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.

The wild cherry (Prunus avium) has great and multiple importance. The fruits it produces are used for several purposes (as food for people, birds and other animals, as well as in phytotherapy). As many birds and mammals feed on the fruit of the wild cherry, it has the ability of dispersion over large areas in a very short time. It occurs from river deposits up to 1900 m/alt, while it is quite rare in the Submediterranean. Wild cherry grows as a solitary tree or in small groups, usually at the edge of the forest or within the forest in areas with more sunlight. The significance of the wild cherry is reflected in the high economic value of its wood, which makes it much demanded and popular, and thus endangered. The plant material was collected from 22 natural populations in Bosnia and Herzegovina. The fruit and leaves were collected from marginal or solitary trees, usually from the south-facing, outer sun-exposed parts of the tree crown. We measured the following fruit characteristics: fruit length (FL), fruit width (FW), fruit thickness (FT), seed length (SL), seed width (SW), seed thickness (ST), length of the stalk (LOS) and width of the stalk (WOS), and leaf characteristics: length of the petiole (LP), length of the leaf blade (LB), distance from the blade's base to the blade's widest part (BBW), width of the leaf blade (WB), insertion angle of the leaf venation (AV), number of leaf teeth on a 2-cm length (NT), blade width at 1 cm from the blade apex (WBA) and blade width at 1 cm from the blade's base (WBB). All statistical analysis of the data were made using the SPSS 15.0 package for Windows. The results obtained show the presence of a high level of intrapopulation, as well as interpopulation, morphological variability in the natural populations of the wild cherry which have been investigated. Analyses of population differentiation have not confirmed our expectations. Our results only indicate differentiation in the fruit size characteristics, but the indicators are very weak. The resulting high values of the regression coefficient in this research can serve to estimate the values of some features and characteristics without their measurement. The analyses of 16 morphological characteristics in 22 natural populations of the wild cherry in Bosnia and Herzegovina showed statistically significant differences between investigated populations. Differentiation in natural populations of the wild cherry was very low and identified only in fruit dimension characteristics.

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.

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.

The Western Balkan countries: Bosnia and Herzegovina, Croatia, Macedonia and Serbia have in common that their private forests are significant resources for the development of market economy and private ownership. Although the share of private forests varies between 10% (Macedonia) and 47% (Serbia), and probably will increase when the restitution and privatization proces s will have been finished, the private forest owners are almost not represented in national forest policy due to the lack of independent interest associations. Private forest owners' interests are mainly in the hands of public forest administration. In all four countries there are very large numbers of private owners of predominantly small-scaled forests varying between 240, 000 in Macedonia and 800, 000 in Serbia. They are mainly males of an average age of 53 years and most of them live in rural areas in settlements with less than 5, 000 inhabitants. More than one half ofthem are farmers, lower-Ievel employees or unemployed. Regarding education, more than one half of them have high school or vocational college qualifications and one quarter elementary school qualification. The majority of private forest owners have inherited the forests and want to leave them to their children. Most private forest owners hold forest properties smaller than 1 ha. In addition, these properties are often fragmented into 2 to 7 parcels on average, most often in Serbia and Bosnia and Herzegovina. Mixed and coppice forests dominate and volume and annual increment per hectare are modest compared to state forests. The private forests are mainly used for domestic fuel wood and saw log consumption ; tourism, nature conservation and hunting are of minor importanee. Consequently, for about one half of the private forest owners the forest is again, as reflected in its contribution to the household income. In order to increase the efficiency of forest management, all forest owners are prepared to cooperate with other private forest owners, first and foremost in road construction and maintenance. Of second priority is cooperation in forest training for the respondents from Bosnia and Herzegovina, Macedonia and Croatia, and cooperation in sharing harvesting equipment for Serbian respondents. Almost all private forest owners are unsatisfied with the existing situation. They miss extension services of the public forest administrations and state forest enterprises for improving their forest management. Most forest owners miss advice in harvesting, support of road construction and maintenance and advice in silviculture, however, with different priorities in the four countries according to their special needs. Private forest owners are also much concerned that their interests are not appropriately represented in national forest policy by an independent interest association. In particular they expect such an association to fight for provision of financiai inc en tives, tax breaks and reformulation of the existing forest laws in the interest of private forest owners. The respondents suffer from restrictive legal regulations conceming private forest owners. Prescription to pay levies for timber harvests and permissions for harvesting and tree marking by the forest authority before felling are indicated as the most restrictive ones. Although private forest owners' organizations are very rare for the time being, the respondents are well aware about their tasks. The preconditions for the formation of private forest owners' associations for both extension service at the local and regional levels and interest representation at the national level are favourable. Between one and two quarters of the respondents are prepared to engage themselves in the formation of an interest group. They declare to join such an organization voluntarily ifthey may expect either economic advantages or positive performance of the organization or very low membership fee. In each of the four countries there is a critical mass of entrepreneurial forest owners who strongly support an association of private forest owners ; in Bosnia and Herzegovina the "drivers" amount to 55% of the respondents. A majority of two thirds of Bosnian private forest owners also support compulsory membership in accordance with the forest policy decision makers in this country, while the positions of both private forest owners and representatives of institutions in Serbia and Croatia are reserved in this respect. An explanation could be that in Serbia private forest owners' associations at the local level have been developing slowly during the last two years, and Croatia supports their formation by the Forest Extension Service, a department of the public forest administration. In Macedonia compulsory membership is most refused by the representatives of existing private forest owners' associations.

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.

The paper analyses the presence of rhizomorph fungi of the genus Armillaria in two forest ecosystems: the managed forest and the virgin forest of the mountain complex Bjelašnica – Igman. The objects of the study belong to the forests of Common beech and Silver Fir with Norway spruce which are dominantly represented in the overall forest resources of Bosnia and Herzegovina. The objectives of the study were: (1) to establish the intensity of the presence of rhizomorph of Armillaria spp. in the soil of the researched forest ecosystems, (2) the analysis of significance of the presence of these structures to the health status in the forest and (3) analysis of the influence of the management measures to their incidence. The presence of underground rhizomorph fungi was determined at cross correlations of the square network of spacing of 75 m x 75 m, in three cylindrical soil samples of Ø 15 cm, and 15 cm depth. In addition to the presence of the rhizomorphs, at cross correlations – at standing points, we observed the health status of the trees and bushes and the character of the forest management measures. The results of the research give the insight into the presence of rhizomorphs in the soil of the studied objects and allow considering the significance of micro-stands for the trees vigor and the growth of these structures, which is significant in planning and realization of the management measures in generic eco-systems.