Changes of forest health – based on data of forest healt monitoring systems

Abstract

Hungarian forest condition monitoring networks and methods are well joined with European systems. Results of yearly observations can be followed health condition of forests and the main different forest tree species. Since 1989 „National Intensive Monitoring System” (EVH) gives detailed data in this topic. Data of defoliation and discolouration showed, Hungarian forests health are somewhat better than European average. Apart from this local considerable forest damages can appear in Hungary in certain years. Primary reasons of forest diseases are extreme climatic situations that decrease the natural resistance of the forests, so they become more sensitive to different pathogens.
According to data of monitoring systems most of the forest damages are caused by direct abiotic reasons, (25–30 thousand hectares per year are involved). Identifiable biotic damages occur approximately 100–150 thousand hectares every year. Sum up results of the last 16 years observations, data show, consider of yearly fluctuation, the health condition of Hungarian forests are adequate. Nevertheless in the last fifteen years the most important damage types show slow increase of value.