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Are heat and cold resistance of Arctic species affected by successive extreme temperature events?

https://arctichealth.org/en/permalink/ahliterature95738
Source
New Phytologist. 2006;170(2):291-300
Publication Type
Article
Date
2006
Author
Marchand, FL
Kockelbergh, F
van de Vijver, B
Beyens, L
Nijs, I
Author Affiliation
Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
Source
New Phytologist. 2006;170(2):291-300
Date
2006
Language
English
Publication Type
Article
Keywords
Arctic Regions
Carex Plant - growth & development - physiology
Chlorophyll - metabolism
Cold Climate
Ericaceae - growth & development - physiology
Fluorescence
Greenhouse Effect
Hot Temperature
Photosynthesis - physiology
Photosystem II Protein Complex - physiology
Plant Leaves - growth & development - physiology
Polygonum - growth & development - physiology
Salix - growth & development - physiology
Species Specificity
Abstract
Extreme temperature events are projected to increase in frequency in a future climate. As successive extremes could occur more frequently, patches of vulnerable tundra vegetation were exposed to two consecutive heat waves (HWs) of 10 d each, with a 5-d recovery period in between. Surface temperatures during the HWs were increased approximately 6 degrees C using infrared irradiation sources. In three of the four target species (Pyrola grandiflora, Polygonum viviparum and Carex bigelowii), plant conditions improved upon the first exposure. Depending on species, leaf relative growth, leaf chlorophyll content or maximal photochemical efficiency was increased. In P. grandiflora the positive effects of the heat on the photosynthetic apparatus led to augmented net photosynthesis. By contrast, Salix arctica responded mainly negatively, indicating species-specific responses. During the second HW, leaf mortality suddenly increased, indicating that the heat stress induced by the extreme events lasted too long and negatively influenced the species resistance to high temperature. After the HWs, when plants were exposed to (low) ambient temperatures again, plant performance deteriorated further, indicating possible loss of cold resistance.
PubMed ID
16608454 View in PubMed
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Biogenic volatile organic compound emissions along a high arctic soil moisture gradient.

https://arctichealth.org/en/permalink/ahliterature290127
Source
Sci Total Environ. 2016 Dec 15; 573:131-138
Publication Type
Journal Article
Date
Dec-15-2016
Author
Sarah Hagel Svendsen
Frida Lindwall
Anders Michelsen
Riikka Rinnan
Author Affiliation
Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK -2100 Copenhagen E, Denmark; Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK -1350 Copenhagen K, Denmark.
Source
Sci Total Environ. 2016 Dec 15; 573:131-138
Date
Dec-15-2016
Language
English
Publication Type
Journal Article
Keywords
Air Pollutants - analysis
Arctic Regions
Climate change
Ecosystem
Environmental Monitoring - methods
Ericaceae - growth & development
Greenland
Rosaceae - growth & development
Salix - growth & development
Soil - chemistry
Volatile Organic Compounds - analysis
Water - analysis
Abstract
Emissions of biogenic volatile organic compounds (BVOCs) from terrestrial ecosystems are important for the atmospheric chemistry and the formation of secondary organic aerosols, and may therefore influence the climate. Global warming is predicted to change patterns in precipitation and plant species compositions, especially in arctic regions where the temperature increase will be most pronounced. These changes are potentially highly important for the BVOC emissions but studies investigating the effects are lacking. The aim of this study was to investigate the quality and quantity of BVOC emissions from a high arctic soil moisture gradient extending from dry tundra to a wet fen. Ecosystem BVOC emissions were sampled five times in the July-August period using a push-pull enclosure technique, and BVOCs trapped in absorbent cartridges were analyzed using gas chromatography-mass spectrometry. Plant species compositions were estimated using the point intercept method. In order to take into account important underlying ecosystem processes, gross ecosystem production, ecosystem respiration and net ecosystem production were measured in connection with chamber-based BVOC measurements. Highest emissions of BVOCs were found from vegetation communities dominated by Salix arctica and Cassiope tetragona, which had emission profiles dominated by isoprene and monoterpenes, respectively. These results show that emissions of BVOCs are highly dependent on the plant cover supported by the varying soil moisture, suggesting that high arctic BVOC emissions may affect the climate differently if soil water content and plant cover change.
PubMed ID
27552736 View in PubMed
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High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert.

https://arctichealth.org/en/permalink/ahliterature294840
Source
Glob Chang Biol. 2017 11; 23(11):5006-5020
Publication Type
Journal Article
Date
11-2017
Author
Stef Weijers
Agata Buchwal
Daan Blok
Jörg Löffler
Bo Elberling
Author Affiliation
Department of Geography, University of Bonn, Bonn, Germany.
Source
Glob Chang Biol. 2017 11; 23(11):5006-5020
Date
11-2017
Language
English
Publication Type
Journal Article
Keywords
Climate change
Ericaceae - growth & development
Greenland
Hot Temperature
Seasons
Abstract
Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growth, but is hindered at many High Arctic sites by short and fragmented instrumental climate records. Moreover, only few High Arctic shrub chronologies cover the recent decade of substantial warming. This study investigated the climatic causes of growth variability of the evergreen dwarf shrub Cassiope tetragona between 1927 and 2012 in the northernmost polar desert at 83°N in North Greenland. We analysed climate-growth relationships over the period with available instrumental data (1950-2012) between a 102-year-long C. tetragona shoot length chronology and instrumental climate records from the three nearest meteorological stations, gridded climate data, and North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. July extreme maximum temperatures (JulTemx ), as measured at Alert, Canada, June NAO, and previous October AO, together explained 41% of the observed variance in annual C. tetragona growth and likely represent in situ summer temperatures. JulTemx explained 27% and was reconstructed back to 1927. The reconstruction showed relatively high growing season temperatures in the early to mid-twentieth century, as well as warming in recent decades. The rapid growth increase in C. tetragona shrubs in response to recent High Arctic summer warming shows that recent and future warming might promote an expansion of this evergreen dwarf shrub, mainly through densification of existing shrub patches, at High Arctic sites with sufficient winter snow cover and ample water supply during summer from melting snow and ice as well as thawing permafrost, contrasting earlier notions of limited shrub growth sensitivity to summer warming in the High Arctic.
PubMed ID
28464494 View in PubMed
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Impact of early and late winter icing events on sub-arctic dwarf shrubs.

