticeable consequences of the changes will concern the threat to the stability of forest stands resulting from the increase in the intensity of trees dieback caused by different factors. The phenomenon results, among others, from: the occurrence of new threats from biotic factors, including caused by secondary pests and the occurrence of alien species of flora and fauna, the severity of the impact of abiotic factors and the deterioration of health (especially of conifers). The increase in the intensity of the evolution of trees is directly related to the size of the cuts contingent and will lead to a blurring of the boundary between thinning and health−cutting. It is expected that the planned size of the cuts will be implemented mainly in the thinning and accidental cuts. This requires the modification of the perception of the rela− tionship of each category cuts. We propose the order and urgency in the planning of forest use. May be supposed that the role of the clearcutting system will be limited, with the exception of some forest complexes of predominantly productive functions, dominated by poor coniferous habitats. It is recommended to use the natural regeneration in the forest management. Lack of clear boundary between thinning and final cutting will require flexibility in the accounting for the total size of cuts. The consequences of climate change will probably occur in the long term perspective. It can therefore be assumed that reasonably forest management can help to reduce their negative effects. This requires pre−emptive decisions in forest management planning and verification for silviculture, production and protection targets, and their consistent implemen− tation.