Degradation of forest ecosystems became widespread throughout the Northern hemisphere in the 1970's. Research projects were developed to clarify the role of air pollution and changes in climatic conditions by using new monitoring methods. Based
on old traditions and a newborn international cooperative program, a complex monitoring and research project was developed in Hungary to better understand the rapid changes in the forest ecosystems. - (L'A.).
of the natural environment, (especially climate and soils) occuring under the influence of anthropogenic influences and natural mechanisms. A few examples of possible applications of geobotanical indication methods for analysing changes of forest phytocoenoses
and perspectives of scientific cooperation between Poland and USA in research on effects of climatic changes and increasing levels of environmental pollution on forests ecosystems. The remaining articles are connected with forest monitoring, forest gradient studies