SE Slovenia Research Articles

Prezimovališča velikega podkovnjaka <i>Rhinolophus ferrumequinum</i> (Schreber, 1774): podatki iz štirih globokih jam v Sloveniji

In this paper, we present data on not yet surveyed hibernacula of the greater horseshoe bat (Rhinolophus ferrumequinum) from three deep caves in SE Slovenia (Čaganka, Kaščica, Topli vrh 5) and one in W Slovenia. We found between 161 and 255 overwintering greater horseshoe bats in the caves, in addition to six other species. These data show that some deep caves are still unexplored for bats, although bat sightings have been reported in the past. Targeted survey of caves that are harder to access or those from which larger number of bats have been reported from could contribute not only additional distribution data, but also data on higher concentrations of hibernating bats.

Detrital Tourmalines in the Cretaceous–Eocene Julian and Brkini Flysch Basins (SE Alps, Italy and Slovenia)

In the SE Alps, two Cretaceous–Eocene flysch basins, Julian and Brkini, filled with turbidite sediments, are present. This study novelly reports heavy mineral assemblage counts and detrital tourmaline characterization for 11 samples. It is possible to define three different groups, characterized by the presence of (1) a clinopyroxene–epidote–low-ZTR (zircon+tourmaline+rutile; 5%) sample association, (2) a high-ZTR (>48%)–garnet–apatite association and (3) a low-ZTR (<40%)–Cr-spinel–garnet association. Detrital tourmalines from both the Julian and Brkini flysch basins are rather similar in composition, associated with metapelites and metapsammites coexisting or not coexisting with an Al-saturating phase, ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks; however, their number is drastically different. In fact, even if the percentage of heavy minerals is very low and similar in both basins (0.17–1.34% in weight), in the Julian basin, the number of tourmaline crystals is much lower than that in Brkini (1–14 vs. 30–100), suggesting an important change in the provenance area. Interestingly, the presence of a high amount of tourmaline derived from ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks makes these two basins different from all the Cretaceous flysch basins of Bosnia and the Northern Dinaric zone, where these supplies are missing or very limited.

Quantitative and qualitative yield loss caused by red deer (Cervus elaphus L.) grazing on permanent organic grasslands

ABSTRACT This paper addresses yield loss due to red deer (Cervus elaphus) grazing on permanent grasslands on three organic farms in SE Slovenia over two consecutive years. Deer graze on permanent grasslands throughout the year, but the resulting crop loss varies during the growing season. Accounting for three mowings, the quantitative yield loss due to deer grazing totalled 48–52%, or 3.9–4.3 t/ha. Deer had the highest consumption capacity in the spring (first mowing: yield loss of 1.7–1.9 t of air-dried hay/ha), and towards the end of the growing season, consumption decreased (third mowing: loss of 0.9 t/ha). A floristic inventory indicated low species diversity and production in permanent grasslands in SE Slovenia. The crude protein content in unprotected plots was generally greater than that in protected plots, but due to a large quantitative yield loss, the yield of crude protein and net energy for lactation on heavily grazed land were much lower than those on protected land in all mowings. The average additional cost per unit of heavily grazed area ranged from 182 to 344 EUR/ha, and the differences are the result of the different intensities of game grazing in individual locations and grassland production capacities.

Hydrogeological characterization of karst springs of the white (Proteus anguinus anguinus) and black olm (Proteus anguinus parkelj) habitat in Bela krajina (SE Slovenia)

