Much of our understanding of natural forest dynamics in the temperate region of Europe is based on observational studies in old-growth remnants that have emphasized small-scale gap dynamics and equilibrium stand structure and composition. Little attention has been given to the role of infrequent disturbance events in forest dynamics. This study used dendroecological data across an old-growth landscape in the Dinaric Mountains of Bosnia and Herzegovina to examine disturbance history, tree life history traits, and community dynamics. Over all stands, most decades during the past 340 years experienced less than 10% canopy loss, yet each stand showed evidence of periodic intermediate severity disturbances that removed ) 40% of the canopy, some of which were synchronized over the study area landscape. Analysis of radial growth patterns indicated that beech had a significantly longer lifespan than fir, yet fir was able to tolerate longer periods of suppressed growth in shade. Maple had the fasted radial growth and reached the canopy primarily through rapid early growth in canopy gaps. Less shade tolerant species (i.e. maple, ash, and elm) recruited successfully on some of the windthown sites where advance regeneration of beech and fir was less abundant. The results challenge the traditional notions of stability in temperate old-growth of Europe and highlight the non-equilibrial nature of canopy composition due to unique histories of disturbance and tree life history differences.
COBISS.SI-ID: 3712934
Ophiostomatoid fungi can severely affect the health and economic value of Picea abies. There is not much information about the diversity of ophiostomatoid species and their associations with insects in south-eastern Europe. This study aims to investigate the assemblages of ophiostomatoid fungi associated with Ips typographus, Ips amitinus, and Pityogenes chalcographus that infect Norway spruce in Slovenia. Bark beetles were sampled in four phytogeographic regions in Slovenia. The fungi found on the bark beetles were identified based on morphology, DNA sequence comparisons of ITS regions and phylogenetic analysis. The species compositions of the fungi were analysed and the pairwise associations of the occurrence of the fungal species were compared. Thirteen different species were found. The most commonly encountered fungal on the beetles were Ophiostoma bicolor, Ophiostoma brunneo-ciliatum, Grosmannia piceiperda, Ophiostoma ainoae, Ceratocystiopsis minuta, and Grosmannia penicillata. The composition of the fungal associates differed among the bark beetle species, but not among the phytogeographic regions. This study confirms that ophiostomatoid species are common associates of the investigated bark beetle species. Many ophiostomatoid species have strong host associations. I. typographus and P. chalcographus can act as effective vectors for O. bicolor, O. ainoae, G. piceiperda and O.brunneo-ciliatum, whereas I. amitinus often carries G. piceiperda and C. minuta in Slovenian forests.
COBISS.SI-ID: 3689638
Long-term dynamics of uneven-aged dinaric fir-beech forests and corresponding virgin forests in NW Balkan countries (Slovenia, Croatia, Serbia, Bosnia & Herzegovina, and Montenegro) were examined by assessing changes in diameter structure, stand volume, and tree species composition. The parameters were aggregated at the landscape spatial scale, and the intensity of changes in diameter structure and tree species composition was measured by the index of dissimilarity.It was hypothesized that structure and composition of selection forests and virgin forests remained rather stable over several decades. The study revealed pronounced dynamics in the observed parameters. However, these changes were divergent; in most study areas, increases of stand volume and large diameter trees were observed, while the dynamics of silver fir proportion in the total stand volume differed between study areas. Changes in diameter structure and tree species composition of the virgin forests were relatively less pronounced. In uneven-aged forests an increasing proportion of mid-shade tolerant Norway spruce and a constant proportion of light demanding sycamore, which is almost absent in virgin forests, were observed. The great capacity of the selection system to create stands of different structure and composition may be an important advantage in increasingly unpredictable economic, social, and environmental conditions.
COBISS.SI-ID: 3740838
Solid understanding of species’ range and local population densities is important for successful wildlife management and research. Specific behavioural and ecological characteristics make brown bear a difficult species to study. We present a map of range and local population densities of brown bears in Slovenia made with the use of new approach similar to voting classifications based on a combination of four datasets: GPS telemetry data, records of bear removals, systematic and opportunistic direct observations and signs of bear presence, and non-invasive genetic samples. Results indicate that the majority of bears in Slovenia live in Dinaric Mountains in the southern part of the country where local bear population densities exceed 40 bears / 100 km2. This is one of the highest population densities reported so far for this species worldwide. Population densities decrease towards the north (Alpine region) and are very low along the border with Italy and Austria where almost no females are present. This explains slow past and present expansion of this transboundary bear population into the Alps and should be considered in future bear re-colonization management strategies. Results also showed that data from observations and removals overestimate bear population densities at low values, while mortality and genetic data overestimate population densities in areas with more people. Nevertheless, all data types appeared useful for describing the general bear distribution patterns.
COBISS.SI-ID: 2722639
Our study focused on the functional aspects of plant species and vegetation at the transition from larch (Larix decidua Mill.) forest to mountain pine (Pinus mugo Turra) stands on the alpine treeline ecotone. At four different localities in the Slovenian Alps, relevés along an altitudinal gradient and according to vegetation type were made. Species with considerable competitive ability and moderate stress tolerance dominated the upper treeline ecotone, whereas ruderality is poorly expressed. The importance of stress tolerance in plant strategies increased slightly in the mountain pine belt. Changes in dominant life form involved greater cover of chamaephytes and nanophanerophytes in the upper mountain pine belt. Species with evergreen leaves dominated mountain pine stands and deciduous forest stands. The share of species with scleromorphic leaves increased in the direction of the mountain pine belt while the share of species with mesomorphic and hygromorphic leaves declined. Mountain pine stands create good conditions for the regeneration of tree species and colonisation by ecologically more demanding forest species while species of alpine grasslands withdraw on open areas. Since today’s treeline is lowered due to past human activity, an upward shift is expected. Also, considering the great importance of competition strategy, current conditions in mountain pine stands are favourable for future forest succession.
COBISS.SI-ID: 3706790