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15N in symbiotic fungi and plants estimates nitrogen and carbon flux rates in Arctic tundra.

https://arctichealth.org/en/permalink/ahliterature82286
Source
Ecology. 2006 Apr;87(4):816-22
Publication Type
Article
Date
Apr-2006
Author
Hobbie John E
Hobbie Erik A
Author Affiliation
The Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA. jhobbie@mbl.edu
Source
Ecology. 2006 Apr;87(4):816-22
Date
Apr-2006
Language
English
Publication Type
Article
Keywords
Arctic Regions
Carbon - metabolism
Fungi - metabolism
Nitrogen Isotopes - metabolism
Plants - metabolism
Abstract
When soil nitrogen is in short supply, most terrestrial plants form symbioses with fungi (mycorrhizae): hyphae take up soil nitrogen, transport it into plant roots, and receive plant sugars in return. In ecosystems, the transfers within the pathway fractionate nitrogen isotopes so that the natural abundance of 15N in fungi differs from that in their host plants by as much as 12% per hundred. Here we present a new method to quantify carbon and nitrogen fluxes in the symbiosis based on the fractionation against 15N during transfer of nitrogen from fungi to plant roots. We tested this method, which is based on the mass balance of 15N, with data from arctic Alaska where the nitrogen cycle is well studied. Mycorrhizal fungi provided 61-86% of the nitrogen in plants; plants provided 8-17% of their photosynthetic carbon to the fungi for growth and respiration. This method of analysis avoids the disturbance of the soil-microbe-root relationship caused by collecting samples, mixing the soil, or changing substrate concentrations. This analytical technique also can be applied to other nitrogen-limited ecosystems, such as many temperate and boreal forests, to quantify the importance for terrestrial carbon and nitrogen cycling of nutrient transfers mediated by mycorrhizae at the plant-soil interface.
PubMed ID
16676524 View in PubMed
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Analysing half-lives for pesticide dissipation in plants.

https://arctichealth.org/en/permalink/ahliterature269814
Source
SAR QSAR Environ Res. 2015;26(4):325-42
Publication Type
Article
Date
2015
Author
R E Jacobsen
P. Fantke
S. Trapp
Source
SAR QSAR Environ Res. 2015;26(4):325-42
Date
2015
Language
English
Publication Type
Article
Keywords
Biodegradation, Environmental
China
Denmark
Half-Life
Lycopersicon esculentum - metabolism
Models, Biological
Pesticide Residues - chemistry - metabolism
Pesticides - chemistry - metabolism
Plants - metabolism
Triticum - metabolism
Volatilization
Abstract
Overall dissipation of pesticides from plants is frequently measured, but the contribution of individual loss processes is largely unknown. We use a pesticide fate model for the quantification of dissipation by processes other than degradation. The model was parameterised using field studies. Scenarios were established for Copenhagen/Denmark and Shanghai/PR China, and calibrated with measured results. The simulated dissipation rates of 42 pesticides were then compared with measured overall dissipation from field studies using tomato and wheat. The difference between measured overall dissipation and calculated dissipation by non-degradative processes should ideally be contributable to degradation in plants. In 11% of the cases, calculated dissipation was above the measured dissipation. For the remaining cases, the non-explained dissipation ranged from 30% to 83%, depending on crop type, plant part and scenario. Accordingly, degradation is the most relevant dissipation process for these 42 pesticides, followed by growth dilution. Volatilisation was less relevant, which can be explained by the design of plant protection agents. Uptake of active compound from soil into plants leads to a negative dissipation process (i.e. a gain) that is difficult to quantify because it depends largely on interception, precipitation and plant stage. This process is particularly relevant for soluble compounds.
PubMed ID
25948099 View in PubMed
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Aquatic and terrestrial plant species with potential to remove heavy metals from storm-water.

