21. Contrasting resource dynamics in mast years for European Beech and Oak - a continental scale analysisAnita Nussbaumer, Arthur Gessler, Sue Benham, B. De Cinti, Sophia Etzold, Morten Ingerslev, Frank Jacob, François Lebourgeois, Tom Levanič, Hrvoje Marjanović, 2021, original scientific article Abstract: Resource allocation to different plant tissues is likely to be affected by high investment into fruit production during mast years. However, there is a large knowledge gap concerning species-specific differences in resource dynamics. We investigated the influence of mast years on stem growth, leaf production, and leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations and contents in Fagus sylvatica, Quercus petraea, and Q. robur at continental and climate region scales using long-term data from the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) and similar datasets. We discussed the results in the light of opposing resource dynamics hypotheses: (i) resource accumulation before mast years and exhaustion after mast years (resource storage hypothesis), (ii) shifting resources from vegetative to generative compartments (resource switching hypothesis), and (iii) investing resources concurrently in both vegetative and generative compartments (resource matching hypothesis). Linear mixed-effects modelling (LMM) showed that both stem growth and leaf production were negatively influenced by weather conditions which simultaneously lead to high fruit production. Thus, the impact of generative on vegetative growth is intermixed with effects of environmental factors. Superposed epoch analyses and LMM showed that for mast behaviour in F. sylvatica, there are indicators supporting the resource storage and the resource switching hypotheses. Before mast years, resources were accumulated, while during mast years resources switched from vegetative to generative tissues with reduced stem and leaf growth. For the Quercus species, stem growth was reduced after mast years, which supports the resource storage hypothesis. LMM showed that leaf C concentrations did not change with increasing fruit production in neither species. Leaf N and P concentrations increased in F. sylvatica, but not in Quercus species. Leaf N and P contents decreased with increasing fruit production in all species, as did leaf C content in F. sylvatica. Overall, our findings suggest different resource dynamics strategies in F. sylvatica and Quercus species, which might lead to differences in their adaptive capacity to a changing climate.
Keywords: climate change, Fagus sylvatica, long-term monitoring, mast fruiting, Quercus petraea, Quercus robur, resource dynamics
Published in DiRROS: 15.07.2021; Views: 885; Downloads: 650
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22. Surprising drought tolerance of Fir (Abies) species between past climatic adaptation and future projections reveals new chances for adaptive forest managementCsaba Mátyás, František Beran, Jaroslav Dostál, Jiří Čáp, Martin Fulín, Monika Vejpustková, Gregor Božič, Pál Balázs, Josef Frýdl, 2021, original scientific article Abstract: esearch Highlights: Data of advanced-age provenance tests were reanalyzed applying a new approach, to directly estimate the growth of populations at their original sites under individually generated future climates. The results revealed the high resilience potential of fir species. Background and Objectives: The growth and survival of silver fir under future climatic scenarios are insufficiently investigated at the xeric limits. The selective signature of past climate determining the current and projected growth was investigated to analyze the prospects of adaptive silviculture and assisted transfer of silver fir populations, and the introduction of non-autochthonous species. Materials and Methods: Hargreaves% climatic moisture deficit was selected to model height responses of adult populations. Climatic transfer distance was used to assess the relative drought stress of populations at the test site, relating these to the past conditions to which the populations had adapted. ClimateEU and ClimateWNA pathway RCP8.5 data served to determine individually past, current, and future moisture deficit conditions. Besides silver fir, other fir species from South Europe and the American Northwest were also tested. Results: Drought tolerance profiles explained the responses of transferred provenances and predicted their future performance and survival. Silver fir displayed significant within-species differentiation regarding drought stress response. Applying the assumed drought tolerance limit of 100 mm relative moisture deficit, most of the tested silver fir populations seem to survive their projected climate at their origin until the end of the century. Survival is likely also for transferred Balkan fir species and for grand fir populations, but not for the Mediterranean species. Conclusions: The projections are less dramatic than provided by usual inventory assessments, considering also the resilience of populations. The method fills the existing gap between experimentally determined adaptive response and the predictions needed for management decisions. It also underscores the unique potential of provenance tests.
Keywords: climate change, common garden, provenance test, silver fir, grand fir, Balkan firs, drought stress, resilience, climate transfer distance, adaptation
Published in DiRROS: 05.07.2021; Views: 930; Downloads: 588
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23. Drought stress can induce the pathogenicity of Cryptostroma corticale, the causal agent of sooty bark disease of sycamore mapleNikica Ogris, Ana Brglez, Barbara Piškur, 2021, original scientific article Abstract: Reports of sooty bark disease of maples caused by the fungus Cryptostroma corticale have recently been emerging from across Europe. The aims of our study were to describe the first report of sooty bark disease in Slovenia, to determine the pathogenicity of C. corticale, to confirm the optimum temperature for the growth of the fungus, and to determine the mass loss of Acer pseudoplatanus wood inoculated by C. corticale. We confirmed the presence of C. corticale on A. pseudoplatanus via morphological and molecular analysis. The optimal growth of C. corticale was measured in vitro on potato dextrose agar and was determined to occur at 25 °C. Pathogenicity tests were performed on 30 saplings of A. pseudoplatanus under two treatments, humid and drought stress, and the fungus was pathogenic in both treatments. The mean length of bark lesions and wood discoloration of the drought-stressed saplings was significantly greater than that in the humid treatment. Re-isolations of C. corticale were successful from all inoculated saplings, and thus Koch%s postulates were confirmed. The mass loss of A. pseudoplatanus wood was determined by mini-block test in a period of 10 weeks and was observed as minimal. Based on the results, we conclude that C. corticale is a weak and opportunistic pathogen that most likely expresses itself intensively under hot and dry conditions.
