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Zhao R, Shang Y, Jacinthe PA, Li S, Liu G, Wen Z, Wang Z, Yang Q, Fang C, Song K. Variations in surface area and biogeochemistry of subarctic-arctic lakes established through satellite and in-situ observations: An overview of published research from the past 30 years. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172797. [PMID: 38679084 DOI: 10.1016/j.scitotenv.2024.172797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/03/2024] [Accepted: 04/24/2024] [Indexed: 05/01/2024]
Abstract
Human activities have strongly impacted the global climate, and during the last few decades the global average temperature has risen at a rate faster than at any time on record. High latitude lakes in the subarctic and arctic permafrost regions have particularly been vulnerable given the "Arctic amplification" phenomenon and acceleration in warming rate in the northern hemisphere (0.2-0.8 °C/decade). This paper presents a comprehensive overview of the last 30 years of research investigating how subarctic and Arctic lakes respond to climate warming. The review focused on studies where remote sensing technology was used to quantify these responses. The difference between summer lake water temperature and air temperature varied between 1.7 and 5.4 °C in subarctic lakes and 2.4-3.2 °C in Arctic lakes. Overall, the freezing date of lake ice is generally delayed and the date of lake thawing occurs earlier. Lake surface area (4-48.5 %), and abundance in the subarctic and Arctic region have increased significantly due to rising temperature, permafrost thawing, increased precipitation and other localized surface disturbances. However, in recent years, instances of lake shrinkage (between -0.4 % and -40 %) have also been reported, likely due to riparian overflow, groundwater infiltration and lateral drainage. Furthermore, in subarctic and Arctic lakes, climate change and permafrost thawing would release CO2 and CH4, and alter carbon dynamics in impacted lakes through various interconnected processes which could potentially affect the quality of carbon (terrestrial, algae) entering a lake system. The review also highlighted a potential intersection between permafrost melting and public health through human exposure to long-buried viruses. Subarctic and arctic ecosystems' responses to climate change will continue to be an area of intense research interest, and this review has highlighted priority areas for research and how remote sensing technologies can facilitate the pursuit of such a research agenda.
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Affiliation(s)
- Ruixue Zhao
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; School of Geomatics and Prospecting Engineering, Jilin Jianzhu University, Changchun 130118, China
| | - Yingxin Shang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Pierre-André Jacinthe
- Department of Earth Sciences, Indiana University-Purdue University, Indianapolis, IN 46202, USA
| | - Sijia Li
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Ge Liu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Zhidan Wen
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Zijin Wang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Qian Yang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Chong Fang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Kaishan Song
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; School of Environment and Planning, Liaocheng University, Liaocheng 252000, China.
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Powers LC, Schmitt-Kopplin P, Gonsior M. Evaluating the photochemical reactivity of disinfection byproducts formed during seawater desalination processes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169292. [PMID: 38104835 DOI: 10.1016/j.scitotenv.2023.169292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/04/2023] [Accepted: 12/09/2023] [Indexed: 12/19/2023]
Abstract
Reverse osmosis (RO) is widely used for seawater desalination but pre-chlorination of intake water produces halogenated disinfection byproducts (DBPs). The fate and environmental impacts associated with the discharge of DBP-containing RO brine wastewater are unknown. Therefore, to evaluate if photochemistry plays a role in DBP degradation in seawater, we collected samples at a desalination plant, which were desalted and concentrated using two-inline solid phase extraction (SPE) techniques combining reverse-phase polymeric (PPL) and weak anion exchange (WAX) resins. Both filtered water samples and SPE samples (extracts reconstituted in open ocean seawater) were exposed to simulated sunlight in a custom-built flow-through system. Optical property analysis during irradiation experiments did not provide distinguishing features between intake water and RO reject water (brine). Extractable organic bromine (organoBr) concentrations were low in intake water samples (7.8 μg Br L-1) and did not change significantly due to irradiation. OrganoBr concentrations in laboratory-chlorinated raw water were much higher (135 μg Br L-1) and on average decreased by 42 % after 24 h irradiation. However, while organoBr concentrations were highest in RO reject water (473 μg Br L-1), changes in organoBr concentrations in PPL SPE samples after 24 h irradiation were variable, ranging from a 1-46 % loss. Furthermore, most bromine-containing molecular ions identified by high resolution mass spectrometry that were present in RO reject water before irradiation were also found after both 24 h and 50 h exposures. Although only one RO reject water sample was tested in this study, results highlight that hundreds of yet to be identified brominated DBPs in RO reject water could be resistant to photodegradation or phototransform into existing DBPs in the environment. Future work examining the biolability of DBPs in RO reject water, as well as the interplay between photochemical and biological DBP cycling, is warranted.
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Affiliation(s)
- Leanne C Powers
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States.
| | - Philippe Schmitt-Kopplin
- Helmholtz Munich, Research Unit Analytical BioGeoChemistry, Munich, Germany; Chair of Analytical Food Chemistry, Technical University München, Munich, Germany; Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, United States
| | - Michael Gonsior
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, United States
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Silva I, Alves M, Malheiro C, Silva ARR, Loureiro S, Henriques I, González-Alcaraz MN. Structural and Functional Shifts in the Microbial Community of a Heavy Metal-Contaminated Soil Exposed to Short-Term Changes in Air Temperature, Soil Moisture and UV Radiation. Genes (Basel) 2024; 15:107. [PMID: 38254996 PMCID: PMC10815596 DOI: 10.3390/genes15010107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/11/2024] [Accepted: 01/14/2024] [Indexed: 01/24/2024] Open
Abstract
The interplay between metal contamination and climate change may exacerbate the negative impact on the soil microbiome and, consequently, on soil health and ecosystem services. We assessed the response of the microbial community of a heavy metal-contaminated soil when exposed to short-term (48 h) variations in air temperature, soil humidity or ultraviolet (UV) radiation in the absence and presence of Enchytraeus crypticus (soil invertebrate). Each of the climate scenarios simulated significantly altered at least one of the microbial parameters measured. Irrespective of the presence or absence of invertebrates, the effects were particularly marked upon exposure to increased air temperature and alterations in soil moisture levels (drought and flood scenarios). The observed effects can be partly explained by significant alterations in soil properties such as pH, dissolved organic carbon, and water-extractable heavy metals, which were observed for all scenarios in comparison to standard conditions. The occurrence of invertebrates mitigated some of the impacts observed on the soil microbial community, particularly in bacterial abundance, richness, diversity, and metabolic activity. Our findings emphasize the importance of considering the interplay between climate change, anthropogenic pressures, and soil biotic components to assess the impact of climate change on terrestrial ecosystems and to develop and implement effective management strategies.
