scholarly journals OH reactivity from the emissions of different tree species: investigating the missing reactivity in a boreal forest

2020 ◽  
Vol 17 (18) ◽  
pp. 4681-4705
Author(s):  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Simon Schallhart ◽  
Virpi Tarvainen ◽  
Jaana Bäck ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Large Fraction ◽  
Green Leaf Volatiles ◽  
Mass Spectrometers ◽  
Leaf Volatiles ◽  
Downy Birch ◽  
Very High ◽  
Comparative Reactivity

Abstract. In forested area, a large fraction of total hydroxyl radical (OH) reactivity remains unaccounted for. Very few studies have looked at the variations in total OH reactivity from biogenic emissions. In the present study, we investigate the total OH reactivity from three common boreal tree species (Scots pine, Norway spruce, and downy birch) by comparing it with the calculated reactivity from the chemically identified emissions. Total OH reactivity was measured using the comparative reactivity method (CRM), and the chemical composition of the emissions was quantified with two gas chromatographs coupled with mass spectrometers (GC–MSs). Dynamic branch enclosures were used, and emissions from one branch of a tree at the time were measured by periodically rotating between them. Results show that birch had the highest values of total OH reactivity of the emissions (TOHRE), while pine had the lowest. The main drivers for the known reactivity of pine and spruce were monoterpenes and sesquiterpenes. Birch emissions were dominated by sesquiterpenes, but monoterpenes and green leaf volatiles (GLVs) were present as well. However, calculated reactivity values remained low, leading to the highest missing fraction of reactivity (>96 %), while pine and spruce had similar missing reactivity fractions between 56 % and 82 % (higher in the spring and decreasing as the summer proceeded). The high average values were driven by low-reactivity periods, and the fraction of missing reactivity got smaller for pine and spruce when the TOHRE values increased. Important exceptions were identified for periods when the emission profiles changed from terpenes to GLVs, a family of compounds containing a backbone of six carbon atoms with various functionalities (e.g. alcohols, aldehydes, esters) that indicate that the plant is suffering from stress. Then, very high TOHRE values were measured, and the missing fraction remained high. This study found a different trend in the missing OHRE fraction of the Norway spruce from spring to autumn compared to one previous study (Nölscher et al., 2013), which indicates that additional studies are required to fully understand the complexity of biogenic reactive emissions. Future studies of boreal trees in situ should be conducted to confirm the findings presented.

scholarly journals OH reactivity from different tree species: Investigating the missing reactivity in a boreal forest

2020 ◽  
Author(s):  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Simon Schallhart ◽  
Virpi Tarvainen ◽  
Jaana Bäck ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Large Fraction ◽  
Green Leaf Volatiles ◽  
Mass Spectrometers ◽  
Leaf Volatiles ◽  
Downy Birch ◽  
Very High ◽  
Comparative Reactivity

Abstract. In forested area, a large fraction of total hydroxyl radical (OH) reactivity remain unaccounted for. Very few studies have been looking at total OH reactivity from biogenic emissions and its variations. In the present study, we investigate the total OH reactivity from three common boreal tree species (Scots pine, Norway spruce, and Downy birch), by comparing it with the calculated reactivity from the chemically identified emissions. Total OH reactivity was measured using the Comparative Reactivity Method (CRM), and the chemical composition of the emissions was quantified with two gas chromatographs coupled to mass spectrometers (GC-MSs). Dynamic branch enclosures were used and emissions from one branch of a tree at the time were measured by rotating between them periodically. Results show that birch had the highest values of total OH reactivity of the emissions (TOHRE), while pine had the lowest. The main drivers for the known reactivity of pine and spruce were monoterpenes and sesquiterpenes. For birch, emissions were dominated by sesquiterpenes, even though monoterpenes and GLVs could be found too. However, calculated reactivity values remained low leading to the highest missing fraction of reactivity (>96 %), while pine and spruce had similar missing reactivity fractions between 56 % and 82 % (higher in the spring and decreasing as the summer proceeded). The high average values were driven by low reactivity periods and the fraction of missing reactivity got smaller for pine and spruce when the TOHRE values increased. Important exceptions were identified for periods when the emission profiles changed from terpenes to Green Leaf Volatiles (GLVs), a family of compounds containing a 6 carbon atoms backbone with various functionalities (e.g. alcohols, aldehydes, esters) that indicate that the plant is suffering from stress. Then, very high TOHRE values were measured and the missing fraction remained high. This study found a different trend in the missing OHRE fraction of Norway spruce from spring to autumn compared to one previous study (Nölscher et al., 2013), which indicates that additional studies are required to fully understand the complexity of biogenic reactive emissions. Future studies of boreal trees in situ should be conducted to confirm the findings presented.

