| 1. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- De Frenne, Pieter, et al.
(författare)
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Plant movements and climate warming : intraspecific variation in growth responses to nonlocal soils
- 2014
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 202:2, s. 431-441
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Tidskriftsartikel (refereegranskat)abstract
- Most range shift predictions focus on the dispersal phase of the colonization process. Because moving populations experience increasingly dissimilar nonclimatic environmental conditions as they track climate warming, it is also critical to test how individuals originating from contrasting thermal environments can establish in nonlocal sites. We assess the intraspecific variation in growth responses to nonlocal soils by planting a widespread grass of deciduous forests (Milium effusum) into an experimental common garden using combinations of seeds and soil sampled in 22 sites across its distributional range, and reflecting movement scenarios of up to 1600km. Furthermore, to determine temperature and forest-structural effects, the plants and soils were experimentally warmed and shaded. We found significantly positive effects of the difference between the temperature of the sites of seed and soil collection on growth and seedling emergence rates. Migrant plants might thus encounter increasingly favourable soil conditions while tracking the isotherms towards currently colder' soils. These effects persisted under experimental warming. Rising temperatures and light availability generally enhanced plant performance. Our results suggest that abiotic and biotic soil characteristics can shape climate change-driven plant movements by affecting growth of nonlocal migrants, a mechanism which should be integrated into predictions of future range shifts.
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| 3. |
- Broska, Igor, et al.
(författare)
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Alpine stacking of two Variscan granite blocks recognised from mineral stabilities, age and structural data (Western Carpathians)
- 2024
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Ingår i: Chemical Geology. - : Elsevier. - 0009-2541 .- 1872-6836. ; 648
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Tidskriftsartikel (refereegranskat)abstract
- This study presents petrological, geochemical, geochronological and structural data that serve to identify two different Alpine tectonic units formed from the Variscan-aged Tribeč-Zobor granitic rocks. The proposed model for juxtaposition of two granite blocks in the Tribeč-Zobor basement during the Alpine orogeny is based on the degree of granite alteration, particularly related to differences in monazite stabilities of the S-type granitic rocks along the studied NW- SE profile through the Tribeč-Zobor mountain range. Along the cross-section, the Variscan crystalline basement in the mountain crest is composed of hydrothermally altered and metamorphosed S-type monzogranite (zircon age: 355.2 ± 1.2 Ma). Below this monzogranite there are hypidiomorphic non-altered granitic rocks with ages spanning from 357.8 ± 0.66 Ma to 351.2 ± 0.7 Ma for northeast S-type and 358.2 ± 0.85 Ma to 347.9 ± 0.94 Ma for I-type on southwest part of profile. U-Th-Pb dating revealed both low- and high-Y types of monazite in the S-type granites. Low-Y monazite from both the structurally lower unaltered, and the structurally upper, metamorphosed S-type granitic rocks provides Tournaisian Variscan ages in the range of 354–349 Ma. The high-Y monazite from the same rocks records Visean ages in the range of 348–335 Ma, likely indicating later-staged thermal rock overprinting. Monazites from non-altered S-type granodiorites are stable due to rapid emplacement in the upper crustal position. In contrast, the monazites in the overlying metamorphosed S-type granites are retrogressed to allanite as a result of slower, nearly isobaric cooling of the granites emplaced at deeper crustal levels. Thus, monazite behaviour indicate two different Variscan granite blocks, similar in age but with different emplacement depths. The conditions for metamorphism (450–500 °C, 750–800 MPa) of the structurally upper granites are inferred from phase equilibrium thermodynamic modelling, occurring during the Alpine orogeny. These metamorphic conditions are similar to those calculated for granites of the Western Carpathians that were pervasively reworked during Alpine orogenesis, indicating that structurally upper granites have an affinity to the Alpine Fatric Unit, whereas the lower granite is rather related to the Tatric Unit. An Alpine date of c. 78 Ma yielded by single grain fusion 40Ar/39Ar geochronology of muscovite is interpreted to post-date Alpine thrusting. The present position of the metamorphosed Variscan Fatric granitic rock in the Tribeč-Zobor crystalline basement, overlying both S- and I- non-altered Tatric granites, resulted from large-scale, north-directed Alpine thrusting. The geometry of the thrust, elucidated by tectonic elements from mylonites and hydrothermally altered Triassic quartzites deposited on Fatric granites, is inclined 20–40° to the northwest.
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| 4. |
- De Frenne, Pieter, et al.