The springs west of Črnomelj, in SE Slovenia, are the habitat of the black (Proteus anguinus parkelj) and the white olm (Proteus anguinus anguinus). Some of these springs are also the only known habitat in the world of endemic species of black olm. A steady decline in olm populations has been observed in this area over the past decades. Owing to the rapid runoff and groundwater flow high-resolution monitoring is essential in providing better insight into the hydrogeological characterization of the catchment area of springs. Specific factors and critical parameters of water behind said olm degradation have not yet been defined. Because the olm’s environment is largely aquatic, one potential critical parameter could be the higher water temperatures (>12 °C) or higher nitrate concentration (>9.2 mg/l). The six-month observation of the springs (July – December 2021) point to water temperature as a potential critical parameter since the water temperature of the springs exceeded 12 °C in months July and August. Nitrate concentrations could also be a second critical parameter in the degradation of the olm’s habitat. Maximum nitrate concentrations above 9.2 mg/l throughout much of the observation period (except for Dobličica spring). Due to less agricultural activity in December in the spring catchment area and a higher dilution rate due to reduced evapotranspiration and increased effective precipitation during this time of the year, the nitrate concentrations are decreased. The results of the measured parameters of groundwater could show the hydrogeological connection between the Otovski and Pački breg springs and between Šotor, Jamnice and Dobličica. The Obršec spring has an independent catchment area. A detailed estimation of the springs catchment area is possible due to a detailed geologic map. It is necessary to determine the origin of the nitrate (nitrate isotope analysis), to quantify the threshold values of the critical parameters, to define precisely all the causes of the olm deterioration, and to make proposals for appropriate measures to limit or even stop the decline of the olm population.

Upper Miocene ostracods from the Krško Basin, SE Slovenia

The purpose of this study was to identify the ostracod assemblage from a 43 m thick section of the Bizeljsko Formation, which constitutes the middle part of the Upper Miocene Posavje Group. The succession comprises sandstone, siltstone, and marlstone, deposited in a delta front environment. The determined ostracods belong to the families Cyprididae, Cytheridae, Darwinulidae, and Loxoconchidae. In total, 30 species were identified. Additionally, 8 morphotypes were determined at the genus level. The most common genera are Candona, Hemicytheria, and Cyprideis. The assemblage belongs to the Caspiocypris labiata subzone from the upper Pannonian. The ostracod assemblage from the Krško Basin is similar in species composition to Pannonian ostracod assemblages from Croatia and Serbia.

Upper Campanian bentonite layers in the Scaglia-type limestone of the northern Dinarides (SE Slovenia)

The research area is located in south-eastern Slovenia and belongs to the eastern extensions of the Slovenian Basin adjacent to the Adriatic Carbonate Platform. The studied section is 25 m thick and consists of grey, brownish and reddish pelagic limestones and calciturbidites, and two bentonite layers 110 and 10 cm thick. Both volcanoclastic horizons consist of greenish, fine-grained muddy material. To date, no other bentonites of similar age are known in the wider Southern Alpine and Dinaridic region. The late Campanian to Campanian/Maastrichtian age of the succession was determined from planktonic foraminifera and calcareous nanoplankton assemblages. XRD analysis revealed the presence of calcite, quartz, muscovite/illite and smectite, which prevails in the clay fraction and is indicative of bentonite clays. We interpret these bentonite horizons as resulting from direct deposition of volcanic ash in a marine environment with a concomitant admixture of detrital material (quartz, muscovite) and later diagenetic carbonatization. The geochemical composition suggests a felsic volcanic origin. The most likely source is the Late Cretaceous–Paleogene bimodal rhyolitic/basaltic volcanism documented along the Sava Suture Zone in present-day Croatia, Bosnia and Herzegovina, Serbia, and North Macedonia. In the Central Apennines three locations with bentonites have been documented. Further spatial and temporal analysis of similar volcanogenic horizons could yield important data on the paleogeographic and tectonic evolution of the Adria/Apulia continental margin.

Prostorska variabilnost sezonske količine padavin v Sloveniji v obdobju 2010–2019

The spatial variability of precipitation in Slovenia was evaluated using correlation decay distance analysis (CDD). CDD analysis essentially explores how the correlation between neighbouring stations varies according to distance. We analysed CDD for the period December 2009–November 2019 using only those meteorological stations (n = 160) with no missing values and operating at same location for the whole analysed period. For each meteorological station, we calculated the threshold distance at which the correlation between series is higher than 0.707 (r2 = 0.5). The results indicate that the highest spatial variability in precipitation is during summer (CDD = 50 km), followed by spring (CDD = 76 km), autumn (CDD = 120 km) and winter (CDD = 141 km), when the spatial variability is the lowest. The spatial variability of precipitation is similar in spring and autumn (with the lowest variability of precipitation in E and SE Slovenia), and it is lowest in S Slovenia in summer and in NW Slovenia in winter. The variogram map indicates anisotropy in the correlation decay distance for spring precipitation. Higher values of semivariance are evident in the NE-SW direction, while semivariance values in the SE-NW direction are much lower.