https://arctichealth.org/en/permalink/ahliterature181764
Source
Int J Phytoremediation. 2003;5(3):211-24
Publication Type
Article
Date
2003
Author
Asa Fritioff
Maria Greger
Author Affiliation
Dept. of Botany, Stockholm University, S-10691 Stockholm, Sweden. fritioff@botan.su.se
Source
Int J Phytoremediation. 2003;5(3):211-24
Date
2003
Language
English
Publication Type
Article
Keywords
Ecosystem
Environmental pollution - prevention & control
Humans
Metals, Heavy - analysis - metabolism
Plant Roots
Plants - metabolism
Sweden
Water Pollutants, Chemical - analysis - metabolism
Water supply
Abstract
Remediation of storm-water polluted with heavy metals should be possible in percolation systems, ponds, or wetlands. The aim of this work was to find plant species for such systems that are efficient in the uptake of Zn, Cu, Cd, and Pb. Plants were collected from percolation and wetland areas and analyzed for heavy metal concentrations. Results showed that submersed and free-floating plants had the capacity to take up high levels of Cu, Zn, and Pb into their shoots. With roots having a concentration factor above 1, the terrestrial plants show efficient stabilization of Cd and Zn and emergent plants show corresponding stabilisation of Zn. In addition, Potamogeton natans, Alisma plantago-aquatica, and Filipendula ulmaria were used in a controlled experiment. The shoots of P. natans and the roots of A. plantago-aquatica were found to accumulate even higher concentrations of Zn, Cu, and Pb than found in the field-harvested plants. Similar results were found for Cd in shoots and Pb in roots of F. ulmaria. Our conclusion is that submersed plant species seem to be the most efficient for removal of heavy metals from storm-water.
PubMed ID
14750429 View in PubMed
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Arctic hydrology during global warming at the Palaeocene/Eocene thermal maximum.

https://arctichealth.org/en/permalink/ahliterature95711
Source
Nature. 2006 Aug 10;442(7103):671-5
Publication Type
Article
Date
Aug-10-2006
Author
Pagani Mark
Pedentchouk Nikolai
Huber Matthew
Sluijs Appy
Schouten Stefan
Brinkhuis Henk
Damsté Jaap S Sinninghe
Dickens Gerald R
Author Affiliation
Department of Geology and Geophysics, Yale University, PO Box 208109, New Haven, Connecticut 06520, USA. mark.pagani@yale.edu
Source
Nature. 2006 Aug 10;442(7103):671-5
Date
Aug-10-2006
Language
English
Publication Type
Article
Keywords
Alkanes - metabolism
Arctic Regions
Biological Markers - analysis
Calcium Carbonate - analysis - metabolism
Carbon - metabolism
Carbon Isotopes
Geologic Sediments - chemistry
Greenhouse Effect
History, Ancient
Humidity
Hydrogen - analysis - chemistry
Marine Biology
Oceans and Seas
Plants - metabolism
Rain
Seawater - analysis - chemistry
Sodium Chloride - analysis
Temperature
Time Factors
Abstract
The Palaeocene/Eocene thermal maximum represents a period of rapid, extreme global warming 55 million years ago, superimposed on an already warm world. This warming is associated with a severe shoaling of the ocean calcite compensation depth and a >2.5 per mil negative carbon isotope excursion in marine and soil carbonates. Together these observations indicate a massive release of 13C-depleted carbon and greenhouse-gas-induced warming. Recently, sediments were recovered from the central Arctic Ocean, providing the first opportunity to evaluate the environmental response at the North Pole at this time. Here we present stable hydrogen and carbon isotope measurements of terrestrial-plant- and aquatic-derived n-alkanes that record changes in hydrology, including surface water salinity and precipitation, and the global carbon cycle. Hydrogen isotope records are interpreted as documenting decreased rainout during moisture transport from lower latitudes and increased moisture delivery to the Arctic at the onset of the Palaeocene/Eocene thermal maximum, consistent with predictions of poleward storm track migrations during global warming. The terrestrial-plant carbon isotope excursion (about -4.5 to -6 per mil) is substantially larger than those of marine carbonates. Previously, this offset was explained by the physiological response of plants to increases in surface humidity. But this mechanism is not an effective explanation in this wet Arctic setting, leading us to hypothesize that the true magnitude of the excursion--and associated carbon input--was greater than originally surmised. Greater carbon release and strong hydrological cycle feedbacks may help explain the maintenance of this unprecedented warmth.
Notes
Erratum In: Nature. 2006 Oct 5;443(7111):598
PubMed ID
16906647 View in PubMed
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Arctic terrestrial ecosystem contamination.