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Affiliation(s)
- Isabel Silva
- CEF (Center for Functional Ecology), Associate Laboratory TERRA, Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000-456 Coimbra, Portugal;
- CESAM (Centre for Marine and Environmental Studies), Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal; (C.M.); (A.R.R.S.); (S.L.)
| | - Marta Alves
- CBQF (Center for Biotechnology and Fine Chemistry), School of Biotechnology, Portuguese Catholic University, 4169-005 Porto, Portugal;
| | - Catarina Malheiro
- CESAM (Centre for Marine and Environmental Studies), Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal; (C.M.); (A.R.R.S.); (S.L.)
| | - Ana Rita R. Silva
- CESAM (Centre for Marine and Environmental Studies), Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal; (C.M.); (A.R.R.S.); (S.L.)
| | - Susana Loureiro
- CESAM (Centre for Marine and Environmental Studies), Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal; (C.M.); (A.R.R.S.); (S.L.)
| | - Isabel Henriques
- CEF (Center for Functional Ecology), Associate Laboratory TERRA, Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000-456 Coimbra, Portugal;
| | - M. Nazaret González-Alcaraz
- CESAM (Centre for Marine and Environmental Studies), Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal; (C.M.); (A.R.R.S.); (S.L.)
- Department of Agricultural Engineering of the E.T.S.I.A., Technical University of Cartagena, 30203 Cartagena, Spain
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Zhu WZ, Wang SH, Wang DZ, Feng WH, Li B, Zhang HH. Contrasting effects of different light regimes on the photoreactivities of allochthonous and autochthonous chromophoric dissolved organic matter. CHEMOSPHERE 2023; 332:138823. [PMID: 37232197 DOI: 10.1016/j.chemosphere.2023.138823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/27/2023]
Abstract
Chromophoric dissolved organic matter (CDOM) plays an important role in ultraviolet (UV) light absorption in the ocean. CDOM is known to originate from either an allochthonous or autochthonous source and has varying compositions and levels of reactivity; however, the effects of individual radiation treatments and the combined effects of UVA and UVB on allochthonous and autochthonous CDOM remain poorly understood. Thus, here, we measured changes in the common optical properties of CDOM collected from China's marginal seas and the Northwest Pacific, using full-spectrum, UVA (315-400 nm), and UVB (280-315 nm) irradiation to induce photodegradation over the same time period (60 h). Excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC) identified four components: marine humic-like C1, terrestrial humic-like C2, soil fulvic-like C3, and tryptophan-like C4. Although the behaviours of these components during full-spectrum irradiation exhibited similar decreasing tendencies, three components (C1, C3, and C4) underwent direct photodegradation under UVB exposure, whereas C2 was more susceptible to UVA degradation. The diverse photoreactivities of the source-dependent components to different light treatments led to differing photochemical behaviours of other optical indices [aCDOM(355), aCDOM(254), SR, HIX, and BIX]. The results indicate that irradiation preferentially reduced the high humification degree or humic substance content of allochthonous DOM, and promoted the transformation from the allochthonous humic DOM components to recently produced components. Although values for the samples from different sources overlapped frequently, principal component analysis (PCA) indicated that the overall optical signatures could be linked to the original CDOM source features. The degradation of CDOM humification, aromaticity, molecular weight, and autochthonous fractions under exposure can drive the CDOM biogeochemical cycle in marine environments. These findings can aid in a better understanding of the effects of different combinations of light treatments and CDOM characteristics on CDOM photochemical processes.
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Affiliation(s)
- Wen-Zhuo Zhu
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, China
| | - Shu-Heng Wang
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, China
| | - De-Zhong Wang
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, China
| | - Wei-Hua Feng
- Key Laboratory of Engineering Oceanography, Second Institute of Oceanography, Ministry of Natural Resource of the People' s Republic of China, Hangzhou, 310012, China
| | - Bo Li
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, China; Donghai Laboratory, Zhoushan, 316021, China.
| | - Hong-Hai Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
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Wang Y, Ma J. Charge transfer interactions exist in extracellular polymeric substances: Comparison with natural organic matter. CHEMOSPHERE 2023:139030. [PMID: 37236282 DOI: 10.1016/j.chemosphere.2023.139030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 05/28/2023]
Abstract
Extracellular polymeric substances (EPS) and natural organic matter (NOM) are widely present in the environment. While the molecular basis of NOM's optical properties and reactivity after treatment with sodium borohydride (NaBH4) has been successfully explained by the charge transfer (CT) model, the corresponding structure basis and properties of EPS remain poorly understood. In this work, we investigated the reactivity and optical properties of EPS after NaBH4 treatment, comparing them to the corresponding changes in NOM. After reduction, EPS exhibited optical properties and a reactivity with Au3+ similar to NOM, manifesting an irreversible loss of visible absorption (≥70%) associated with blue-shifted fluorescence emission (8-11 nm) and a lower rate of gold nanoparticles formation (decreasing by ≥ 32%), which can be readily explained by the CT model as well. Furthermore, the absorbance and fluorescence spectra of EPS were solvent polarity dependent, contrary to the superposition model. These findings contribute to an original understanding of the reactivity and optical properties of EPS and facilitate further cross-disciplinary studies.
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Affiliation(s)
- Ya Wang
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jiahai Ma
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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Decomposition stages as a clue for estimating the post-mortem interval in carcasses and providing accurate bird collision rates. Sci Rep 2022; 12:16188. [PMID: 36171410 PMCID: PMC9519910 DOI: 10.1038/s41598-022-20628-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
The estimation of the post-mortem interval is crucial to accurately provide bird collision rates against manmade infrastructures. Standard methodologies recommend initially clearing all carcasses to ensure that subsequent collisions can be attributed to known time intervals. In this study, we propose a more cost-efficient approach aiming to link the decomposition stages as unequivocally as possible to the most likely time elapsed since death. Factors influencing the decomposition stages of bird carcasses were evaluated by means of two experiments. Firstly, we examined carcasses of large birds in three seasons differing in temperature, sun radiation and humidity: summer, autumn and spring. Secondly, we tested the influence of body mass in the same season (spring) using small, medium-sized and large bird carcasses. Results showed that the decomposition score increased monotonically with time, attaining the highest magnitude effect. A carcass with a decomposition score ≥ 4 (skeletal reduction) was in the field for ≥ 15 days, whereas a carcass with a score < 3 (fresh or emphysematous) was exposed < 3 days. Decomposition scores were higher in summer and did not differ among carcass sizes. This study provides an alternative protocol to estimate the post-mortem interval in wild birds in studies in search of bird fatalities.