https://arctichealth.org/en/permalink/ahliterature273284
Source
Plant Biol (Stuttg). 2014 Jan;16(1):125-32
Publication Type
Article
Date
Jan-2014
Author
C. Preece
G K Phoenix
Source
Plant Biol (Stuttg). 2014 Jan;16(1):125-32
Date
Jan-2014
Language
English
Publication Type
Article
Keywords
Arctic Regions
Chlorophyll - metabolism
Electrolytes - metabolism
Ericaceae - growth & development - metabolism - physiology
Ethanol - metabolism
Fluorescence
Freezing
Seasons
Abstract
Polar regions are predicted to undergo large increases in winter temperature and an increased frequency of freeze-thaw cycles, which can cause ice layers in the snow pack and ice encasement of vegetation. Early or late winter timing of ice encasement could, however, modify the extent of damage caused to plants. To determine impacts of the date of ice encasement, a novel field experiment was established in sub-arctic Sweden, with icing events simulated in January and March 2008 and 2009. In the subsequent summers, reproduction, phenology, growth and mortality, as well as physiological indicators of leaf damage were measured in the three dominant dwarf shrubs: Vaccinium uliginosum, Vaccinium vitis-idaea and Empetrum nigrum. It was hypothesised that January icing would be more damaging compared to March icing due to the longer duration of ice encasement. Following 2 years of icing, E. nigrum berry production was 83% lower in January-iced plots compared to controls, and V. vitis-idaea electrolyte leakage was increased by 69%. Conversely, electrolyte leakage of E. nigrum was 25% lower and leaf emergence of V. vitis-idaea commenced 11 days earlier in March-iced plots compared to control plots in 2009. There was no effect of icing on any of the other parameters measured, indicating that overall these study species have moderate to high tolerance to ice encasement. Even much longer exposure under the January icing treatment does not clearly increase damage.
PubMed ID
23574610 View in PubMed
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Partial mycoheterotrophy in Pyroleae: nitrogen and carbon stable isotope signatures during development from seedling to adult.

https://arctichealth.org/en/permalink/ahliterature267413
Source
Oecologia. 2015 Jan;177(1):203-11
Publication Type
Article
Date
Jan-2015
Author
Veronika A Johansson
Anna Mikusinska
Alf Ekblad
Ove Eriksson
Source
Oecologia. 2015 Jan;177(1):203-11
Date
Jan-2015
Language
English
Publication Type
Article
Keywords
Autotrophic Processes
Carbon - metabolism
Carbon Isotopes - metabolism
Ericaceae - growth & development - metabolism
Fungi - metabolism
Heterotrophic Processes
Mycorrhizae
Nitrogen - metabolism
Nitrogen Isotopes - metabolism
Plant Development
Seedling
Seeds - chemistry
Sweden
Abstract
Mycoheterotrophic plants (MHP) are divided into non-photosynthesizing full MHP and green-leaved partial or initial MHP. We investigated (13)C and (15)N isotope enrichment in five putatively partial MHP species in the tribe Pyroleae (Ericaceae): Chimaphila umbellata, Moneses uniflora, Orthilia secunda, Pyrola chlorantha and Pyrola minor, sampled from forest sites on Öland, Sweden. For M. uniflora and P. chlorantha, we investigated isotope signatures of subterranean seedlings (which are mycoheterotrophic), to examine how the use of seedlings instead of full MHP species (Hypopitys monotropa) as reference species affects the assessment of partial mycoheterotrophy. Our main findings were as follows: (1) All investigated Pyroleae species were enriched in (15)N compared to autotrophic reference plants. (2) significant fungal-derived C among the Pyroleae species was found for O. secunda and P. chlorantha. For the remaining species of C. umbellata, M. uniflora and P. minor, isotope signatures suggested adult autotrophy. (3) C and N gains, calculated using seedlings as a full MHP reference, yielded qualitatively similar results as when using H. monotropa as a reference. However, the estimated differences in C and N gains became larger when using seedlings as an MHP reference. (4) A previously unknown interspecific variation in isotope signature occurs during early ontogeny, from seed production to developing seedlings. Our findings suggest that there is a variation among Pyroleae species concerning partial mycoheterotrophy in adults. Adult autotrophy may be most common in Pyroleae species, and these species may not be as dependent on fungal-derived nutrients as some green orchids.
PubMed ID
25395312 View in PubMed
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