UDK: 582.475:582.728.4(497.6)            630*44:582.475(497.6) In terms of the health status, in Bosnia and Herzegovina, European silver fir (Abies alba) is currently most threatened by the white mistletoe (Viscum album ssp. abietis). Along with drought and pollution, white mistletoe infestation plays an important role in silver fir decline. The aim of this research was to determine the intensity of infestation of European silver fir trees by the white mistletoe. In order to realize the defined aim, two compartments were chosen in the area of Forest Management Association of Zenica-Doboj Canton and Forestry Office “Olovo” where the analysis of the presence of mistletoe was conducted. In total, 451 fir trees were examined and an assessment of the intensity of infested trees was carried out by implementation of Hawksworth Index of Infestation. According to the results conducted by the research, it was determined that the intensity of infestation of European fir stands differed according to the thirds of crown of the tree. Significant differences were also found in the severity of mistletoe intensity on trees of host trees within the diameter classes. A large number of mistletoe shrubs further deplete the host tree, making it more susceptible to secondary attacks by harmful insects and pathogens.

UDK 582.728.4:630*27(497.6 Sarajevo) This paper has identified the presence of mistletoe (Viscum album ssp. album) on the trees in the urban part of Sarajevo. The mistletoe is a semi-parasitic flowering plant, which grows on a large number of hosts. In general, mistletoes are specialized species, which parasite only on particular trees and shrub species. They cause the dying of different forest species and the decorative trees. As for the forests in Bosnia and Herzegovina, the most important is mistletoe on fir (V. album ssp. abietis), while in terms of fruit trees and trees in urban areas, the mistletoe particularly grow on deciduous species (V. album ssp. album). Researches for the purpose of this paper were effectuated in 2008 in the area of municipality Novo Sarajevo. Mistletoe (V. album ssp. album) has been identified on 37 infected trees, or on 12 species belonging to 5 families and 7 genera. The analysis of number of shrubs in the crowns of infected trees identified the intensity of the infection by this semi-parasitic species. The mistletoe is a primary harmful agent on urban trees and shrubs. Larger number of mistletoe shrubs exhausts the infected host, and it makes the host suitable for the attack by other secondary harmful insects and pathogens. Thus, it is recommended to remove the mistletoe shrubs, even in early stage of development of disease, while the trees are still infected (1-2 shrubs) to a lesser degree.

UDK 630*52:311.2(497.6)          630*52:007.5(497.6) Last decades permanent researches clarify possibilities for forest resource estimation based on terrestrial measurement and remote sensing. The most often the non- parametrical k-NN method is used integrating local estimates from terrestrial measurement and spectral Landsat data. In this paper the weighting functions of the k- NN related to value differences and distances were examined in a case of high forest in site Konjuh in Bosnia. It is found that weighting Euclidean distance has not resulted with efficiency increase. Procentual RMSE's of growing stock showed higher values for weighted estimates on the pixel level. Classified volume estimates on aggregated level compared with volumes from intensive regular forest inventory achieved moderate level of agreement. The agreements between volume estimates are almost perfect regardless on weighting functions. Obtained results point out unweighted estimates as reported in several cases.

UDK 630*92:519.237.8(497.6) According to FAO, the total forest area in Bosnia-Herzegovina amounts 2.709.769 ha or 53,4% of overall state territory. While the total area of private forests is 523.437 ha, private forest ownership is characterized by huge number of small-scale and fragmented individual estates. The aim of this research is to examine how the groups of private forest owners can be created with different clustering methods, regarding different criteria. The data presented in this paper are obtained from PRIFORT project (Research into the Organizations of Private Forest Owners Associations in the Western Balkan Region). Results show that private forest owners in Bosnia- Herzegovina can be grouped in three clusters by using different clustering methods, based on criteria defined in advance. Significant differences in willingness of private forest owners (PFO) to join to their interest associations are noticed for identified clusters. From forest policy aspect, the clusters gathering homogenous groups of private forest owners should be treated by different policy instruments (regulatory, economical or informational) in order to ensure better contribution of private forests to overall economical, ecological and social outcomes expected from forests as the most important natural resources in Bosnia-Herzegovina.

UDK 630*4:712(497.6 Sarajevo) This paper analyzes the health status of trees in the avenues of the city of Sarajevo. Special attention is paid to abiotic harmful influences, snow precipitation and mechanical damage of trees, as the initial factors of destabilization of their health status. Sarajevo area is characterized by a moderate continental climate occurring as a result of the influence of central European climate from the north and the Mediterranean climate from the south and of the variety of the terrain. This type of climate is characterized by hot summers and relatively cold winters. Because of severe thermal influence of the Adriatic Sea autumn is warmer than spring. Distribution of precipitation in Sarajevo is characterized by summer (primary) and autumn (secondary) peaks. Specific weather conditions in this area, in some years, result in early or late snowfall the consequences of which are damages of vegetation cover. The results of this research confirmed significant damages of the trees resulted from the adverse effects of snow in October 2009 (branches fractures, split of the stem and fracture of tree crowns). The resulting injuries are suitable openings for the penetration of rot causing microorganisms (fungi and bacteria) and colonization of insects which is why we can expect further deterioration in the health status of trees in the future. The paper suggests activities the implementation of which can reduce these harmful effects of biotic factors.

UDK 630*44:582.284 (234 Bjelašnica - Igman) U radu se analizira prisustvo rizomorfi gljiva roda Armillaria u dva šumska ekosistema: gospodarskoj šumi i prašumi planinskog kompleksa Bjelašnica – Igman. Objekti istraživanja pripadaju šumama bukve i jele sa smrčom koje su dominantno zastupljene u ukupnom šumskom resursu Bosne i Hercegovine. Ciljevi istraživanja su bili: (1) utvrđivanje intenziteta prisustva rizomorfi Armillaria spp. u tlu istraživanih šumskih ekosistema, (2) analiza značaja prisustva ovih struktura po zdravstveno stanje šuma i (3) razmatranje uticaja gospodarskih mjera na zakonitosti njihove pojave. Prisustvo podzemnih rizomorfi gljiva utvrđivano je na presjecištima kvadratne mreže rastojanja 75 m x 75 m, u tri cilindrična uzorka zemljišta Ø 15 cm, dubine do 15 cm. Pored prisustva rizomorfi, na presjecištima – stajnim tačkama opažano je zdravstveno stanje drveća i grmlja te karakter gospodarskih mjera. Rezultati istraživanja daju uvid u prisustvo rizomorfi u tlu istraživanih objekata i omogućavaju sagledavanje značaja mikrostaništa za bujnost rasta ovih struktura, što je od značaja i za planiranje i za realizaciju gospodarskih mjera u srodnim šumskim ekosistemima.