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Wang Y, Lee Z, Ondrusek M, Li X, Zhang S, Wu J. An evaluation of remote sensing algorithms for the estimation of diffuse attenuation coefficients in the ultraviolet bands. OPTICS EXPRESS 2022; 30:6640-6655. [PMID: 35299445 DOI: 10.1364/oe.446114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
In this study, six algorithms (both empirical and semi-analytical) developed for the estimation of Kd in the ultraviolet (UV) domain (specifically 360, 380, and 400 nm) were evaluated from a dataset of 316 stations covering oligotrophic ocean and coastal waters. In particular, the semi-analytical algorithm (Lee et al. 2013) used remote sensing reflectance in these near-blue UV bands estimated from a recently developed deep learning system as the input. For Kd(380) in a range of 0.018 - 2.34 m-1, it is found that the semi-analytical algorithm has the best performance, where the mean absolute relative difference (MARD) is 0.19, and the coefficient of determination (R2) is 0.94. For the empirical algorithms, the MARD values are 0.23-0.90, with R2 as 0.70-0.92, for this evaluation dataset. For a VIIRS and in situ matchup dataset (N = 62), the MARD of Kd(380) is 0.21 (R2 as 0.94) by the semi-analytical algorithm. These results indicate that a combination of deep learning system and semi-analytical algorithms can provide reliable Kd(UV) for past and present satellite ocean color missions that have no spectral bands in the UV, where global Kd(UV) products are required for comprehensive studies of UV radiation on marine primary productivity and biogeochemical processes in the ocean.
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Le Roux DM, Powers LC, Blough NV. Photoproduction Rates of One-Electron Reductants by Chromophoric Dissolved Organic Matter via Fluorescence Spectroscopy: Comparison with Superoxide and Hydrogen Peroxide Rates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12095-12105. [PMID: 34383497 DOI: 10.1021/acs.est.1c04043] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
One-electron reductants (OER) photoproduced by chromophoric dissolved organic matter (CDOM) have been shown to be likely precursors for the formation of superoxide and subsequently hydrogen peroxide. An improved method that employs a nitroxide radical probe (3AP) has been developed and utilized to determine the photoproduction rates of OER from a diverse set of CDOM samples. 3AP reacts with OER to produce the hydroxylamine, which is then derivatized with fluorescamine and quantified spectrofluorometrically. Although less sensitive than traditional methods for measuring RO2•-, measuring RH provides a simpler and faster method of estimating RO2•- and is amenable to continuous measurement via flow injection analysis. Production rates of OER (RH), superoxide (RO2•-), and hydrogen peroxide (RH2O2) have a similar wavelength dependence, indicating a common origin. If all the OER react with molecular oxygen to produce superoxide, then the simplest mechanism predicts that RH/RH2O2 and RO2•-/RH2O2 should be equal to 2. However, our measurements reveal RH/RH2O2 values as high as 16 (5.7-16), consistent with prior results, and RO2•-/RH2O2 values as high as 8 (5.4-8.2). These results indicate that a substantial fraction of superoxide (65-88%) is not undergoing dismutation. A reasonable oxidative sink for superoxide is reaction with photoproduced phenoxy radicals within CDOM.
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Affiliation(s)
- Danielle M Le Roux
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Leanne C Powers
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, Maryland 20688, United States
| | - Neil V Blough
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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da Rosa Wieliczko A, Crossetti LO, Cavalcanti JR, Hessel MS, da Motta-Marques D, Rodrigues LR. Meteorological drivers and ENSO influence on phytoplankton biomass dynamics in a shallow subtropical lake. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:536. [PMID: 34328576 DOI: 10.1007/s10661-021-09288-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Meteorological features influence the dynamics of aquatic ecosystems and consequently their biotas. This study aimed to identify the meteorological drivers of phytoplankton biomass (chlorophyll a), sampled seasonally over a period of 12 years (2001-2013) in Lake Mangueira, a large shallow subtropical lake in southern Brazil. The lake is 90 km long and 3-10 km wide with a mean depth of 3 m and is oligo-mesotrophic and highly affected by wind action. In general, non-parametric multiplicative regression analysis identified wind direction, radiation, and the Oceanic Niño Index as the main drivers of variation in chlorophyll a. Notably, ENSO periods caused changes in physical, chemical, and meteorological parameters, including conductivity, total suspended solids, total and dissolved nitrogen, alkalinity, soluble reactive silica, wind speed, and precipitation. Phytoplankton biomass showed significant differences between ENSO periods and the periods without events, occurring in the highest values during La Niña years. This study showed that meteorological variables can significantly influence productivity patterns, indicating the importance of including them in limnological studies.
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Affiliation(s)
- Andressa da Rosa Wieliczko
- Instituto de Pesquisas Hidráulicas, Universidade Federal Do Rio Grande Do Sul, Caixa Postal 15029, RS, 91501-970, Porto Alegre, Brazil.
| | - Luciane Oliveira Crossetti
- Departamento de Ecologia, Instituto de Biociências, Av. Bento Gonçalves 9500, AgronomiaPorto Alegre, RS, 91501-970, Brazil
| | - J Rafael Cavalcanti
- Instituto de Pesquisas Hidráulicas, Universidade Federal Do Rio Grande Do Sul, Caixa Postal 15029, RS, 91501-970, Porto Alegre, Brazil
| | - Mônica Silveira Hessel
- Instituto de Pesquisas Hidráulicas, Universidade Federal Do Rio Grande Do Sul, Caixa Postal 15029, RS, 91501-970, Porto Alegre, Brazil
| | - David da Motta-Marques
- Instituto de Pesquisas Hidráulicas, Universidade Federal Do Rio Grande Do Sul, Caixa Postal 15029, RS, 91501-970, Porto Alegre, Brazil
| | - Lucia Ribeiro Rodrigues
- Instituto de Pesquisas Hidráulicas, Universidade Federal Do Rio Grande Do Sul, Caixa Postal 15029, RS, 91501-970, Porto Alegre, Brazil
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Wang Y, Ma J. Quantitative determination of redox-active carbonyls of natural dissolved organic matter. WATER RESEARCH 2020; 185:116142. [PMID: 32823193 DOI: 10.1016/j.watres.2020.116142] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Natural dissolved organic matter (DOM) is ubiquitous in environment and plays an important role in numerous environmental processes. Although the molecular basis of the reactivity of DOM remains poorly understood due to its extreme complexity, redox-active carbonyls (aromatic ketones/aldehydes and quinones) within DOM are believed vitally important. Except the rough determination of total carbonyls (including non-redox active -COOR) based on inflexible 13C chemical shift range by expensive and time-consuming solid-state nuclear magnetic resonance (NMR), there is no ready method to quantify redox-active carbonyls in DOM. Here we show that after treatment with sodium borohydride (NaBH4) by selectively eliminating redox-active carbonyls, quenched fluorescence of carbon quantum dots (CD) by DOM recovered dramatically, and displayed a good linear relationship between redox-active carbonyls detected and DOM concentration (R2 ≥ 0.977), thus allowing first quantitative determination of the redox-active carbonyls of DOM. Eight DOM isolates present 0.59%-0.90% redox-active carbonyls by the current method. And this method is robust from coexisting proteins and salts. This method could provide better or equal instructive results compared with solid-state NMR for total carbonyls or electrochemical method for electron-accepting capacities (EAC). Our results provide the underlying structural basis of many important geochemical processes that mediated by DOM. We posit that this method could apply to other complex molecular systems such as the atmospheric aerosols and extracellular polymeric substances (EPS), too.
