1. Proximity to riverbed influences physiological response of adult pedunculate oak treesLazar Kesić, Matjaž Čater, Saša Orlović, Bratislav Matović, Marko Stojanović, Mirjana Bojović, 2023, original scientific article Abstract: The pedunculate oak (Quercus robur L.) is economically and ecologically one of the most significant tree species in Serbia, however, little is known about the influence of the riverbed distance and its water supply on ecophysiological responses of this species. Given the limited information on the light-response curve of photosynthesis for oaks in southwest Srem, Serbia, the aim of this paper is to enhance understanding of their ecophysiological responses in this context. Maximum assimilation rate (Amax), the quantum yield (Ф), and light compensation point (LCP) were compared in adult trees situated along the transect from the river: (1) close to the river, (2) intermediate, (3) farthest from the river, and (4) forest reserve (second closest), with the first three transects being managed forests and the last one being an unmanaged forest reserve. The measurements were conducted in July during the first evidence of drought. The highest Amax rates were measured in all light intensities on the site closest to the river and the smallest on the site that was most distant to the water source. The most efficient were trees close to the river and the ones in the forest reserve. No significant difference between compensation points was confirmed for the studied groups of trees, although the forest reserve trees showed slightly higher values. The results demonstrated clear response between transects, which followed the distance from the riverbed. Pedunculate oak's reliance on groundwater is in tight relation with ecophysiological processes in trees; groundwater depletion may threaten its survival in areas distant from the river. Keywords: Quercus robur L., floodplain forest, drought, light-response curves, transects Published in DiRROS: 05.06.2024; Views: 1363; Downloads: 164 Full text (861,11 KB) This document has many files! More... |
2. Tubakia spp., Didymella macrostoma and Apiognomonia errabunda causing leaf spot and anthracnose of Quercus robur in the Mura-Drava-Danube Biosphere ReserveMilica Zlatković, Marcus Sallmannshofer, Silvio Schueler, Thomas L. Cech, Milutin Djilas, Gernot Hoch, Katharina Lapin, Nikica Ogris, Barbara Piškur, Katharina Schwanda, Srđan Stojnić, Marjana Westergren, Saša Orlović, 2024, original scientific article Abstract: The Mura-Drava-Danube transboundary UNESCO Biosphere Reserve represents one of the best-preserved wetlands in Europe. The Reserve’s riparian forests play a significant role in ecosystem functioning and pedunculate oak (Quercus robur) is one of the keystone species of these forests. In recent years, pedunculate oak trees in the Reserve displayed symptoms of necrotic lesions on their leaves. The lesions varied in size, from small, circular to irregular reddish brown to grayish spots to larger necrotic areas that resembled leaf anthracnose and extended along the leaf nerves. In 2021, symptomatic leaves were collected in three countries of the Reserve, i.e. Austria, Slovenia, and Serbia to identify the causative agents of these diseases. Fungal cultures were obtained from symptoms and identified using morphology and multilocus phylogenetic analyses of the ITS rDNA, partial LSU rDNA, tef 1-α, BT2, CAL, ACT, and RPB2 genes. The fungi were identified as Tubakia dryina, Tubakia sp. (Tubakia dryinoides sensu lato), Didymella macrostoma, and Apiognomonia errabunda. Pathogenicity tests done by inoculating the leaves of one-year old pedunculate oak plants revealed that the isolated fungi caused symptoms as those seen in the forest. To our knowledge, this study represents the first report of D. macrostoma as the cause of pedunculate oak leaf spot disease in Serbia and worldwide. It is also the first finding of Tubakia leaf spot disease of pedunculate oak caused by T. dryina in Austria and Serbia. Moreover, Tubakia sp. was proven to be another causative agent of Tubakia leaf spot disease. Additionally, oak anthracnose caused by A. errabunda was found for the first time on pedunculate oak leaves in Austria and Slovenia. During the past decade, pedunculate oak trees have been facing increasing threats from multiple abiotic and biotic factors which has resulted in decline and absence of natural regeneration of these trees. The results of this study add to the understanding of the contributing factors to the decline of pedunculate oak in riparian forests and are important for the development of management strategies to counteract this decline. Keywords: Mura-Drava-Danube Biosphere Reserve, riparian forests, Tubakia leaf spot, Didymella macrostoma, oak anthracnose, pedunculate oak, leaf spot diseases Published in DiRROS: 23.04.2024; Views: 414; Downloads: 210 Full text (3,10 MB) This document has many files! More... |
