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Effect of repeated freeze-thaw cycles on geographically different populations of the freeze-tolerant worm Enchytraeus albidus (Oligochaeta).

https://arctichealth.org/en/permalink/ahliterature264272
Source
J Exp Biol. 2014 Nov 1;217(Pt 21):3843-52
Publication Type
Article
Date
Nov-1-2014
Author
Karina Vincents Fisker
Martin Holmstrup
Hans Malte
Johannes Overgaard
Source
J Exp Biol. 2014 Nov 1;217(Pt 21):3843-52
Date
Nov-1-2014
Language
English
Publication Type
Article
Keywords
Acclimatization - physiology
Analysis of Variance
Animals
Carbohydrates - analysis
Energy Metabolism - physiology
Freezing
Geography
Germany
Iceland
Models, Biological
Oligochaeta - physiology
Svalbard
Abstract
Freeze-tolerant organisms survive internal ice formation; however, the adaptations to repeated freeze-thaw cycles are often not well investigated. Here we report how three geographically different populations of Enchytraeus albidus (Germany, Iceland and Svalbard) respond to three temperature treatments - constant thawed (0°C), constant freezing (-5°C) and fluctuating temperature (0 to -5°C) - over a period of 42 days. Survival varied between treatments and populations such that enchytraeids from arctic locations had a higher survival following prolonged freeze periods compared with temperate populations. However, enchytraeids from temperate locations had the same survival rate as arctic populations when exposed to repeated freeze-thaw events. Across all populations, metabolic rate decreased markedly in frozen animals (-5°C) compared with thawed controls (0°C). This decrease is likely due to the lower temperature of frozen animals, but also to the transition to the frozen state per se. Animals exposed to repeated freeze-thaw events had an intermediate metabolic rate and freeze-thaw events were not associated with pronounced excess energetic costs. Overwintering under either condition was not associated with a decrease in lipid content; however, during exposure to constant freezing and repeated freeze-thaw events there was a noticeable decrease in carbohydrate stores over time. Thus, animals exposed to constant freezing showed a decrease in glycogen stores, while both glucose and glycogen content decreased over time when the organisms were exposed to repeated freezing. The results therefore suggest that carbohydrate resources are important as a fuel for E. albidus during freezing whereas lipid resources are of marginal importance.
PubMed ID
25214492 View in PubMed
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Evidence for human-mediated dispersal of exotic earthworms: support for exploring strategies to limit further spread.

https://arctichealth.org/en/permalink/ahliterature158602
Source
Mol Ecol. 2008 Mar;17(5):1165-7
Publication Type
Article
Date
Mar-2008
Author
Cindy M Hale
Author Affiliation
The Natural Resources Research Institute, Center for Water and the Environment, University of Minnesota, Duluth, MN 55811, USA. cmhale@d.umn.edu
Source
Mol Ecol. 2008 Mar;17(5):1165-7
Date
Mar-2008
Language
English
Publication Type
Article
Keywords
Alberta
Animals
Ecosystem
Geography
Haplotypes
Human Activities
Humans
Oligochaeta - physiology
Population Dynamics
Abstract
As potent ecosystem engineers, non-native earthworms are altering the fundamental structure and function of previously earthworm-free cold-temperate hardwood forests in North America. Discarded earthworms used for fishing bait has been presumed to be an important vector for the continued spread of non-native earthworms because epicentres of invasion often include boat landings, lakeshores and roads. However, controversy has remained about the overall importance of human-mediated spread vs. natural expansion of established earthworm populations. In this issue of Molecular Ecology, Cameron et al. explore the continued role of humans in dispersing non-native earthworms.
Notes
Comment On: Mol Ecol. 2008 Mar;17(5):1189-9718179429
PubMed ID
18302681 View in PubMed
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Invasive earthworms unlock arctic plant nitrogen limitation.