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Affiliation(s)
- Ya Wang
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiahai Ma
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Hiraki H, Watanabe M, Uemura M, Kawamura Y. Season specificity in the cold-induced calcium signal and the volatile chemicals in the atmosphere. PHYSIOLOGIA PLANTARUM 2020; 168:803-818. [PMID: 31390065 DOI: 10.1111/ppl.13019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 07/12/2019] [Accepted: 08/02/2019] [Indexed: 06/10/2023]
Abstract
Cold-induced Ca2+ signals in plants are widely accepted to be involved in cold acclimation. Surprisingly, despite using Arabidopsis plants grown in a growth chamber, we observed a clear seasonal change in cold-induced Ca2+ signals only in roots. Ca2+ signals were captured using Arabidopsis expressing Yellow Cameleon 3.60. In winter, two Ca2+ signal peaks were observed during a cooling treatment from 20 to 0°C, but in summer only one small peak was observed under the same cooling condition. In the spring and autumn seasons, an intermediate type of Ca2+ signal, which had a delayed first peak and smaller second peaks compared with the those of the winter type, was observed. Volatile chemicals and/or particles in the air from the outside may affect plants in the growth chamber. This idea is supported by the fact that incubation of plants with activated carbon changed the intermediate-type Ca2+ signal to the summer-type. The seasonality was also observed in the freezing tolerance of plants cold-acclimated in a low-temperature chamber. The solar radiation intensity was weakly correlated, not only with the seasonal characteristics of the Ca2+ signal but also with freezing tolerance. It has been reported that the ethylene concentration in the atmosphere seasonally changes depending on the solar radiation intensity. Ethylene gas and 1-aminocyclopropane-1-carboxylic acid treatment affected the Ca2+ signals, the shape of which became a shape close to, but not the same as, the winter type from the other types, indicating that ethylene may be one of several factors influencing the cold-induced Ca2+ signal.
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Affiliation(s)
- Hayato Hiraki
- The United Graduate School of Agricultural Sciences, Iwate University, Iwate, 020-8550, Japan
| | - Manabu Watanabe
- Field Science Center, Faculty of Agriculture, Iwate University, Iwate, 020-0611, Japan
| | - Matsuo Uemura
- The United Graduate School of Agricultural Sciences, Iwate University, Iwate, 020-8550, Japan
- Department of Plant Bioscience, Iwate University, Iwate, 020-8550, Japan
| | - Yukio Kawamura
- The United Graduate School of Agricultural Sciences, Iwate University, Iwate, 020-8550, Japan
- Department of Plant Bioscience, Iwate University, Iwate, 020-8550, Japan
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12
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Characteristics and Source of Dissolved Organic Matter in Lake Hulun, A Large Shallow Eutrophic Steppe Lake in Northern China. WATER 2020. [DOI: 10.3390/w12040953] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lake Hulun, the fifth largest lake in China, is a typical eutrophic steppe lake located in the Hulun Buir Prairie. The dissolved organic matter (DOM) in the water of Lake Hulun has a high concentration. However, little is known about the occurrence characteristics and source of the DOM in Lake Hulun. The spatial and temporal distribution characteristics of DOM concentration in Lake Hulun were thoroughly surveyed, and the optical characteristics, fluorescence components and sources of DOM were analyzed by excitation emission matrix (EMM) and parallel factor analysis (PARAFAC) technology. The DOM concentration was 6.46–42.87 mg C/L, and was highest in summer and lowest in winter. The difference in the spatial distribution of DOM in winter was significant due to the ice over, and showed a trend where the concentration near the shore was higher than that in the center of the lake. Three humic-like components and one component consisting of a mixture of humic-like and protein-like substances of DOM were identified, with the former being prevalent. The humification index of DOM was 2.22–9.92, indicating that the DOM has a high degree of humification. The DOM is mainly derived from terrestrial sources, with the highest proportion (91.0% ± 8.1%) found in winter and the lowest (66.2% ± 7.7%) in summer. Given that the DOM in Lake Hulun is mainly dominated by humic-like components with a high degree humification, the DOM may have low bioactivity. However, this is just a preliminary analysis and judgment, and it is necessary to conduct other experiments such as biodegradation experiments to further study the bioavailability of DOM in Lake Hulun.
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13
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Contribution of ketone/aldehyde-containing compounds to the composition and optical properties of Suwannee River fulvic acid revealed by ultrahigh resolution mass spectrometry and deuterium labeling. Anal Bioanal Chem 2020; 412:1441-1451. [DOI: 10.1007/s00216-019-02377-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/10/2019] [Accepted: 12/23/2019] [Indexed: 12/23/2022]
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14
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Chen Y, Arnold WA, Griffin CG, Olmanson LG, Brezonik PL, Hozalski RM. Assessment of the chlorine demand and disinfection byproduct formation potential of surface waters via satellite remote sensing. WATER RESEARCH 2019; 165:115001. [PMID: 31470281 DOI: 10.1016/j.watres.2019.115001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/14/2019] [Accepted: 08/18/2019] [Indexed: 06/10/2023]
Abstract
The ability of satellites to assess surface water quality indicators such as colored dissolved organic matter (CDOM) suggests that remote sensing could be a useful tool for evaluating water treatability metrics in considering potential drinking water supplies. To explore this possibility, 24 surface water samples were collected throughout Minnesota, USA with wide ranging values of CDOM (a440; 0.41-27.9 m-1), dissolved organic carbon (DOC; 5.5-47.6 mg/L) and specific ultraviolet absorbance at 254 nm (SUVA254; 1.3-5.1 L/mg-M). Laboratory experiments were performed to quantify chlorine demand and the formation of two classes of halogenated disinfection byproducts (DBPs), trihalomethanes (THMs) and haloacetic acids (HAAs), using the uniform formation conditions (UFC) test. Chlorine demand and THMUFC were linearly correlated with CDOM (R2 = 0.97 and 0.91, respectively), indicating that CDOM is a useful predictor of these parameters. On the other hand, data comparing di- and tri-HAAUFC with CDOM were better fit by a logarithmic relationship (R2 = 0.73 and 0.87, respectively), while mono-HAAUFC was linearly correlated with CDOM (R2 = 0.46) but only for low-to moderately-colored waters (a440 ≤ 11 m-1). The correlations relating chlorine demand and DBPUFC values with CDOM were coupled with satellite CDOM assessments to estimate chlorine demand and DBPUFC values for all surface waters larger than 0.05 km2 in the state of Minnesota, USA. The resulting maps suggest that only 21.8% of Minnesota lakes would meet both the THM and HAA maximum contaminant levels, but only when pre-disinfection treatment removes 75% of DBP precursors. There are limitations to determining CDOM using satellites for high color surface waters (a440 > 11 m-1), however, leading to underpredicted values for CDOM, chlorine demand, and DBPUFC. Overall, the results demonstrate the potential benefits of satellite remote sensing for assessing potential drinking water sources and water treatability metrics.