3. Forest managers’ perspectives on environmental changes in the biosphere reserve Mura-Drava-DanubeMarcus Sallmannshofer, Rok Damjanić, Harald Vacik, Marjana Westergren, Tjaša Baloh, Gregor Božič, Mladen Ivanković, Gyula Kovács, Miran Lanšćak, Katharina Lapin, Laszlo Nagy, Silvija Krajter Ostoić, Saša Orlović, Srđan Stojnić, Peter Železnik, Milica Zlatković, Silvio Schueler, 2023, original scientific article Abstract: Riparian forests are particularly vulnerable to environmental change and anthropogenic influences because they are highly dynamic ecosystems, thus proper adaptation measures are crucial. The implementation of these measures, however, strongly depends on the actors’ perceptions of the specific problems occurring in such forests. For understanding the constraints of specific interest groups toward different adaptation activities, information in this field is essential. By conducting a questionnaire survey we explore how different types of forest managers, i.e., forestry professionals, forest owners, and conservation managers, perceive the effects of environmental change on forest management in the recently established Transboundary Biosphere Reserve Mura-Drava-Danube. We show that these forest managers are highly aware of ongoing environmental changes and appraise deteriorating forest conditions, especially after observing changes themselves. Abiotic damage is expected to increase the most, followed by biotic damage, the spread of non-native species, and tree dieback. Nearly 80% of the survey respondents expect further changes and almost all of them intend to adapt their management of forests to mitigate or prepare for these changes. Nevertheless, we show differences in sensitivity to change and willingness to initiate adaptation actions by assessing adaptation thresholds: conservation managers appear generally more tolerant to changes, which results in higher thresholds to initiate management adaptation than forestry professionals Keywords: biosphere reserve Mura-Drava-Danube, forest management, sensitivity to environmental change, stakeholder perception, adaptation thresholds, riparian forest tree species Published in DiRROS: 31.05.2023; Views: 703; Downloads: 501 Full text (2,00 MB) This document has many files! More... |
4. Turkey oak (Quercus cerris L.) is more drought tolerant and better reflects climate variations compared to pedunculate oak (Quercus robur L.) in lowland mixed forests in northwestern Serbia : ǂa ǂstable carbon isotope ratio (δ13C) and radial growth approachSaša Kostić, Tom Levanič, Saša Orlović, Bratislav Matović, Dejan Stojanović, 2022, original scientific article Abstract: Tree-ring width (TRW), stable carbon isotope ratio (δ13C) and intrinsic water use efficiency (iWUE) data set chronologies were built for the period 1961–2000 for two oak species (pedunculate oak – Quercus robur L. and Turkey oak – Quercus cerris L.) in northwestern Serbia (Vojvodina province). We focused on the response of the two oak species to measured meteorological data (temperature, precipitation and cloud cover), drought events expressed by six meteorological drought indices, and river water level to better understand their drought tolerance and stress and to assess the reliability of the species response to climate and drought indices when using TRW or δ13C. Turkey oak exhibited better drought tolerance (and less drought stress) compared to pedunculate oak, as manifested, respectively, by less negative δ13C and lower iWUE values. Based on a generalised additive mixed model (GAMM) among the six drought indices studied, the standardised precipitation evapotranspiration index and the standardised precipitation index showed the best fit with both TRW and δ13C, while the Palmer drought severity index exerted a strong influence only on TRW. It was thus concluded that δ13C responds more strongly and rapidly to climate variations than TRW. Keywords: dendrochronology, stable carbon isotope, tree ring, Quercus robur, Quercus cerris, drought, climate change Published in DiRROS: 04.08.2022; Views: 900; Downloads: 702 Full text (5,19 MB) This document has many files! More... |
5. Ectomycorrhizal fungal community in mature white poplar plantationMarina Milović, Saša Orlović, Tine Grebenc, Marko Bajc, Branislav Kovačević, Hojka Kraigher, 2021, original scientific article Abstract: Ectomycorrhizal communities are rarely studied on seasonal basis, especially in poplar plantations. In this study we analysed the ectomycorrhizal community in a mature twenty-year-old white poplar (Populus alba L.) plantation during four consecutive seasons. Using morpho-anatomical and molecular identification 30 taxa of ectomycorrhizal fungi were recorded of which 15 were identified to the species level, 12 to the genus level, 2 to the family, and one morphotype of ectomycorrhizae remained unidentified. The most abundant among identified ectomycorrhizal fungi were: Inocybe griseovelata, Inocybe splendens, Tuber rufum, and Tomentella sp. 2, which together represented up to 50% of all ectomycorrhizal root tips. The number of ectomycorrhizal fungal taxa and the percentage of vital ectomycorrhizal root tips were highest in winter and spring, respectively. The diversity indices of ectomycorrhizae, number of vital ectomycorrhizal root tips, and total fine roots in the studied poplar plantation did not differ between seasons. Ectomycorrhizal fungi belonging to Inocybaceae family and the short-distance exploration strategy were dominant in all four seasons. On the other hand, the abundance of ectomycorrhizal root tips belonging to the medium-distance exploration strategy type was significantly higher in spring in comparison with autumn and winter. Keywords: Populus alba L., Ectomycorrhizal diversity, morpho-anatomical characterization, molecular identification, seasons Published in DiRROS: 03.12.2021; Views: 1136; Downloads: 565 Full text (847,82 KB) This document has many files! More... |