Alien water lettuce (Pistia stratiotes L.) outcompeted native macrophytes and altered the ecological conditions of a Sava oxbow lake (SE Slovenia)

Introduction of an invasive alien macrophyte water lettuce (Pistia stratiotes L.) radically changed the oxbow lake in Prilipe (SE Slovenia) which has thermal springs that enables the winter survival of this tropical invader. About 10 years after the first record of P. stratiotes, the number, abundance and biomass of indigenous and non-indigenous macrophytes as well as different abiotic parameters were measured. In that period, colonized sections (~94% of the oxbow lake) were completely covered with water lettuce, and the only reservoirs of indigenous macrophyte species were the non-colonized areas (6%). Research in 2011 found only a third of the previously recorded indigenous macrophytes, but then only in small section without P. stratiotes. Three of the species that disappeared were on the Red data list. In the colonized section a higher biomass was observed than in the non-colonized section because of high abundance of water lettuce which remained the only macrophyte. Due to the presence of P. stratiotes, the intensity of light penetrating into the depth and water circulation were reduced, as was the oxygen saturation of the water. In addition to the well documented vegetative propagation of P. stratiotes, a well-established and viable seed bank has been detected in the lake sediment and after winter floods also on lake banks. In the future, special attention should be given to the thermal water ecosystems in temperate climates since they can serve as stepping stones and recruitment centres for the establishment and spread of (sub-)tropical invasive species. Facing predicted climate change such local populations of invasive species can act as stepping stones for further dispersal.

Patterns of tree microhabitats across a gradient of managed to old-growth conditions

An inventory of tree microhabitats was done in two unmanaged forests (Kobile and Ravna gora forest reserves) and one managed beech forest in SE Slovenia. The purpose of this study was to determine the influence of forest management, natural disturbances, and tree characteristics on microhabitat patterns. Forest structure and microhabitats were recorded in systematically placed plots (500 m2 in size) across each area. In total, we inventoried 849 trees on 54 plots and 1833 tree microhabitats. The results showed that forest management had no significant influence on the abundance of microhabitats per tree, but there were differences regarding microhabitat type between managed and unmanaged sites. There were substantially more microhabitats related to standing dead and live habitat trees in unmanaged forest (e.g. woodpecker cavities, insect galleries and bore holes, branch holes, dead branches and fruiting bodies of fungi), whereas in managed forests there were more tree microhabitats related to management (e.g. exposed heartwood, coarse bark, and epiphytic plants). The results also indicate that disturbance, tree diameter, vitality, and species influence the density, diversity, and occurrence of tree microhabitats.

New diploid species in the Ranunculus auricomus complex (Ranunculaceae) from W and SE Europe

The Euro-Siberian complex of Ranunculus auricomus (Ranunculaceae) consists of about 800 mainly apomictic and polyploid taxa. So far, only four sexual species have been described (R. carpaticola Soo, R. cassubicifolius W. Koch, R. notabilis Horandl & Gutermann and R. marsicus Guss. & Ten.). With the exception of R. marsicus and rare autotetraploids of R. cassubicifolius, sexuality seems to be linked to diploidy. Using flow cytometric ploidy estimation, flow cytometric seed screen and pollen quality, six new diploid sexual species have been revealed in C France, C and SE Slovenia and Croatia: Ranunculus austroslovenicus Dunkel, R. calapius Dunkel, R. cebennensis Dunkel, R. mediocompositus Dunkel, R. peracris Dunkel and R. subcarniolicus Dunkel. Here, they are described and depicted in detail. Sexual reproduction has been verified for R. austroslovenicus, R. cebennensis, R. subcarniolicus and also for the previously described R. envalirensis Grau and R. flabellifolius Heuff. ex Rchb.Citation: Dunkel F. G., Gregor T. & Paule J. 2018: New diploid species in the Ranunculus auricomus complex (Ranunculaceae) from W and SE Europe. – Willdenowia 48: 227–257. doi: https://doi.org/10.3372/wi.48.48205Version of record first published online on 24 August 2018 ahead of inclusion in August 2018 issue.