https://arctichealth.org/en/permalink/ahliterature3575
Source
Sci Total Environ. 1992 Jul 15;122(1-2):135-64
Publication Type
Article
Date
Jul-15-1992
Author
D J Thomas
B. Tracey
H. Marshall
R J Norstrom
Author Affiliation
Axys Group Ltd, Sidney, British Columbia, Canada.
Source
Sci Total Environ. 1992 Jul 15;122(1-2):135-64
Date
Jul-15-1992
Language
English
Publication Type
Article
Keywords
Animals
Arctic Regions
Eggs - analysis
Humans
Hydrocarbons - analysis
Hydrocarbons, Chlorinated - analysis - pharmacokinetics
Metals - analysis
Mining
Petroleum
Plants - metabolism
Radioactive Pollutants - analysis - pharmacokinetics
Reindeer - metabolism
Soil Pollutants - analysis - pharmacokinetics
Abstract
Limited data have been collected on the presence of contaminants in the Arctic terrestrial ecosystem, with the exception of radioactive fallout from atmospheric weapons testing. Although southern and temperate biological systems have largely cleansed themselves of radioactive fallout deposited during the 1950s and 1960s, Arctic environments have not. Lichens accumulate radioactivity more than many other plants because of their large surface area and long life span; the presence and persistence of radioisotopes in the Arctic is of concern because of the lichen----reindeer----human ecosystem. Effective biological half-life of cesium 137 is reckoned to be substantially less than its physical half-life. The database on organochlorines in Canadian Arctic terrestrial mammals and birds is very limited, but indications are that the air/plant/animal contaminant pathway is the major route of these compounds into the terrestrial food chain. For terrestrial herbivores, the most abundant organochlorine is usually hexachlorobenzene followed by hexachlorocyclohexane isomers. PCB accumulation favours the hexachlorobiphenyl, pentachlorobiphenyl and heptachlorobiphenyl homologous series. The concentrations of the various classes of organochlorine compounds are substantially lower in terrestrial herbivore tissues than in marine mammal tissues. PCBs and DDT are the most abundant residues in peregrine falcons (a terrestrial carnivore) reaching average levels of 9.2 and 10.4 micrograms.g-1, respectively, more than 10 times higher than other organochlorines and higher than in marine mammals, including the polar bear. Contaminants from local sources include metals from mining activities, hydrocarbons and waste drilling fluids from oil and gas exploration and production, wastes from DEW line sites, naturally occurring radionuclides associated with uranium mineralization, and smoke containing SO2 and H2SO4 aerosol from the Smoking Hills at Cape Bathurst, N.W.T.
PubMed ID
1355310 View in PubMed
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Aryl hydrocarbon bioaccessibility to small mammals from arctic plants using in vitro techniques.