6. |
7. |
8. Comparing environmental impacts of alien plants, insects and pathogens in protected riparian forestsKatharina Lapin, Sven Bacher, Thomas L. Cech, Rok Damjanić, Franz Essl, Freya-Isabel Georges, Gernot Hoch, Andreja Kavčič, András Koltay, Saša Kostić, Ivan Lukić, Aleksander Marinšek, Laszlo Nagy, Sonja Novak Agbaba, Janine Oettel, Saša Orlović, Leopold Poljaković-Pajnik, Marcus Sallmannshofer, Martin Steinkellner, Srdjan Stojnić, Marjana Westergren, Milica Zlatković, Anita Zolles, Maarten De Groot, 2021, original scientific article Abstract: The prioritization of alien species according to the magnitude of their environmental impacts has become increasingly important for the management of invasive alien species. In this study, we applied the Environmental Impact Classification of Alien Taxa (EICAT) to classify alien taxa from three different taxonomic groups to facilitate the prioritisation of management actions for the threatened riparian forests of the Mura-Drava-Danube Biosphere Reserve, South East Europe. With local experts we collated a list of 198 alien species (115 plants, 45 insects, and 38 fungi) with populations reported in southeast European forest ecosystems and included them in the EICAT. We found impact reports for 114 species. Eleven of these species caused local extinctions of a native species, 35 led to a population decrease, 51 to a reduction in performance in at least one native species and for 17 alien species no effects on individual fitness of native species were detected. Fungi had significantly highest impact and were more likely to have information on their impacts reported. Competition and parasitism were the most important impact mechanisms of alien species. This study is, to our knowledge, the first application of EICAT to all known alien species of several taxonomic groups in a protected area. The impact rankings enabled to identify taxa that generally cause high impacts and to prioritize species for the management in protected areas according to their impact magnitudes. By following a standardized impact protocol, we identified several alien species causing high impacts that do not appear on any expert-based risk list, which are relevant for policymakers. Thus, we recommend that alien species be systematically screened to identify knowledge gaps and prioritize their management with respect to spatio-temporal trends in impact magnitudes. Keywords: alien species, biological invasions, EICAT, invasive species management, protected areas, species prioritization Published in DiRROS: 29.10.2021; Views: 1174; Downloads: 834 Full text (1,13 MB) This document has many files! More... |
9. |
10. Ectomycorrhizae of Norway spruce from its southernmost natural distribution range in SerbiaMarina Katanić, Saša Orlović, Tine Grebenc, Marko Bajc, Saša Pekeč, Milan Drekić, Hojka Kraigher, original scientific article Abstract: Norway spruce (Picea abies Karst.) reaches its southernmost limit in the mountainous regions of south Serbia and Bulgaria. The species is a regionally important timber species for the wood industry and a significant host for various ectomycorrhizal fungi, including edible species. We analysed ectomycorrhizal community and fine root parameters of high continental / subalpine Norway spruce stands at three sites (Stara planina, Kopaonik, Tara) located in protected areas in Serbia. In addition, we assessed the potential effects of altitude and growing season on the ectomycorrhizal diversity and fine root parameters. Using standardised sampling in combination with morpho-anatomical and molecular identification of ectomycorrhizae, we recorded 29 different anatomorphotypes. None of the identified fungi belonged to commercial edible fungal species. Compared to other Norway spruce ectomycorrhiza studies in central Europe, sites in Serbia exhibited lower species diversity and different dominant species composition, with Cenococcum spp. and Russula spp. as the dominant ectomycorrhizal fungi. A number of ectomycorrhizal types and the value of the species richness index differed between Stara planina and Tara in the autumn, but the influence of site and season on the studied diversity indices was not significant. The total number of fine roots increased in the spring, while percentage of vital ectomycorrhizal root tips increased in the autumn. This study was the first examination of Norway spruce ectomycorrhizal communities at the edge of the natural geographical range of the species. Keywords: ectomycorrhiza, Picea abies Karst, community structure, fine roots Published in DiRROS: 22.01.2019; Views: 2964; Downloads: 1778 Full text (553,32 KB) This document has many files! More... |