Investigations of the air – ground temperature coupling atlocation of the Malence borehole near Kostanjevica, SE Slovenia

In this paper we present the results of monitoring of temperatures in the air, soil and a borehole V-8/86 at Malence near Kostanjevica in the southeast Slovenia. The results include the temperatures measured in the period from year 2011 to 2015. Highlights of the paper are mainly on the influence of heavy rainfall on temperatures in the upper parts of the shallow subsurface, on understanding how the heat transfers between air and soil and in determination of the warming rate in the shallow subsurface with the assumption that conduction is the prevalent mechanism of heat transfer within the rock. The analysis has shown that heavy rainfall has a greater impact at depth of 1 m in the borehole than at 1 m in the soil, since the sensor at 1 m in the borehole is actually still in the air (inside the borehole) so the rainwater and consequently the air temperature change can reach it faster than the rainwater can infiltrate through soil to depth of 1 m. During infiltration the rainwater's temperature interact with the soil temperature and the change between the rainwater and soil temperatures is no longer evident at 1 m depth in the soil. Based on the measured temperatures from years 2014 and 2015 the rate of warming at the depth of 40 m is 0.011 °C/yr. While analysing the temperature-depth profile of daily means of temperature on the 15th day of each month, we concluded that the influence of seasons can be tracked down to depth of 20 m. At the depth of 20 m temperatures vary within 0.04 °C (2015). The assumption that the conduction is the prevalent mechanism of heat transfer is reasonable, because the theoretical values do not differ much from the measured ones (within 5 %).

SOILS PROPERTIES AND CARBON CONTENT AT RESEARCH OBJECTS IN FIR-BEECH FORESTS ON CALCAREOUS BEDROCKS OF THE DINARIC MOUNTAIN CHAIN: A CASE STUDY FROM SLOVENIA AND BOSNIA

UDK 630*114:630*242(497.6)
 Large areas of European fir-beech forests are characteristic for the Dinaric Mountains and represent one of the most important forest ecosystems in the region. Such forests extend in high karst plateaus from the eastern Alps in SE Slovenia to the N Albanian massifs at the altitudes from 700 to 1200 (1500) m a.s.l. This is the area with a diverse landscape configuration. The bedrock is consisted of limestone, occasionally of dolomite limestone and dolomite. There are various soil conditions, where in a small area, a mosaic of Leptosols, Rendzic Leptosols, Chromic Cambisol, Calcaric and Chromic Luvisols occur. As climate conditions are very favourable for the growth of forests (high precipitation and air humidity), production function of wood is much more emphasized. Very little is known about the long-term effects of forest management and intensity of logging on soil organic matter quality and carbon stocks in these forest soils. Therefore, with an objective to understand better variations in soil properties, both in space and time, aiming to minimize the uncertainties of the SOC (soil organic carbon) and TN (total nitrogen) stocks, we have set up a research objects in silver fir-beech forests, in Slovenia (research plots in Kočevje, Snežnik and Trnovo) and Bosnia and Herzegovina (research plots on MT Bjelašnica). We analysed soil properties of the unmanaged and managed sites studying differences between treatments and also changes for the two years period of observations. Preliminary results from Slovenian sites show that the high intensity of logging (50 and 100% cut of growing stock) causes a decrease in SOC and TN contents, wider C/N ratio and higher pH values, with the largest level of alternations in the organic part of the soils. The study in Bosnia gave information on inherent SOC and TN concentrations in the organic and surface mineral soil, and also indicated no differences in soil properties between unmanaged and managed sites characterized by low (14-18%) intensities of logging.