Keywords: pathogenicity, drought stress, optimal growth, climate change, mass loss, mini-block test, wood rot, opportunistic pathogen, saprophyte, endophyte
Published in DiRROS: 23.03.2021; Views: 1157; Downloads: 874
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24. Continent-wide tree species distribution models may mislead regional management decisions : a case study in the transboundary biosphere reserve Mura-Drava-DanubeMarcus Sallmannshofer, Debojyoti Chakraborty, Harald Vacik, Gábor Illés, Markus Löw, Andreas Rechenmacher, Katharina Lapin, Sophie Ette, Dejan Stojanović, Andrej Kobler, Silvio Schueler, 2021, original scientific article Abstract: The understanding of spatial distribution patterns of native riparian tree species in Europe lacks accurate species distribution models (SDMs), since riparian forest habitats have a limited spatial extent and are strongly related to the associated watercourses, which needs to be represented in the environmental predictors. However, SDMs are urgently needed for adapting forest management to climate change, as well as for conservation and restoration of riparian forest ecosystems. For such an operative use, standard large-scale bioclimatic models alone are too coarse and frequently exclude relevant predictors. In this study, we compare a bioclimatic continent-wide model and a regional model based on climate, soil, and river data for central to south-eastern Europe, targeting seven riparian foundation species%Alnus glutinosa, Fraxinus angustifolia, F. excelsior, Populus nigra, Quercus robur, Ulmus laevis, and U. minor. The results emphasize the high importance of precise occurrence data and environmental predictors. Soil predictors were more important than bioclimatic variables, and river variables were partly of the same importance. In both models, five of the seven species were found to decrease in terms of future occurrence probability within the study area, whereas the results for two species were ambiguous. Nevertheless, both models predicted a dangerous loss of occurrence probability for economically and ecologically important tree species, likely leading to significant effects on forest composition and structure, as well as on provided ecosystem services.
Keywords: bioclimatic model, ecological niche model, forest management, tree species selection, riparian forest habitat, climate change adaptation
Published in DiRROS: 22.03.2021; Views: 1255; Downloads: 850
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25. Global geographic distribution and host range of Fusarium circinatum, the causal agent of pine pitch cankerRein Drenkhan, Beccy Ganley, Jorge Martín García, Petr Vahalík, Kalev Adamson, Katarína Adamčíková, Rodrigo Ahumada, Lior Blank, Helena Bragança, Paolo Capretti, Nikica Ogris, 2020, original scientific article Abstract: Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database (http://bit.do/phytoportal). A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen.
Keywords: invasive pathogen, climate change, interactive map of pathogen, susceptibility
Published in DiRROS: 13.07.2020; Views: 2060; Downloads: 1235
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26. Growth response of different tree species (oaks, beech and pine) from SE Europe to precipitation over timeDejan Stojanović, Tom Levanič, Bratislav Matović, Stefan Stjepanović, Saša Orlović, original scientific article Abstract: Changing climatic conditions can have various consequences for forest ecosystems, from increasing frequencies of forest fires, ice and windstorm events to pathogen outbreaks and mass mortalities. The Standardized Precipitation Index (SPI) was chosen for the evaluation of drought impact on the radial growth of trees after extensive preliminary testing of various calculated monthly climate parameters from the CARPATCLIM database. SPI was calculated for periods between 3 and 36 months for different sites (lowland and mountainous parts of Serbia, Southeast Europe), from which Quercus robur, Q. cerris, Fagus sylvatica and Pinus sylvestris samples were acquired. Bootstrapped Pearson%s correlations between SPI monthly indices and radial growth of tree species were calculated. We found that 12-month SPI for summer months may be a good predictor of positive and negative growth of different species at different sites. The strongest positive correlations for five of six tree-ring width chronologies were between 12-month June and 14-month September SPI, which implies that high growth rates can be expected when the autumn of the previous year, and winter, spring and summer of the current year, are well supplied with precipitation, and vice versa (low precipitation in given period/low growth rates).
Keywords: standardized precipitation index, SPI, climate change, tree mortality, Quercus sp., Fagus sylvatica, Pinus sylvestris
Published in DiRROS: 18.04.2018; Views: 2957; Downloads: 1693
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