scholarly journals Sesquiterpenes and oxygenated sesquiterpenes dominate the emissions of downy birches

2020 ◽  
Author(s):  
Heidi Hellén ◽  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Aku Helin ◽  
Simon Schallhart ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Growing Season ◽  
Green Leaf Volatiles ◽  
Forest Site ◽  
Bud Break ◽  
Mass Spectrometers ◽  
Leaf Volatiles ◽  
Strong Source ◽  
Downy Birch

Abstract. Even though isoprene and monoterpene (MT) emissions of boreal needle trees have been studied quite intensively, there is less knowledge on the emissions of broadleaved deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds (OVOCs). Here we studied the downy birch (Betula pubescens) leaf emissions of terpenes, OVOCs and green leaf volatiles (GLVs) at the SMEAR II boreal forest site using in situ gas chromatographs with mass spectrometers in 2017 and 2019. The highest emissions were detected during the early growing season, indicating that bud break and early leaf growth are a strong source of these compounds. Sesquiterpenes (SQTs) and oxygenated sesquiterpenes (OSQTs) were the main emitted compounds almost throughout the summer. Mean emissions (averaged over bud break/early/main and late growing season) of SQTs and OSQTs were 5–690 and 46–650 ng gdw−1 h−1, respectively. Isoprene emissions were very low or below detection limits (seasonal means

scholarly journals INTEGRATED EFFECT OF CLIMATE AND AIR POLLUTANTS ON DIURNAL TREE RING FORMATION OF SCOTS PINE, NORWAY SPRUCE AND SILVER AND DOWNY BIRCH TREES STEM CIRCUMFERENCE

2018 ◽  
Author(s):  
Ainis PIVORAS ◽  
Marius MIKALAJŪNAS ◽  
Diana JUONYTĖ ◽  
Gintaras PIVORAS
Keyword(s):  
Norway Spruce ◽  
Tree Ring ◽  
Tree Species ◽  
Surface Ozone ◽  
Stress Factors ◽  
Global Changes ◽  
Growth Intensity ◽  
Recent Climate ◽  
Birch Trees ◽  
Downy Birch

The integrated effect of climatic and other abiotic stress factors including surface ozone on diurnal tree ring width formation of the prevailing in Lithuania tree species as the main response parameter of tree capacity to adapt to and mitigate the recent global changes was investigated. The obtained data revealed that Norway spruce is better adapted to recent climatic conditions in temperate forest than birch trees. Even during the drought episode spruce stem increment exceeded increment of the rest of considered tree species. Silver and Downy birch tree reactions revealed the lowest sensitivity of these tree species not only to unfavorable environmental factors but also to favorable factors which should stimulate tree growth intensity. This is why the growth intensity of this tree species recently has been gradually decreasing. The hypothesis that the coniferous species are more adaptive to recent climate changes was confirmed. The study is based on the results obtained conducting national project supported by Lithuanian Council of Research “FOREstRESS” (SIT- 3/2015).

The complexity of biogenic boreal emissions through the lens of hydroxyl radical (OH) reactivity

2020 ◽  
Author(s):  
Arnaud P. Praplan ◽  
Simon Schallhart ◽  
Toni Tykkä ◽  
Jaana Bäck ◽  
Heidi Hellén
Keyword(s):  
Boreal Forest ◽  
Hydroxyl Radical ◽  
Norway Spruce ◽  
Large Fraction ◽  
High Stress ◽  
Chem Phys ◽  
Stress Factors ◽  
Unknown Primary ◽  
In Situ Conditions ◽  
Downy Birch