https://arctichealth.org/en/permalink/ahliterature78357
Source
Environ Toxicol Chem. 2007 Mar;26(3):491-6
Publication Type
Article
Date
Mar-2007
Author
Armstrong Sarah A
Van de Wiele Tom
Germida James J
Siciliano Steven D
Author Affiliation
Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan S7N 1H3, Canada.
Source
Environ Toxicol Chem. 2007 Mar;26(3):491-6
Date
Mar-2007
Language
English
Publication Type
Article
Keywords
Animals
Benzo(a)pyrene - metabolism
Digestion
Dioxins
Food chain
Hydrocarbons, Aromatic - analysis - pharmacokinetics
Mammals
Models, Biological
Plant Extracts
Plants - metabolism
Polycyclic Hydrocarbons, Aromatic
Receptors, Aryl Hydrocarbon - antagonists & inhibitors
Species Specificity
Abstract
Through their diet, herbivores inhabiting contaminated sites may be chronically exposed to a variety of aryl hydrocarbons (e.g., dioxins and polycyclic aromatic hydrocarbons [PAHs]). However, little is known about how differences in morphology and physiology among plant species alter the environmental accumulation of aryl hydrocarbons or their release and subsequent activity in the gastrointestinal tract of herbivores after ingestion. In the present study, the activity of aryl hydrocarbons during digestion was examined using six Arctic plant species growing in impacted and reference sites near Inuvik, Northwest Territories, Canada. The plant species studied were black spruce (Picea mariana), labrador tea (Ledum groenlandicum), bog birch (Betula glandulosa), green alder (Alnus crispa), water sedge (Carex aquatilis), and little-tree willow (Salix arbusculoides). Plants were digested using a simulator of the upper digestive tract, and aryl hydrocarbon release was evaluated using an aryl hydrocarbon-receptor assay. Bioaccessible aryl hydrocarbon activity varied among the plant species tested. The species with the greatest activity was green alder, and the species with the least activity was black spruce. Further investigation revealed that digested plant extracts may antagonize the aryl hydrocarbon receptor and prevent bioactivation of the aryl compound benzo[a]pyrene. Thus, PAH risk from the ingestion of vegetation varies among plant species and may depend on antagonists present in the vegetation.
PubMed ID
17373513 View in PubMed
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Biotic responses buffer warming-induced soil organic carbon loss in Arctic tundra.

https://arctichealth.org/en/permalink/ahliterature297735
Source
Glob Chang Biol. 2018 10; 24(10):4946-4959
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
10-2018
Author
Junyi Liang
Jiangyang Xia
Zheng Shi
Lifen Jiang
Shuang Ma
Xingjie Lu
Marguerite Mauritz
Susan M Natali
Elaine Pegoraro
Christopher Ryan Penton
César Plaza
Verity G Salmon
Gerardo Celis
James R Cole
Konstantinos T Konstantinidis
James M Tiedje
Jizhong Zhou
Edward A G Schuur
Yiqi Luo
Author Affiliation
Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma.
Source
Glob Chang Biol. 2018 10; 24(10):4946-4959
Date
10-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Alaska
Carbon - analysis - metabolism
Climate change
Models, Theoretical
Permafrost - chemistry - microbiology
Photosynthesis
Plants - metabolism
Soil - chemistry
Soil Microbiology
Tundra
Abstract
Climate warming can result in both abiotic (e.g., permafrost thaw) and biotic (e.g., microbial functional genes) changes in Arctic tundra. Recent research has incorporated dynamic permafrost thaw in Earth system models (ESMs) and indicates that Arctic tundra could be a significant future carbon (C) source due to the enhanced decomposition of thawed deep soil C. However, warming-induced biotic changes may influence biologically related parameters and the consequent projections in ESMs. How model parameters associated with biotic responses will change under warming and to what extent these changes affect projected C budgets have not been carefully examined. In this study, we synthesized six data sets over 5 years from a soil warming experiment at the Eight Mile Lake, Alaska, into the Terrestrial ECOsystem (TECO) model with a probabilistic inversion approach. The TECO model used multiple soil layers to track dynamics of thawed soil under different treatments. Our results show that warming increased light use efficiency of vegetation photosynthesis but decreased baseline (i.e., environment-corrected) turnover rates of SOC in both the fast and slow pools in comparison with those under control. Moreover, the parameter changes generally amplified over time, suggesting processes of gradual physiological acclimation and functional gene shifts of both plants and microbes. The TECO model predicted that field warming from 2009 to 2013 resulted in cumulative C losses of 224 or 87 g/m2 , respectively, without or with changes in those parameters. Thus, warming-induced parameter changes reduced predicted soil C loss by 61%. Our study suggests that it is critical to incorporate biotic changes in ESMs to improve the model performance in predicting C dynamics in permafrost regions.
PubMed ID
29802797 View in PubMed
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Climate Change 2007: a world melting from the top down.

