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 ...