<p><span>Di Carlo et al. (2004) identified a discrepancy between measured total hydroxyl radical (OH) reactivity and the OH reactivity derived from the known air chemical composition in a forested environment. This </span><span><em>missing</em></span><span> reactivity has also been observed in the boreal forest (Sinha et al., 2010; Nölscher et al., 2012; Praplan et al., 2019). It remains ambiguous (e.g. Nölscher et al., 2013) if this missing reactivity stems from unknown primary emissions of volatile organic compounds (VOCs) from vegetation or from other sources (e.g. soil).</span></p><p><span>In order to further investigate emissions from a boreal forest, we applied the Comparative Reactivity Method (CRM; Sinha et al., 2008; Praplan et al., 2017) to emission measurements. Simultaneously, the emissions were chemically characterized with on-line gas chromatography coupled to mass spectrometery (GC/MS) methods.</span></p><p><span>In a first stage of the study (May to October 2017), measurements alternated between seedlings of Scots pine (</span><span><em>Pinus sylvestris</em></span><span>), Norway spruce (</span><span><em>Picea abies</em></span><span>), and downy birch (</span><span><em>Betula pubescens</em></span><span>). They were placed in pots outside of the container were the instrumentation was placed at the SMEAR II station in Hyytiälä, Finland. In a second stage (May to September 2019), emissions from forest trees (Norway spruce and Downy birch) for in situ conditions were analysed.</span></p><p><span>The results show large variations of emission profiles and amounts throughout the year. In particular seedling were subject to periods of high stress which saw a large fraction of Green Leaf Volatiles (GLVs) contributing to the reactivity and a general increase of the emissions and the total observed reactivity. Trees from the forest were less prone to such stress and their emissions are higher in the spring and early summer compared to later summer and autumn.</span></p><p><span>While the presented dataset is limited and difficult to extrapolate from, it highlights important factors that need to be taken into account when modelling emissions: variability between tree species and individual trees, seasonal variations (slow changes) and stress factors (rapid changes), for instance.</span></p><p><strong>References:</strong></p><ul><li><span>Di Carlo et al. (2004), </span><span><em>Science</em></span><span>, 304, 722–725, doi:10.1126/science.1094392.<br></span></li> <li><span>Nölscher et al. (2012), </span><span><em>Atmos. </em></span><em>Chem. Phys.</em>, 12, 8257–8270, doi:10.5194/acp-12-8257-2012.</li> <li>Nölscher et al. (2013), <em>Biogeosciences</em>, 10, 4241–4257, doi:10.5194/bg-10-4241-2013.</li> <li>Praplan et al. (2017), <em>Atmos. Env.</em>, 169, 150–161, doi:10.1016/j.atmosenv.2017.09.013.</li> <li>Praplan et al. (2019), <em>Atmos. Chem. Phys.</em>, 19, 14431–14453, doi:10.5194/acp-19-14431-2019.</li> <li>Sinha et al. (2008), <em>Atmos. Chem. Phys.</em>, 8, 2213–2227, doi:10.5194/acp-8-2213-2008.</li> <li>Sinha et al. (2010), <em>Environ. Sci. Technol.</em>, 44, 6614–6620, doi:10.1021/es101780b.</li> </ul>

scholarly journals Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

2012 ◽  
Vol 9 (12) ◽  
pp. 5111-5123 ◽  
Author(s):  
E. Kleist ◽  
T. F. Mentel ◽  
S. Andres ◽  
A. Bohne ◽  
A. Folkers ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
High Temperatures ◽  
Tree Species ◽  
De Novo ◽  
Heat Waves ◽  
Green Leaf Volatiles ◽  
Leaf Volatiles ◽  
Resin Ducts ◽  
As Stress

Abstract. Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress) on plants changing emissions of biogenic volatile organic compounds (BVOCs). As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress. In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease. Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do not consider stress impacts.

scholarly journals Morphological Variation in Absorptive Roots in Downy Birch (Betula pubescens) and Norway Spruce (Picea abies) Forests Growing on Drained Peat Soils

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 112
Author(s):  
Azadeh Rezapour ◽  
Marika Truu ◽  
Martin Maddison ◽  
Gristin Rohula-Okunev ◽  
Arvo Tullus ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Morphological Variation ◽  
Tree Species ◽  
Morphological Traits ◽  
Morphological Changes ◽  
Management Practice ◽  
Specific Response ◽  
Downy Birch ◽  
Absorptive Roots ◽  
The Mean

Peatland drainage based on ditch systems is a widely used forestry management practice in the boreal and hemiboreal forests to improve tree growth. This study investigated the morphological variation in absorptive roots (first- and second-order roots) across the distance gradient from the ditch with four sampling plots (5, 15, 40, and 80 m) in six drained peatland forests dominated by Downy birch and Norway spruce. The dominating tree species had a significant effect on the variation in absorptive root morphological traits. The absorptive roots of birch were thinner with a higher specific root area and length (SRA and SRL), higher branching intensity (BI), and lower root tissue density (RTD) than spruce. The distance from the ditch affected the absorptive root morphological traits (especially SRA and RTD), but this effect was not dependent on tree species and was directionally consistent between birch and spruce. With increased distance from the ditch (from plot 5 to plot 80), the mean SRA increased by about 10% in birch and 5% in spruce; by contrast, the mean RTD decreased by about 10% in both tree species, indicating a potential shift in nutrient foraging. However, soil physical and chemical properties were not dependent on the distance from the ditch. We found a species-specific response in absorptive root morphological traits to soil properties such as peat depth, pH, and temperature. Our results should be considered when evaluating the importance of morphological changes in absorptive roots when trees acclimate to a changing climate.