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Affiliation(s)
- Yiling Chen
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, MN, 55455-0116, United States
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, MN, 55455-0116, United States
| | - Claire G Griffin
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, St. Paul, MN, 55108-6097, United States
| | - Leif G Olmanson
- Department of Forest Resources, University of Minnesota, 1530 Cleveland Avenue North, St. Paul, MN, 55108-6112, United States
| | - Patrick L Brezonik
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, MN, 55455-0116, United States
| | - Raymond M Hozalski
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, MN, 55455-0116, United States.
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Schendorf TM, Del Vecchio R, Bianca M, Blough NV. Combined Effects of pH and Borohydride Reduction on Optical Properties of Humic Substances (HS): A Comparison of Optical Models. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6310-6319. [PMID: 31063364 DOI: 10.1021/acs.est.9b01516] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The combined effects of pH and borohydride reduction on the optical properties of a series of humic substances and a lignin model were examined to probe the molecular moieties and interactions that give rise to the observed optical properties of these materials. Increasing the pH from 2 to 12 produced significantly enhanced absorption across the spectra of all samples, with distinct spectral responses observed over pH ranges attributable to the deprotonation of carboxylic acids and phenols. Borohydride reduction substantially attenuated the broadband absorption enhancements with pH, clearly indicating that the loss of absorption due to ketone/aldehyde reduction is coupled with the pH-dependent increase in absorption due to deprotonation of carboxylic acids and phenols. These results cannot be easily explained by a superposition of the spectra of independently absorbing chromophores (superposition model) but are readily interpretable within a charge transfer (CT) model. Changes of fluorescence emission with pH for both untreated and borohydride reduced samples suggest that a pH-dependent structural reorganization of the HS may also be influencing the fluorescence emission. Independent of optical model, these results demonstrate that chemical tests targeted to specific moieties can identify distinct structural differences among HS sources as well as provide insight into the molecular moieties and interactions that produce the observed optical and photochemical properties.
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16
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Tian CB, Li YY, Wang X, Fan WH, Wang G, Liang JY, Wang ZY, Liu H. Effects of UV-B radiation on the survival, egg hatchability and transcript expression of antioxidant enzymes in a high-temperature adapted strain of Neoseiulus barkeri. EXPERIMENTAL & APPLIED ACAROLOGY 2019; 77:527-543. [PMID: 31062204 DOI: 10.1007/s10493-019-00361-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 04/17/2019] [Indexed: 05/19/2023]
Abstract
Biological control of spider mites in hot and dry weather is a serious technical issue. A high-temperature adapted strain (HTAS) of the predatory mite Neoseiulus barkeri Hughes was selected from its conventional strain (CS), via long-term heat acclimation and frequent heat hardenings in our previous studies. However, the environment of high temperature is usually associated with enhanced ultraviolet (UV) radiation. In the present study, the physiological effects of UV-B radiation on survival rate and egg damage of N. barkeri were investigated, as well as the activities and expression profiles of antioxidant enzymes to UV-B radiation stress. UV-B radiation had deleterious effects on egg hatchability and survival of N. barkeri. Adults of the HTAS strain were less UV-B resistant than those of the CS strain; they also had lower levels of enzymatic activity of superoxide dismutase (SOD) and catalase against oxidative damage and weaker upregulation of SOD genes. The mRNA expression of three SOD genes of CS adult females immediately increased whereas that of HTAS showed almost no difference under UV-B stress for 1 h. The results showed the HTAS of N. barkeri had lower fitness under UV-B stress compared with the CS of N. barkeri. These results suggested that long-term heat acclimation may exert a profound impact on the developmental physiology of N. barkeri.
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Affiliation(s)
- Chuan-Bei Tian
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Ya-Ying Li
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Xian Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Wen-Hui Fan
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Ge Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Jing-Yu Liang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Zi-Ying Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Huai Liu
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, China.
