Results of the 1999 Forest Condition Survey
2000
Mavsar, R. (Slovenian Forestry Inst., Ljubljana (Slovenia))
The article presents results of the 1999 Forest Condition Survey, carried out on 16 x 16 km grid-net, together with a short review of the 1999 Forest Condition Survey Condition in Murska Suma. The survey sample was comprised of 984 trees on 41 plots. Their average defoliation rate was 24.3 percent, with 29.1 percent of sample trees damaged (trees with defoliation rate higher than 25 percent). The highest average defoliation rate among coniferous trees was observed in the Silver fir (Abies alba Mill.) and in the Chestnut tree (Castanea sativa Mill.) for broad-leaved species. In comparison to 1998 survey, conditions had not significantly changed. Even though both indicators of defoliation rate and rate of damaged trees for the overall sample increased, differences are not significant. Besides defoliation rate, damages of identifiable biotic, abiotic, and antropogenic causes were also listed. Damages of leaves in 28.1 percent of crowns were prevailing due to primary pests, as well as ones of a trunk, in 20.5 percent of trees that were mainly caused by forest activities of cutting and removal. Survey results from Murska Suma present the average defoliation rate of 28.4 percent and the most damaged of tree species, the European oak (Quercus robur L.) with the highest rate of average defoliation.
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