scholarly journals Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C<sub>5</sub>–C<sub>20</sub>) emissions of downy birches

2021 ◽  
Vol 21 (10) ◽  
pp. 8045-8066
Author(s):  
Heidi Hellén ◽  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Aku Helin ◽  
Simon Schallhart ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Leaf Growth ◽  
Growing Season ◽  
Green Leaf Volatiles ◽  
Forest Site ◽  
Leaf Volatiles ◽  
Volatile Organic ◽  
Downy Birch

Abstract. Biogenic volatile organic compounds (BVOCs) emitted by the forests are known to have strong impacts in the atmosphere. However, lots of missing reactivity is found, especially in the forest air. Therefore better characterization of sources and identification/quantification of unknown reactive compounds is needed. While isoprene and monoterpene (MT) emissions of boreal needle trees have been studied quite intensively, there is much less knowledge on the emissions of boreal deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds (OVOCs). Here we quantified the downy birch (Betula pubescens) leaf emissions of terpenes, oxygenated terpenes and green leaf volatiles (GLVs) at the SMEAR II boreal forest site using in situ gas chromatographs with mass spectrometers. Sesquiterpenes (SQTs) and oxygenated sesquiterpenes (OSQTs) were the main emitted compounds. Mean emission rates of SQTs and OSQTs were significantly higher in the early growing season (510 and 650 ng gdw-1 h−1, respectively) compared to in the main (40 and 130 ng gdw-1 h−1, respectively) and late (14 and 46 ng gdw-1 h−1, respectively) periods, indicating that early leaf growth is a strong source of these compounds. The emissions had a very clear diurnal variation with afternoon maxima being on average 4 to 8 times higher than seasonal means for SQTs and OSQTs, respectively. β-Caryophyllene and β-farnesene were the main SQTs emitted. The main emitted OSQTs were tentatively identified as 14-hydroxy-β-caryophyllene acetate (M=262 g mol−1) and 6-hydroxy-β-caryophyllene (M=220 g mol−1). Over the whole growing season, the total MT emissions were only 24 % and 17 % of the total SQT and OSQT emissions, respectively. A stressed tree growing in a pot was also studied, and high emissions of α-farnesene and an unidentified SQT were detected together with high emissions of GLVs. Due to the relatively low volatility and the high reactivity of SQTs and OSQTs, downy birch emissions are expected to have strong impacts on atmospheric chemistry, especially on secondary organic aerosol (SOA) production.

scholarly journals Annual net nitrogen mineralization and litter flux in well-drained downy birch, Norway spruce and Scots pine forest ecosystems

Silva Fennica ◽  
2018 ◽  
Vol 52 (4) ◽  
Author(s):  
Hardo Becker ◽  
Jürgen Aosaar ◽  
Mats Varik ◽  
Gunnar Morozov ◽  
Kristiina Aun ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Nitrogen Mineralization ◽  
Tree Species ◽  
Low Fertility ◽  
Net Nitrogen Mineralization ◽  
N Input ◽  
Downy Birch ◽  
The Difference ◽  
Study Sites

The main aim of the current study was to estimate the annual net nitrogen mineralization (NNM) flux in stands of different tree species growing on drained peatlands, as well as to clarify the effect of tree species, soil properties and litter on annual NNM dynamics. Three study sites were set up in May 2014: a downy birch ( Ehrh.) stand and a Norway spruce ( (L.) Karst.) stand in full-drained swamp (ODS) and a Scots pine ( L.) stand in full-drained swamp (MDS). The NNM flux was estimated using the method with incubated polyethylene bags. The highest value of NNM was found in stands that were growing on fertile ODS: 127.5 kg N ha yr and 87.7 kg N ha yr, in the downy birch stand and in the Norway spruce stand, respectively. A significantly lower annual NNM flux (11.8 kg N ha yr) occurred in the Scots pine stand growing in MDS. Nitrification was highest at fertile ODS sites and ammonification was the highest at the low fertility MDS site. For all study sites, positive correlation was found between soil temperature and NNM intensity. The difference in annual NNM between the downy birch stand and the Norway spruce stand growing on similar drained fertile peatlands was due to litter quality. The annual N input into the soil through leaf litter was the highest at the downy birch site where also the C/N ratio of litter was the lowest. The second highest N input into the soil was found in the spruce stand and the lowest in the pine stand.Betula pubescensPicea abiesOxalisPinus sylvestrisMyrtillusin situ–1–1–1–1–1–1