Estimation of current population status of the Alcon large blue Phengaris alcon (Denis & Schiffermüller, 1775) (Lepidoptera: Lycaenidae) in Bela krajina (SE Slovenia) based on egg counts

An estimate of population size of the endangered Alcon large blue (Phengaris alcon) in Bela krajina (SE Slovenia) was performed based on egg counts. The presence of eggs has been confirmed in all seven currently known populations of the larval host plant Gentiana pneumonanthe in the area. Owing to the short distances between the populations it is probable that the species forms a single metapopulation with an estimated population size of about 190 individuals. One local extinction is documented on a site where P. alcon was present in 2008. We propose conservation measures to preserve the existence of P. alcon in Bela krajina.

Heritage trails through Dolenjska and Bela Krajina in Slovenia: A multi-stakeholder approach to tourism development

One of the crucial methodologies for growing and developing a level of tourism which is sustainable and enhances the totality of local and regional environments is a multi-stakeholder approach to tourism development. In this paper, we present the case of the 'Heritage trails through Dolenjska and Bela krajina in SE Slovenia' in which sustainable rural development (we take this to include cultural & heritage, vinicultural & gastronomic, as well as ecological tourism) is one of the key elements of the integral mix of business economy, viz. development of the region in the SE of Slovenia. The integral approach showed from the very beginning of project activities, within the Novo Mesto chamber of commerce, its long-time implementation until the present, as one of the key products within the tourist destination of Dolenjska, Bela Krajina and Kocevsko-Ribniska. It takes an integrated approach in terms of start-up, implementation and development and is supported by and benefits from the notion of a core of multiple stakeholders.

First record of the European pond turtle Emys orbicularis (Linnaeus, 1758) near Kočevje, SE Slovenia

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Castle Pišece, Slovenia – Building history and wood economy revealed by dendrochronology, dendroprovenancing and historical sources

Castle Pišece, located in SE Slovenia near the border with Croatia, is thought to have been built in the 12th/13th century as one in the line of Salzburg fortresses on the then SE border of the Holy Roman Empire. During thorough restoration that started in 2005, its wooden constructions became accessible for dendrochronological investigations. We collected representative samples from floor or ceiling constructions in most of the rooms in the castle. Dendrochronology helped us to identify felling dates of wood and to propose probable years of reconstructions in 1515, 1578, 1644, 1697, 1752, 1758, 1775 and 1878. The dating showed that the constructions in the presumed Romanesque and Renaissance parts of the building were not as old as expected, whereas those in the supposedly Baroque part of the castle were older than assumed. The selection of wood species used for constructions varied over time. Constructions with end dates 1515–1697 were made of oak (Quercus petraea and Q. robur), those dated to 1752 of silver fir (Abies alba), those dated to 1758 of sweet chestnut (Castanea sativa) and those dated to 1878 of common beech (Fagus sylvatica). Comparison of forestry archives and vegetation in the area showed that most of the timber could have originated from nearby forests; only silver fir had to be transported from sites that were at least 20km away from the castle. Cross-dating of tree-ring series of oak elements with two reference chronologies from Slovenia and two from Austria confirmed the great likelihood that the wood used mostly originated from Slovenia. This indicates that dendroprovenancing, not used in the area before, could also be used SE of the Alps. Both the existing archival documents and dendrochronology indicate that woodworks have taken place every few decades in some periods. The dendrochronological dates can be partly linked to reports on earthquakes (especially the devastating one in 1511), rebellions and year marks carved on the stone plaques.

Oviposition preferences of a threatened butterfly Leptidea morsei (Lepidoptera: Pieridae) at the western border of its range

The oviposition preferences of Leptidea morsei at the western border of its range (SE Slovenia) were studied with the aim of integrating this information into species habitat management recommendations. The characteristics of egg-laying habitat were examined at the landscape, patch, plant and leaf levels. Because sightings of adults in the field were infrequent, intensive searching for previously laid eggs on Lathyrus niger plants was chosen as the survey method. The main oviposition habitats of L. morsei in Slovenia were found to be the forest edges and light stands of thermophilous oak, oak-hornbeam and mesic beech forests (landscape level). The egg-laying sites were L. niger plants growing individually or in small stands, and oriented mostly towards W, SW, and S. The oviposition plants were between 33 and 120 cm high, with those growing in half to full shade preferred. Eggs were deposited singly, mainly on the underside of leaflets of terminal leaves, located mostly on the top quarter of plants irrespective of their height and growth form. The most important factors affecting egg-placement are sun exposure and the size of L. niger stands at ovipositing sites (patch level), leaf exposure on the plant in vertical and horizontal directions (plant level), leaf age and the leaf parts where the risk of leaf and egg desiccation is lower (leaf level). Management strategies for the main egg-laying habitats of the species are proposed.