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Lamy K, Portafaix T, Josse B, Brogniez C, Godin-Beekmann S, Bencherif H, Revell L, Akiyoshi H, Bekki S, Hegglin MI, Jöckel P, Kirner O, Marecal V, Morgenstern O, Stenke A, Zeng G, Abraham NL, Archibald AT, Butchart N, Chipperfield MP, Di Genova G, Deushi M, Dhomse SS, Hu RM, Kinnison D, Michou M, O'Connor FM, Oman LD, Pitari G, Plummer DA, Pyle JA, Rozanov E, Saint-Martin D, Sudo K, Tanaka TY, Visioni D, Yoshida K. Ultraviolet radiation modelling using output from the Chemistry Climate Model Initiative. ATMOSPHERIC CHEMISTRY AND PHYSICS DISCUSSIONS : ACPD 2019; 19:10087-10110. [PMID: 31632450 PMCID: PMC6800685 DOI: 10.5194/acp-2018-525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have derived values of the Ultraviolet Index (UVI) at solar noon using the Tropospheric Ultraviolet Model (TUV) driven by ozone, temperature and aerosol fields from climate simulations of the first phase of the Chemistry-Climate Model Initiative (CCMI-1). Since clouds remain one of the largest uncertainties in climate projections, we simulated only the clear-sky UVI. We compared the modelled UVI climatologies against present-day climatological values of UVI derived from both satellite data (the OMI-Aura OMUVBd product) and ground-based measurements (from the NDACC network). Depending on the region, relative differences between the UVI obtained from CCMI/TUV calculations and the ground-based measurements ranged between -5.9% and 10.6%. We then calculated the UVI evolution throughout the 21st century for the four Representative Concentration Pathways (RCPs 2.6, 4.5, 6.0 and 8.5). Compared to 1960s values, we found an average increase in the UVI in 2100 (of 2-4%) in the tropical belt (30°N-30°S). For the mid-latitudes, we observed a 1.8 to 3.4 % increase in the Southern Hemisphere for RCP 2.6, 4.5 and 6.0, and found a 2.3% decrease in RCP 8.5. Higher increases in UVI are projected in the Northern Hemisphere except for RCP 8.5. At high latitudes, ozone recovery is well identified and induces a complete return of mean UVI levels to 1960 values for RCP 8.5 in the Southern Hemisphere. In the Northern Hemisphere, UVI levels in 2100 are higher by 0.5 to 5.5% for RCP 2.6, 4.5 and 6.0 and they are lower by 7.9% for RCP 8.5. We analysed the impacts of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) on UVI from 1960 by comparing CCMI sensitivity simulations (1960-2100) with fixed GHGs or ODSs at their respective 1960 levels. As expected with ODS fixed at their 1960 levels, there is no large decrease in ozone levels and consequently no sudden increase in UVI levels. With fixed GHG, we observed a delayed return of ozone to 1960 values, with a corresponding pattern of change observed on UVI, and looking at the UVI difference between 2090s values and 1960s values, we found an 8 % increase in the tropical belt during the summer of each hemisphere. Finally we show that, while in the Southern Hemisphere the UVI is mainly driven by total ozone column, in the Northern Hemisphere both total ozone column and aerosol optical depth drive UVI levels, with aerosol optical depth having twice as much influence on the UVI as total ozone column does.
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Affiliation(s)
- Kévin Lamy
- LACy, Laboratoire de l'Atmosphère et des Cyclones (UMR 8105 CNRS, Université de La Réunion, Météo-France), Saint-Denis de La Réunion, France
| | - Thierry Portafaix
- LACy, Laboratoire de l'Atmosphère et des Cyclones (UMR 8105 CNRS, Université de La Réunion, Météo-France), Saint-Denis de La Réunion, France
| | - Béatrice Josse
- Centre National de Recherches Météorologiques (CNRM) UMR 3589, Météo-France/CNRS, Toulouse, France
| | - Colette Brogniez
- Laboratoire d'Optique Atmosphérique (LOA), Université de Lille, Faculté des Sciences et Technologies, Villeneuve d'Ascq, France
| | - Sophie Godin-Beekmann
- Laboratoire Atmosphères, Milieux, Observations Spatiales, Service d'Aéronomie (LATMOS), CNRS, Institut Pierre Simon Laplace, Pierre et Marie Curie University, Paris, France
| | - Hassan Bencherif
- LACy, Laboratoire de l'Atmosphère et des Cyclones (UMR 8105 CNRS, Université de La Réunion, Météo-France), Saint-Denis de La Réunion, France
- School of Chemistry and Physics, University of KwaZulu Natal, Durban, South Africa
| | - Laura Revell
- Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland
- Bodeker Scientific, Christchurch, New Zealand
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Slimane Bekki
- Laboratoire Atmosphères, Milieux, Observations Spatiales, Service d'Aéronomie (LATMOS), CNRS, Institut Pierre Simon Laplace, Pierre et Marie Curie University, Paris, France
| | | | - Patrick Jöckel
- Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany
| | - Oliver Kirner
- Steinbuch Centre for Computing, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Virginie Marecal
- Centre National de Recherches Météorologiques (CNRM) UMR 3589, Météo-France/CNRS, Toulouse, France
| | - Olaf Morgenstern
- National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand
| | - Andrea Stenke
- Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland
| | - Guang Zeng
- National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand
| | - N Luke Abraham
- Department of Chemistry, University of Cambridge, Cambridge, UK
- National Centre for Atmospheric Science, U.K
| | | | | | | | - Glauco Di Genova
- Department of Physical and Chemical Sciences, Universitá dell'Aquila, L'Aquila, Italy
| | - Makoto Deushi
- Meteorological Research Institute (MRI), Tsukuba, Japan
| | - Sandip S Dhomse
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Rong-Ming Hu
- Laboratoire Atmosphères, Milieux, Observations Spatiales, Service d'Aéronomie (LATMOS), CNRS, Institut Pierre Simon Laplace, Pierre et Marie Curie University, Paris, France
| | - Douglas Kinnison
- National Center for Atmospheric Research (NCAR), Boulder, Colorado, USA
| | - Martine Michou
- Centre National de Recherches Météorologiques (CNRM) UMR 3589, Météo-France/CNRS, Toulouse, France
| | | | - Luke D Oman
- National Aeronautics and Space Administration Goddard Space Flight Center (NASA GSFC), Greenbelt, Maryland, USA
| | - Giovanni Pitari
- Department of Physical and Chemical Sciences, Universitá dell'Aquila, L'Aquila, Italy
| | | | - John A Pyle
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Eugene Rozanov
- Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland
- Physikalisch-Meteorologisches Observatorium Davos World Radiation Centre, Davos Dorf, Switzerland
| | - David Saint-Martin
- Centre National de Recherches Météorologiques (CNRM) UMR 3589, Météo-France/CNRS, Toulouse, France
| | - Kengo Sudo
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | | | - Daniele Visioni
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - Kohei Yoshida
- Meteorological Research Institute (MRI), Tsukuba, Japan
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18
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Combined Effects of Trace Metals and Light on Photosynthetic Microorganisms in Aquatic Environment. ENVIRONMENTS 2018. [DOI: 10.3390/environments5070081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the present review, we critically examine the state-of-the-art of the research on combined effects of trace metals and light on photosynthetic microorganisms in aquatic environment. Light of different intensity and spectral composition affects the interactions between trace metals and photosynthetic microorganisms directly, by affecting vital cellular functions and metal toxicokinetics and toxicodynamics, and indirectly, by changing ambient medium characteristics. Light radiation and in particular, the ultraviolet radiation component (UVR) alters the structure and reactivity of dissolved organic matter in natural water, which in most of the cases decreases its metal binding capacity and enhances metal bioavailability. The increase of cellular metal concentrations is generally associated with increasing light intensity, however further studies are necessary to better understand the underlying mechanisms. Studies on the combined exposures of photosynthetic microorganisms to metals and UVR reveal antagonistic, additive or synergistic interactions depending on light intensity, spectral composition or light pre-exposure history. Among the light spectrum components, most of the research was performed with UVR, while the knowledge on the role of high-intensity visible light and environmentally relevant solar light radiation is still limited. The extent of combined effects also depends on the exposure sequence and duration, as well as the species-specific sensitivity of the tested microorganisms and the activation of stress defense responses.