(författare)
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Microclimate moderates plant responses to macroclimate warming
- 2013
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 110:46, s. 18561-18565
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Tidskriftsartikel (refereegranskat)abstract
- Recent global warming is acting across marine, freshwater, and terrestrial ecosystems to favor species adapted to warmer conditions and/or reduce the abundance of cold-adapted organisms (i.e., thermophilization of communities). Lack of community responses to increased temperature, however, has also been reported for several taxa and regions, suggesting that climatic lags may be frequent. Here we show that microclimatic effects brought about by forest canopy closure can buffer biotic responses to macroclimate warming, thus explaining an apparent climatic lag. Using data from 1,409 vegetation plots in European and North American temperate forests, each surveyed at least twice over an interval of 12-67 y, we document significant thermophilization of ground-layer plant communities. These changes reflect concurrent declines in species adapted to cooler conditions and increases in species adapted to warmer conditions. However, thermophilization, particularly the increase of warm-adapted species, is attenuated in forests whose canopies have become denser, probably reflecting cooler growing-season ground temperatures via increased shading. As standing stocks of trees have increased in many temperate forests in recent decades, local microclimatic effects may commonly be moderating the impacts of macroclimate warming on forest understories. Conversely, increases in harvesting woody biomass-e.g., for bioenergy-may open forest canopies and accelerate thermophilization of temperate forest biodiversity.
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| 5. |
- De Schuyter, Wim, et al.
(författare)
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Declining potential nectar production of the herb layer in temperate forests under global change
- 2024
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Ingår i: Journal of Ecology. - 0022-0477 .- 1365-2745. ; 112:4, s. 832-847
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Tidskriftsartikel (refereegranskat)abstract
- Wild pollinators are crucial for ecosystem functioning and human food production and often rely on floral resources provided by different (semi-) natural ecosystems for survival. Yet, the role of European forests, and especially the European forest herb layer, as a potential provider of floral resources for pollinators has scarcely been quantified.In this study, we measured the potential nectar production (PNP) of the forest herb layer using resurvey data across 3326 plots in temperate forests in Europe, with an average time interval of 41 years between both surveys in order to assess (i) the importance of the forest herb layer in providing nectar for wild pollinators, (ii) the intra-annual variation of PNP, (iii) the overall change in PNP between survey periods and (iv) the change in intra-annual variation of PNP between survey periods. The PNP estimates nectar availability based on the relative cover of different plant species in the forest herb layer. Although PNP overestimates actual nectar production, relative differences amongst plots provide a valid and informative way to analyse differences across time and space.Our results show that the forest herb layer has a large potential for providing nectar for wild pollinator communities, which is greatest in spring, with an average PNP of almost 16 g sugar/m2/year. However, this potential has drastically declined (mean plot-level decline >24%).Change in light availability, associated with shifts in canopy structure and canopy composition, is the key driver of temporal PNP changes.Synthesis. Our study shows that if management activities are carefully planned to sustain nectar-producing plant species for wild pollinators, European forest herb layers and European forests as a whole can play key roles in sustaining wild pollinator populations.
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| 6. |
- Hovander, Lotta, et al.
(författare)
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Levels of PCBs and their metabolites in the serum of residents of a highly contaminated area in eastern Slovakia
- 2006
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 40:12, s. 3696-3703
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Tidskriftsartikel (refereegranskat)abstract
- The over-riding aim of the present investigation was to obtain information concerning exposure that can be used as a basis for studies on the health of individuals residing in the Michalovce area of eastern Slovakia which is heavily contaminated by polychlorinated biphenyls (PCBs). Accordingly, this work focused on determination of serum concentrations of hydroxylated (OH-PCBs) and methylsulfonyl-substituted (MeSO2-PCBs) metabolites of PCBs. One hundred and twenty-two men and women, 20-59 years of age, living in the contaminated area and 175 from the control Stropkov/Svidnik district were selected randomly from 2047 sampled individuals. Following a specially designed cleanup, the levels of various congeners of OH-PCBs and MeSO2-PCBs in their serum were quantitated by gas chromatography and mass spectrometry, with comparison to authentic reference standards. The median concentrations of PCB congeners and their OH-PCB and MeSO2-PCB metabolites were 2-3-fold higher in residents of Michalovce than in the control region. The levels of certain OH-PCB metabolites were in the same high range as those of individual PCB congeners, whereas the MeSO2-PCB levels were significantly lower. The PCB and their metabolites were present at slightly higher concentrations in men than in women, and the serum levels of PCBs and MeSO2-PCBs increased with increasing age. Thus, the environmental contamination resulting from previous industrial production of PCBs has led to elevated concentrations of PCBs and their metabolites in the serum of individuals living in the Michalovce area.
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| 7. |
- Langer, Pavel, et al.
(författare)
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Possible effects of persistent organochlorinated pollutants cocktail on thyroid hormone levels and pituitary-thyroid interrelations.