The effect of different entomopathogens on white grubs (Coleoptera: Scarabaeidae) in an organic hay-producing grassland

In 2011, a field block trial examined the biological control of white grubs of June beetle (Amphimallon solstitialis), margined vine chafer (Anomala dubia) and garden chafer (Phyllopertha horticola) on a permanent cut grassland in Gotenica (SE Slovenia). The efficacy of Beauveria brongniartii, Beauveria bassiana, Bacillus thuringiensis var. kurstaki and Heterorhabditis bacteriophora in the form of water suspension and infested grain was tested against a control treatment. The initial number of white grubs (April 12; 39 white grubs/m2) was reduced with all tested entomopathogens up until the third evaluation (May 26; 32 white grubs/m2). However, the studied treatments were not sufficient to reduce the white grub population in the soils below the economical threshold (20 individuals/m2). The average number of white grubs was affected mostly by the treatment where the active ingredient was B. thuringiensis var. kurstaki. With one application in April, only the abundance of overwintered white grubs was reduced. To decrease the summer generation of white grubs, an application of biological agents is also required at a later time. The 8% higher dry matter yield at the first cut (June 10) compared to the second cut (September 6) provided evidence for the prior statement.

Development of slope and related subsoil karst: A case study from Bela Krajina, SE Slovenia

The relief of Bela Krajina and Semiška Reber in southeastern Slovenia is mainly a consequence of post Late Miocene tectonic movements and karstic, mostly subsoil, erosion. In the lower half of the slope at Vrtača in the northwestern part of Bela Krajina, 1.3 km northeast of the center of Semič and 15 to 25 meters above the surroundings, a 250-meter long and about 150-meter wide lateral ridge rises at an inclination of 8°. The formation of the medium-sized relief between the elevated lateral ridge and the lower elongated side depressions is most probably to a large extent the consequence of differences in the rock fissuring and the varying intensity of hundreds of thousands of years lasting corrosion related to it. Traces of subsoil formation are the prevailing feature found on hundreds of rock ribs (i.e., subsoil rock formations that are not cone-shaped like teeth but rather elongated with their longer axes largely parallel to the dip of the surface) dissecting the surface area of one of the vineyard plots on the rocky lateral ridge. This indicates they were relatively recently exposed, as a consequence of human activity when soil was removed from an abandoned plot.

Conservation assessment of the butterfly fauna along the River Sava between Krško and the state border

An inventory of butterfly fauna was carried out in 2008 within the southern part of the Ecological Important Area »the Sava River between Radeče and the state border with Croatia« with the aim of evaluating the most important areas for butterflies. Butterfly fauna was surveyed within a study area of 32 km2, using the transect method. Twenty-one combined habitat types were included in the transect lines, with a total length of 19.2 km. The following parameters were used to evaluate the conservation importance of the combined habitat types: species richness of the combined habitat type, population density of species in combined habitat type, total population density of combined habitat type, maximum population density of species in combined habitat type, number of species with maximum population density in combined habitat type, number of threatened species in combined habitat type and number of threatened species with maximum population density in combined habitat type. A total of 69 species of butterflies (38% of Slovene butterfly fauna) were recorded, 10 of which are threatened on national or European level. The most important combined habitat types for butterflies are extensively managed dry grasslands, abandoned dry grasslands, some types of semi-intensively used grasslands, some types of ruderal communities, and dry woodland rides and edges.On the basis of the distribution of the most important combined habitat types in the study area, four important areas for butterflies were designated, with a total area of 6.6 km2. They are important for preserving threatened species, ecological specialists and other rare or locally distributed species in the sub-pannonian part of SE Slovenia.