Bioecology of mistletoe (Viscum album ssp. Abietis) and its role in the process of deterioration and desiccation of the European fir (Abies alba Mill.) in the western part of the Republic of Srpska [Bosnia and Herzegovina]. [Doctoral dissertation] | Bioekologija bele imele (Viscum album ssp. Abietis) i njena uloga u procesu propadanja i sušenja jele (Abies alba Mill.) u zapadnom djelu Republike Srpske [Bosna i Hercegovina]. Doktorska disertacija

Research presented in this work was conducted in mixed stands of beech and fir, and beech and fir with spruce in Republic of Srpska. 15 stands with size of 0.25ha were encompassed. Stands were classified by elevation zones (400m; 600m; 800m; 1000m and 1200m). Besides that, in each elevation zone stands were classified by canopy density (scattered, full and dense). Geologic substrate was made of silicates and limestone, where various types of soil were formed. Climate of the area researched has the attributes from temperate-continental on the lowest slopes to the mountain type on the highest elevations. According to acquired results of the research, intensity of the mistletoe contamination of the fir trees classified by elevation zones is: 400m 32.5%, 600m 23.5%, 800m 26.5%, 100m 17.0% and 1200m 0.5%. Intensity of contamination depend on the canopy density is scattered 30.2%, full 16.9% and dense 8.9%. Due to establish the degree of viality of the fir trees we conducted the evaluation of: desiccation index, degree of defoliation and degree of decolorization. Loss of the diameter increment (id) of the trees that are contaminated with mistletoe relating to healthy trees is: trees contaminated with mistletoe 24.1%, trees with wounds 29.8%, trees with mistletoe and wounds 30.3%. For the purposes of the research 13 trees were cut down on all three macro localities, total of 39. On those trees the real number of mistletoe bushes was determined. According to those results we can state that the biggest average number of bushes for the group IV was 1314 by one tree, and this were registered on the locality Vucija Poljana. The highest number of the mistletoe bushes was found in the upper third of crown, and the smallest in the first third. During this research on the mistletoe bushes 5 species of the noxious insects were found: Psylla visci, Carulaspis viscid, Agrilus viscivorus, Pogonochaerus fasciculatus, Synanthedon loranthi. Some of those species can be successfully used for biocontrole of the mistletoe. Besides this, during this research 35 species of fungi that have importance in biocontrole of the mistletoe were found: Cytospora sp., Gleosporium harposporum, Phoma viscid, Phyllosticta viscid, Septoria viscid, Sphaeropsis viscid and eventually Gibberidea viscid.