https://arctichealth.org/en/permalink/ahliterature306285
Source
Nat Commun. 2020 04 14; 11(1):1766
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
04-14-2020
Author
Gesche Blume-Werry
Eveline J Krab
Johan Olofsson
Maja K Sundqvist
Maria Väisänen
Jonatan Klaminder
Author Affiliation
Experimental Plant Ecology, Institute of Botany and Landscape Ecology, University of Greifswald, Soldmannstraße 15, 17487, Greifswald, Germany.
Source
Nat Commun. 2020 04 14; 11(1):1766
Date
04-14-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Arctic Regions
Ecosystem
Nitrogen - metabolism
Oligochaeta - physiology
Plant Roots - physiology
Plant Shoots - physiology
Plants - metabolism
Poaceae
Abstract
Arctic plant growth is predominantly nitrogen (N) limited. This limitation is generally attributed to slow soil microbial processes due to low temperatures. Here, we show that arctic plant-soil N cycling is also substantially constrained by the lack of larger detritivores (earthworms) able to mineralize and physically translocate litter and soil organic matter. These new functions provided by earthworms increased shrub and grass N concentration in our common garden experiment. Earthworm activity also increased either the height or number of floral shoots, while enhancing fine root production and vegetation greenness in heath and meadow communities to a level that exceeded the inherent differences between these two common arctic plant communities. Moreover, these worming effects on plant N and greening exceeded reported effects of warming, herbivory and nutrient addition, suggesting that human spreading of earthworms may lead to substantial changes in the structure and function of arctic ecosystems.
PubMed ID
32286301 View in PubMed
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Selection of focal earthworm species as non-target soil organisms for environmental risk assessment of genetically modified plants.

https://arctichealth.org/en/permalink/ahliterature276536
Source
Sci Total Environ. 2016 Apr 1;548-549:360-9
Publication Type
Article
Date
Apr-1-2016
Author
Christine van Capelle
Stefan Schrader
Salvatore Arpaia
Source
Sci Total Environ. 2016 Apr 1;548-549:360-9
Date
Apr-1-2016
Language
English
Publication Type
Article
Keywords
Animals
Environmental Monitoring - methods
Ireland
Oligochaeta - physiology
Plants, Genetically Modified - toxicity
Risk assessment
Soil
Soil Pollutants - toxicity
Spain
Sweden
Abstract
By means of a literature survey, earthworm species of significant relevance for soil functions in different biogeographical regions of Europe (Atlantic, Boreal, Mediterranean) were identified. These focal earthworm species, defined here according to the EFSA Guidance Document on the environmental risk assessment (ERA) of genetically modified plants, are typical for arable soils under crop rotations with maize and/or potatoes within the three regions represented by Ireland, Sweden and Spain, respectively. Focal earthworm species were selected following a matrix of four steps: Identification of functional groups, categorization of non-target species, ranking species on ecological criteria, and final selection of focal species. They are recommended as appropriate non-target organisms to assess environmental risks of genetically modified (GM) crops; in this case maize and potatoes. In total, 44 literature sources on earthworms in arable cropping systems including maize or potato from Ireland, Sweden and Spain were collected, which present information on species diversity, individual density and specific relevance for soil functions. By means of condensed literature data, those species were identified which (i) play an important functional role in respective soil systems, (ii) are well adapted to the biogeographical regions, (iii) are expected to occur in high abundances under cultivation of maize or potato and (iv) fulfill the requirements for an ERA test system based on life-history traits. First, primary and secondary decomposers were identified as functional groups being exposed to the GM crops. In a second step, anecic and endogeic species were categorized as potential species. In step three, eight anecic and endogeic earthworm species belonging to the family Lumbricidae were ranked as relevant species: Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea longa, Allolobophora chlorotica, Lumbricus terrestris, Lumbricus friendi, Octodrilus complanatus and Octolasion cyaneum. Five out of these eight species are relevant for each biogeographical region with an overlap in the species. Finally, the earthworm species Ap. caliginosa (endogeic, secondary decomposer) and L. terrestris (anecic, primary decomposer) were selected as focal species. In the Mediterranean region L. terrestris may be substituted by the more relevant anecic species L. friendi. The selected focal species are recommended to be included in a standardized laboratory ERA test system based on life-history traits.
PubMed ID
26803734 View in PubMed
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