- 2007
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Ingår i: Chemosphere. - 0045-6535. ; 70:1, s. 110-118
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Tidskriftsartikel (refereegranskat)abstract
- In polluted district of Michalovce in East Slovakia (POLL) and two districts with background pollution (BCGR) 2046 adults (834 males and 1212 females aged 20-75 years) were examined. Serum levels of thyrotropin (TSH), free thyroxine (FT4), total triiodothyronine (TT3) and antithyroperoxidase antibodies (TPOab) were estimated by electrochemiluminiscent assay and also these of 15 polychlorinated biphenyl congeners (PCBs), p,p'-DDE, p,p'-DDT, hexachlorobenzene (HCB) and hexachlorocyclohexane were measured by high resolution gas chromatography/mass spectrometry. In addition, also dioxins, furans, coplanar- and mono-ortho-PCBs as well as selected hydroxylated and methylsulphonated PCBs and DDE metabolites were measured by appropriate methods based on gas chromatography/mass spectrometry principle. In POLL significantly higher levels of all organochlorines were found than these in BCGR. When pooled values from both areas were stratified in terms of PCBs level and treated as continuous variables, positive association of PCBs with FT4 and TT3 was found, the latter two being also mutually associated. However, within the category of PCBs level <530ng/glipid (n=232) the association between PCBs and both the FT4 (p<0.09) and TT3 (p<0.03) was negative and any association of these was not found within the category of PCBs level of 531-1000ng/g (n=691). In contrast, in the category of 531-2000ng/g (n=1307) positive association appeared between PCBs and FT4 (p<0.001) as well as TT3 (p<0.05). Highly significant association of PCBs with FT4 (p<0.001) was further found in the categories with PCBs level of 1001-101414ng/g (n=1307) and 2001-101414 (n=1123), while significant association with TT3 was observed only in the category of 531-2000ng/g. Such findings suggest possible threshold level in positive effect of PCBs on FT4 and TT3 level which seems to be individual and located somewhere around the PCBs level of 1000ng/g. However, highly significant negative association of both FT4 and TT3 with TSH was found in each of above indicated PCBs categories. Considerable difference in FT4 and TT3 level between large groups of subjects with the same range of PCBs level was also found suggesting different individual susceptibility to the effects of organochlorines. Among a total of 26 cases from POLL with very low TSH level (<0.5mUl(-1)) 13 cases showed very high level of PCBs, FT4 and TT3, thus supporting a hypothesis on a novel sporadic form of high PCBs related peripheral subclinical hyperthyroidism possibly resulting from the long-term disruption of equilibrium between bound and free thyroxine in plasma by high PCBs level followed by a striking inhibition of TSH release from the pituitary.
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| 8. |
- Langer, Pavel, et al.
(författare)
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Thyroid ultrasound volume, structure and function after long-term high exposure of large population to polychlorinated biphenyls, pesticides and dioxin.
- 2007
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Ingår i: Chemosphere. - 0045-6535. ; 69:1, s. 118-27
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Tidskriftsartikel (refereegranskat)abstract
- We examined 2,046 adults (834 males and 1,212 females aged 20-75 years) from polluted district in East Slovakia (POLL) and two neighboring upstream and upwind located districts of background pollution (BCGR). By ultrasound we estimated the thyroid volume (ThV), hypoechogenicity (HYE), nodules and cysts. Serum levels of thyrotropin (TSH), thyroperoxidase antibodies (TPOab) and thyroglobulin were estimated by electrochemiluminiscent assay and these of 15 PCB congeners, p,p'-DDE, p,p'-DDT, hexachlorobenzene (HCB) and hexachlorocyclohexane by high-resolution gas chromatography. In 320 subjects also selected hydroxylated and methylsulfonated PCB metabolites, polychlorinated dibenzo-dioxins (PCDDs), -furans (PCDFs), five dioxin-like coplanar and eight mono-ortho PCB congeners were estimated. Urinary iodine was measured by automatic microplate method. Reciprocal positive association was found between three major POPs (PCBs, DDE and HCB), the levels of these and also PCDDs plus PCDFs in polluted area being considerably higher than in background pollution area. ThV in groups of males and females from POLL with high PCBs level was significantly higher (p<0.001 by t-test) then in age and sex matched groups from BCGR with low PCBs level. In 1,048 males and females aged <60 years with serum PCBs level >1,000 ng g(-1) lipid (median=1,756 ng g(-1)) a significant effect of age on ThV was found (p<0.01 by ANOVA), while in 921 respective subjects with PCBs level <1,000 ng g(-1) (median=661 ng g(-1)) it was not. These findings supported the view on the additional effect of PCBs on ThV other than that of age. Since the urinary iodine in both districts showed optimal range, any interfering effect of unsatisfactory iodine intake on ThV may be excluded. The frequency of autoimmune thyroiditis signs such as HYE, increased serum level of TPOab and TSH resulting in subclinical or overt thyroid hypofunction was positively associated with sex, age and organochlorine levels. The increase of such frequency in males with POPs levels was much more abrupt than that in females. No considerable differences in the frequency of thyroid nodules as related to PCBs level were found.
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