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Kim J, Cho HM, Kim G. Significant production of humic fluorescent dissolved organic matter in the continental shelf waters of the northwestern Pacific Ocean. Sci Rep 2018; 8:4887. [PMID: 29559703 PMCID: PMC5861113 DOI: 10.1038/s41598-018-23299-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/08/2018] [Indexed: 11/09/2022] Open
Abstract
Fluorescent dissolved organic matter (FDOM) is important for marine organisms and the global carbon cycle contributing to the optical properties of surface seawater and organic carbon budgets. Rivers are known to be the main source of FDOM in coastal oceans and marginal seas. In this study, however, we show that the contribution of FDOM produced from organic sediments of the northwestern Pacific continental shelf is similar to that from the Changjiang River. FDOM showed relatively higher concentrations at stations off the Changjiang River mouth and in the central Yellow Sea. Based on temperature-salinity diagrams, the major source of surface FDOM in summer surface waters was found to be from the Changjiang River while that observed in the winter water column was produced mainly in the continental shelf. A good correlation between 228Ra and the humic-like FDOM (FDOMH) during the winter suggests that the FDOMH is produced mainly from marine sediments and enriched in water over the water residence times. A simple mass balance calculation shows that the excess FDOMH fluxes produced from marine sediments account for 30–40% of the riverine source. This result suggests that the continental shelf is an important hidden source of FDOM in the upper ocean.
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Affiliation(s)
- Jeonghyun Kim
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Hyung-Mi Cho
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Guebuem Kim
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea.
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20
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Phytoplankton as Key Mediators of the Biological Carbon Pump: Their Responses to a Changing Climate. SUSTAINABILITY 2018. [DOI: 10.3390/su10030869] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The world’s oceans are a major sink for atmospheric carbon dioxide (CO2). The biological carbon pump plays a vital role in the net transfer of CO2 from the atmosphere to the oceans and then to the sediments, subsequently maintaining atmospheric CO2 at significantly lower levels than would be the case if it did not exist. The efficiency of the biological pump is a function of phytoplankton physiology and community structure, which are in turn governed by the physical and chemical conditions of the ocean. However, only a few studies have focused on the importance of phytoplankton community structure to the biological pump. Because global change is expected to influence carbon and nutrient availability, temperature and light (via stratification), an improved understanding of how phytoplankton community size structure will respond in the future is required to gain insight into the biological pump and the ability of the ocean to act as a long-term sink for atmospheric CO2. This review article aims to explore the potential impacts of predicted changes in global temperature and the carbonate system on phytoplankton cell size, species and elemental composition, so as to shed light on the ability of the biological pump to sequester carbon in the future ocean.
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21
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Planetary boundaries for a blue planet. Nat Ecol Evol 2017; 1:1625-1634. [DOI: 10.1038/s41559-017-0319-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/16/2017] [Indexed: 11/08/2022]
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Awad J, van Leeuwen J, Chow CWK, Smernik RJ, Anderson SJ, Cox JW. Seasonal variation in the nature of DOM in a river and drinking water reservoir of a closed catchment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 220:788-796. [PMID: 27823862 DOI: 10.1016/j.envpol.2016.10.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/12/2016] [Accepted: 10/18/2016] [Indexed: 06/06/2023]
Abstract
Dissolved organic matter (DOM) in surface waters used for drinking purposes can vary markedly in character depending on its source within catchments and the timing and intensity of rainfall events. Here we report the findings of a study on the character and concentration of DOM in waters collected during different seasons from Myponga River and Reservoir, South Australia. The character of DOM was assessed in terms of its treatability by enhanced coagulation and potential for disinfection by-product i.e. trihalomethane (THM) formation. During the wet seasons (winter and spring), water samples from the river had higher DOC concentrations (X¯: 21 mg/L) and DOM of higher average molecular weight (AMW: 1526 Da) than waters collected during the dry seasons (summer and autumn: DOC: 13 mg/L; AMW: 1385 Da). Even though these features led to an increase in the percentage removal of organics by coagulation with alum (64% for wet compared with 53% for dry season samples) and a lower alum dose rate (10 versus 15 mg alum/mg DOC removal), there was a higher THM formation potential (THMFP) from wet season waters (treated waters: 217 μg/L vs 172 μg/L). For reservoir waters, samples collected during the wet seasons had an average DOC concentration (X¯: 15 mg/L), percentage removal of organics by alum (54%), alum dose rates (13 mg/mg DOC) and THMFP (treated waters: 207 μg/L) that were similar to samples collected during the dry seasons (mean DOC: 15 mg/L; removal of organics: 52%; alum dose rate: 13 mg/mg DOC; THMFP: 212 μg/L for treated waters). These results show that DOM present in river waters and treatability by alum are highly impacted by seasonal environmental variations. However these in reservoir waters exhibit less seasonal variability. Storage of large volumes of water in the reservoir enables mixing of influent waters and stabilization of water quality.
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Affiliation(s)
- John Awad
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia
| | - John van Leeuwen
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia; SKLEAC, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China.
