Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Health status of forest stands on permanent research plots in the Krkonoše Mts. | JOURNAL OF FOREST SCIENCE 56 2010 11 555-569 Health status of forest stands on permanent research plots in the Krkonose Mts. S. Vacek1 K. Matejka2 1Faculty of Forestry and Wood Sciences Czech University of Life Sciences Prague Prague Czech Republic UDS Prague Czech Republic ABSTRACT Damage to beech mixed beech with spruce to spruce with beech and spruce stands in the Krkonose Mts. is described on the basis of evaluation of transition matrices describing the probability of a change in the assessment of defoliation of particular trees in defoliation classes. The condition and development of health status were evaluated in the long run on PRP 1-32 in the Krkonose Mts. by foliage and degrees of defoliation. Features describing the health status of the tree crown damage by snow frost wood-decaying fungi and insects were also evaluated. Average defoliation standard deviation of defoliation estimation of minimum defoliation and frequency of the tree number in defoliation classes were calculated for each plot and each year. Three characteristic periods were distinguished according to different trend of foliage dynamics period of the first symptoms of damage 1976-1980 - a decrease in foliage on average max. by 1 per year period of great damage 1981-1988 - annual defoliation on average around 3-16 period of damage abatement 1989-2009 - annual defoliation on average between 0 and 4 . The incomparably higher resistance of autochthonous stands to air pollution stress culminating in the eighties of the last century was demonstrated unambiguously. Keywords air pollution beech mixed and spruce stands damage defoliation health status Krkonose Mts. transition matrices The first severe damage to spruce stands in the Krkonose Mts. was apparent after climatic disruptions in March 1977 Tesar et al. 1982 . As a result of the air pollution impact accompanied by other negative factors pathogenic organisms and extreme weather conditions the forest suffered an extensive decline. Mainly .
