Summary:

The condition of the continuous existence of the forest ecosystem is the presence of balance of major processes of metabolisms. Each significant change in the chemical balance in the environment brings about disturbances of homeostasis, quantitative and qualitative succession of the major components of both plant and animal world, resulting in degradation of the forest environment. It is necessary to monitor forest environment to control changes in the environment. The network of forest monitoring is based on the fixed observation spots (SPO) of row I and II. Forest monitoring is a system of forest environment evaluation description and sanitary condition on the basis of continuous or periodical observations and measurements of the selected indicators in the observation spots. An additional duty is to fulfill the obligations undertaken by Poland concerning the frame of the Transborder Long Distance Migration of Pollution Convention, Biodiversity Convention, as well as the Strasburg resolution and Helsinki Paneuropean Conference of Ministers called to discuss Forest Protection in Europe, and EU directive Forest Focus Nr 2152/2003. The process of changes and adjustments of the monitoring to the EU demands began in 2004. The state forest monitoring programme introduced then the principle of two-level differentiating of the density of the networks of the Fixed Observation Spots: local and European. Forest monitoring includes tree stands damage monitoring, soils, health state of pine seeds, entomological, phytopathological, pollution deposits, monitoring of under-canopy precipitation and soil solutions. Within the frame of pollution deposits monitoring the concentrations of SO₂ and NO₂ are measured and chemical composition of atmospheric precipitations is described. Chemical analyses comprise the measurements of chemical elements and compounds: Ca, K, Mg, Na, NH₄, Cl, NO₃, SO₄, Al, Mn, and Fe, as well as trace elements. Monitoring investigations may be extended to other substances not included in the Polish Act when spot pollution source imposes a serious burden on the environment. It corresponds mainly to the areas situated in the closest vicinity of industrial plants which may significantly deteriorate the condition of the environment. The plants in interest include: heat and power stations, combustion plants, aluminium works, chemical plants, cellulose works, iron foundries, or industrial and municipal refuse landfill sites. Intensive progress in analytics and chemical apparatus enables detecting and marking of the compounds, including dioxins, occurring at low concentration levels. The paper identifies main dangers posed to the forest environment resulting from emission and migration of polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB) - compounds commonly called dioxins. Mechanisms of biological activity of dioxins are insufficiently investigated. A sequence of unfavorable changes in organisms as a result of exposition to dioxins has been observed. Dioxins reach human and animal organisms together with food, as well as while inhaling and penetrating through skin. Dioxins damage living cells and as a consequence cause growth and development disorders of organisms. A symptom of dioxin intoxication in humans is chloracne (acne chlorica), characterized by disorders in both anatomy and activity of sebaceous glands. The acne symptoms are only signs which indicate a general intoxication with chlorinated hydrocarbons. The effects of dioxins toxicity influence comprise hyperplasia, as well as hyperkeratosis of epidermis between hair folliculi, hyperkeratosis of hair folliculi, as well as scaly metaplasia of sebaceous glands. The paper presents representative results of the investigations obtained within the confines of the introductory dioxin monitoring carried out in the selected forest complexes. Table 1 presents the results of the analysis of forest soil from unpolluted areas (the Antonin Forest Division-Czarnylas Forestry and the Gniezno Division-Orchówek Forestry) and comparison with the results of polluted soil determination collected in the vicinity of Warsaw, where the earlier-conducted investigations showed the general dioxin content at the level of 12.275 ng PCDD/F-TEQ/kg of soil.