Distribution and diversity of tree species with respect to soil electrical characteristics in Finnish Lapland

2002 ◽  
Vol 32 (7) ◽  
pp. 1158-1170 ◽  
Author(s):  
R Sutinen ◽  
A Teirilä ◽  
M Pänttäjä ◽  
M -L Sutinen
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Tree Species ◽  
Solute Concentration ◽  
Soil Parameters ◽  
Timber Species ◽  
Electrical Characteristics ◽  
Mature Trees ◽  
Finnish Lapland ◽  
Downy Birch

Soil dielectric permittivity (ε), which is dependent on soil water content (θv), and electrical conductivity (σ), which is dependent on soil solute concentration, were measured in the immediate vicinity of 7596 mature trees naturally established on glacial deposits across granitoid and greenstone assemblages in Finnish Lapland (67°30' N-68°40' N). The proportions of the main timber species Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), and downy birch (Betula pubescens Ehrh.) or the diversity of tree species were not affected by the temperature sum (between 750 and 600 degree-days), but the occurrences were strongly influenced by the soil's electrical characteristics. Scots pine and silver birch (Betula pendula Roth) were found to only occupy dry soils (fixed effect estimates ε(p) = 8.5 and ε(sb) = 8.3) with low solute concentration (σ(p) = 0.64 mS·m-1 and σ(sb) = 0.56 mS·m-1), while Norway spruce, downy birch, aspen (Populus tremula L.) and sallow (Salix caprea L.) occupied sites with higher soil moisture (ε(s) = 17.0, ε(db) = 14.7, ε(a) = 16.7, and ε(sa) = 16.7) and solute concentration (σ(s) = 0.96 mS·m-1, σ(db) = 0.90 mS·m-1, σ(a) = 1.07 mS·m-1, and σ(sa) = 0.93 mS·m-1). Species diversity was found to be at its highest with the following soil parameters: 12 < ε < 15 and 0.8 < σ < 1.2 mS·m-1. Scots pine was concentrated on tills derived from granitoid rocks. Norway spruce dominated sites on tills particularly derived from the mafic metavolcanic rocks of the Greenstone Belt but did not occur on tills derived from granulite. The edaphic constraint for pine appeared to be θv > 0.27 cm3·cm-3 (ε > 15) and for spruce σ < 0.5 mS·m-1, respectively.

scholarly journals Impact of heat stress on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

2012 ◽  
Vol 9 (7) ◽  
pp. 9533-9570
Author(s):  
E. Kleist ◽  
T. F. Mentel ◽  
S. Andres ◽  
A. Bohne ◽  
A. Folkers ◽  
...  
Keyword(s):  
Heat Stress ◽  
Tree Species ◽  
De Novo ◽  
Heat Waves ◽  
European Beech ◽  
Green Leaf Volatiles ◽  
Green Leaf ◽  
Leaf Volatiles ◽  
Resin Ducts ◽  
Laboratory Setup

Abstract. Changes in the biogenic volatile organic compound (BVOC) emissions from European beech, Palestine oak, Scots pine, and Norway spruce exposed to heat stress were measured in a laboratory setup. In general, heat stress decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. Decreasing emission strength with heat stress was independent of the tree species and whether the de novo emissions being constitutive or induced by biotic stress. In contrast, heat stress induced emissions of green leaf volatiles. It also amplified the release of monoterpenes stored in resin ducts of conifers probably due to heat-induced damage of these resin ducts. The increased release of monoterpenes could be strong and long lasting. But, despite of such strong monoterpene emission pulses, the net effect of heat stress on BVOC emissions from conifers can be an overall decrease. In particular during insect attack on conifers the plants showed de novo emissions of sesquiterpenes and phenolic BVOC which exceeded constitutive monoterpene emissions from pools. The heat stress induced decrease of these de novo emissions was larger than the increased release caused by damage of resin ducts. We project that global change induced heat waves may cause increased BVOC emissions only in cases where the respective areas are predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOC. Otherwise the overall effect of heat stress will be a decrease in BVOC emissions.

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