https://arctichealth.org/en/permalink/ahliterature95640
Source
Nature. 2007 Apr 12;446(7137):718-221
Publication Type
Article
Date
Apr-12-2007

Consistency of gas exchange of man and plants in a closed ecological system: lines of attack on the problem.

https://arctichealth.org/en/permalink/ahliterature62006
Source
Adv Space Res. 1996;18(1-2):205-10
Publication Type
Article
Date
1996
Author
J I Gitelson
Okladnikov YuN
Author Affiliation
Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, Russia.
Source
Adv Space Res. 1996;18(1-2):205-10
Date
1996
Language
English
Publication Type
Article
Keywords
Atmosphere
Carbon Dioxide - metabolism
Ecological Systems, Closed
Humans
Models, Biological
Nutrition
Oxygen - metabolism
Photosynthesis - physiology
Plant Physiology
Plants - metabolism
Respiration
Abstract
Gas exchange between man and plants in a closed ecological system based on atmosphere regeneration by plant photosynthesis is made consistent by attaining the equilibrium of human CO2 discharge and the productivity of the gas consuming bioregenerator. In this case the gas exchange might be, however, qualitatively disturbed from the equilibrium in terms of oxygen making it accumulate or decrease continuously in the air of the system. Gas exchange equilibrium in terms of O2 was attained in long-term experiments by equality of the human respiration coefficient and the plant assimilation coefficient. Varying the ratio of these parameters it is possible to control the oxygen concentration in the atmosphere to be reclaimed.
PubMed ID
11538965 View in PubMed
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Decreasing snow cover alters functional composition and diversity of Arctic tundra.

https://arctichealth.org/en/permalink/ahliterature305088
Source
Proc Natl Acad Sci U S A. 2020 09 01; 117(35):21480-21487
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
09-01-2020
Author
Pekka Niittynen
Risto K Heikkinen
Miska Luoto
Author Affiliation
Department of Geosciences and Geography, University of Helsinki, FIN-00014 Helsinki, Finland; pekka.niittynen@helsinki.fi.
Source
Proc Natl Acad Sci U S A. 2020 09 01; 117(35):21480-21487
Date
09-01-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Arctic Regions
Biodiversity
Climate change
Cold Temperature - adverse effects
Ecosystem
Plant Leaves - metabolism
Plants - metabolism
Seasons
Snow
Temperature
Tundra
Abstract
The Arctic is one of the least human-impacted parts of the world, but, in turn, tundra biome is facing the most rapid climate change on Earth. These perturbations may cause major reshuffling of Arctic species compositions and functional trait profiles and diversity, thereby affecting ecosystem processes of the whole tundra region. Earlier research has detected important drivers of the change in plant functional traits under warming climate, but studies on one key factor, snow cover, are almost totally lacking. Here we integrate plot-scale vegetation data with detailed climate and snow information using machine learning methods to model the responsiveness of tundra communities to different scenarios of warming and snow cover duration. Our results show that decreasing snow cover, together with warming temperatures, can substantially modify biotic communities and their trait compositions, with future plant communities projected to be occupied by taller plants with larger leaves and faster resource acquisition strategies. As another finding, we show that, while the local functional diversity may increase, simultaneous biotic homogenization across tundra communities is likely to occur. The manifestation of climate warming on tundra vegetation is highly dependent on the evolution of snow conditions. Given this, realistic assessments of future ecosystem functioning require acknowledging the role of snow in tundra vegetation models.
PubMed ID
32778575 View in PubMed
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41 records – page 1 of 5.