| | - Christopher W K Chow
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia; Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, South Australia, 5000, Australia; SKLEAC, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China
| | - Ronald J Smernik
- School of Agriculture, Food & Wine and Waite Research Institute, The University of Adelaide, Urrbrae, South Australia, 5064, Australia
| | - Sharolyn J Anderson
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia
| | - Jim W Cox
- School of Biological Sciences, The University of Adelaide, North Terrace, South Australia, 5005, Australia; South Australian Research and Development Institute, Urrbrae, South Australia, 5064, Australia
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Cuss CW, McConnell SM, Guéguen C. Combining parallel factor analysis and machine learning for the classification of dissolved organic matter according to source using fluorescence signatures. CHEMOSPHERE 2016; 155:283-291. [PMID: 27131448 DOI: 10.1016/j.chemosphere.2016.04.061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/17/2016] [Accepted: 04/18/2016] [Indexed: 05/27/2023]
Abstract
Parallel factor (PARAFAC) analysis of dissolved organic matter (DOM) fluorescence has facilitated a surge of investigation into its biogeochemical cycling. However, rigorous, PARAFAC-based methods for holistically distinguishing DOM sources are lacking. This study classified 1029 PARAFAC-analyzed excitation-emission matrices (EEMs) measured using DOM isolated from 24 different leaf leachates, rivers, and organic matter standards using four machine learning methods (MLM). EEMs were also divided into subsets to assess the impact of experimental treatments (i.e. whole EEMs, size fractionation, mixtures, quenching) and dataset properties (i.e. different numbers of EEMs from each leachate/river) on classification. A split-half validated, 10-component PARAFAC model was extended to 12 components to remove consistent peaks evident in model residuals. The 12-component model performed better than the 10-component model, correctly classifying up to 80 additional EEMs, when the dataset included size-fractionated DOM or several different sources (i.e. many leaf species and rivers); however, the 10-component model performed better for whole-sample EEMs when comparing leaf leachates to rivers. The MLM correctly classified whole EEMs of riverine DOM by source with up to 87.0% accuracy, leachates with up to 92.5% accuracy, and distinguished leachates from rivers with 97.2% accuracy. A difference of up to 17.3% in classification accuracy was observed depending on the MLM method used with the following order: multilayer perceptron = support vector machine > k-nearest neighbours ≫ decision tree; however, performances differed widely depending on the data subset. Classification accuracy for whole and size-fractionated rivers compared to whole and size-fractionated leachates using N-way partial least-squares discriminant analysis (NPLS-DA; 97.7%) was similar to that achieved using MLM. Combining MLM with PARAFAC is an effective method for classifying DOM based on its fluorescence signature because PARAFAC can isolate meaningful fluorescent species and unlike PLSDA, MLM constructs a single model which simultaneously classifies EEMs as belonging to one of several categories. A complete accounting of carbon flows through ecosystems should include the processes and sources that contribute to the disparate fluorescence signatures of riverine and leached DOM.
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Affiliation(s)
- C W Cuss
- Environmental and Life Sciences Graduate Program, Trent University, ON, Canada.
| | - S M McConnell
- Department of Computing and Information Systems, Trent University, ON, Canada
| | - C Guéguen
- Chemistry Department, Trent University, ON, Canada.
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Moslehyani A, Mobaraki M, Isloor A, Ismail A, Othman M. Photoreactor-ultrafiltration hybrid system for oily bilge water photooxidation and separation from oil tanker. REACT FUNCT POLYM 2016. [DOI: 10.1016/j.reactfunctpolym.2016.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cuss CW, Guéguen C, Andersson P, Porcelli D, Maximov T, Kutscher L. Advanced Residuals Analysis for Determining the Number of PARAFAC Components in Dissolved Organic Matter. APPLIED SPECTROSCOPY 2016; 70:334-346. [PMID: 26783366 DOI: 10.1177/0003702815620546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 07/02/2015] [Indexed: 06/05/2023]
Abstract
Parallel factor analysis (PARAFAC) has facilitated an explosion in research connecting the fluorescence properties of dissolved organic matter (DOM) to its functions and biogeochemical cycling in natural and engineered systems. However, the validation of robust PARAFAC models using split-half analysis requires an oft unrealistically large number (hundreds to thousands) of excitation-emission matrices (EEMs), and models with too few components may not adequately describe differences between DOM. This study used self-organizing maps (SOM) and comparing changes in residuals with the effects of adding components to estimate the number of PARAFAC components in DOM from two data sets: MS (110 EEMs from nine leaf leachates and headwaters) and LR (64 EEMs from the Lena River). Clustering by SOM demonstrated that peaks clearly persisted in model residuals after validation by split-half analysis. Plotting the changes to residuals was an effective method for visualizing the removal of fluorophore-like fluorescence caused by increasing the number of PARAFAC components. Extracting additional PARAFAC components via residuals analysis increased the proportion of correctly identified size-fractionated leaf leachates from 56.0 ± 0.8 to 75.2 ± 0.9%, and from 51.7 ± 1.4 to 92.9 ± 0.0% for whole leachates. Model overfitting was assessed by considering the correlations between components, and their distributions amongst samples. Advanced residuals analysis improved the ability of PARAFAC to resolve the variation in DOM fluorescence, and presents an enhanced validation approach for assessing the number of components that can be used to supplement the potentially misleading results of split-half analysis.
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Affiliation(s)
- Chad W Cuss
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Céline Guéguen
- Department of Chemistry, Trent University, Peterborough, ON, Canada
| | - Per Andersson
- Swedish Museum of Natural History, Department of Geoscience, Stockholm, Sweden
| | - Don Porcelli
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Trofim Maximov
- International Center for BioGeoScience Educational and Scientific Training (BEST) of North-Eastern Federal University, Yakutsk, Republic of Sakha (Yakutia), Russia
| | - Liselott Kutscher
- Swedish Museum of Natural History, Department of Geoscience, Stockholm, Sweden
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Inhibition of the RhoA GTPase Activity Increases Sensitivity of Melanoma Cells to UV Radiation Effects. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:2696952. [PMID: 26823948 PMCID: PMC4707346 DOI: 10.1155/2016/2696952] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/25/2015] [Indexed: 01/16/2023]
Abstract
Ultraviolet radiation is the main cause of DNA damage to melanocytes and development of melanoma, one of the most lethal human cancers, which leads to metastasis due to uncontrolled cell proliferation and migration. These phenotypes are mediated by RhoA, a GTPase overexpressed or overactivated in highly aggressive metastatic tumors that plays regulatory roles in cell cycle progression and cytoskeleton remodeling. This work explores whether the effects of UV on DNA damage, motility, proliferation, and survival of human metastatic melanoma cells are mediated by the RhoA pathway. Mutant cells expressing dominant-negative (MeWo-RhoA-N19) or constitutively active RhoA (MeWo-RhoA-V14) were generated and subjected to UV radiation. A slight reduction in migration and invasion was observed in MeWo and MeWo-RhoA-V14 cells but not in MeWo-RhoA-N19 cells, which presented inefficient motility and invasiveness associated with stress fibers fragmentation. Proliferation and survival of RhoA-deficient cells were drastically reduced by UV compared to cells displaying normal or high RhoA activity, suggesting increased sensitivity to UV. Loss of RhoA activity also caused less efficient DNA repair, with elevated levels of DNA lesions such as strand breaks and cyclobutane pyrimidine dimers (CPDs). Thus, RhoA mediates genomic stability and represents a potential target for sensitizing metastatic tumors to genotoxic agents.
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García-Gómez C, Gordillo FJL, Palma A, Lorenzo MR, Segovia M. Elevated CO2 alleviates high PAR and UV stress in the unicellular chlorophyte Dunaliella tertiolecta. Photochem Photobiol Sci 2015; 13:1347-58. [PMID: 25043601 DOI: 10.1039/c4pp00044g] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects of increased CO2 and irradiance on the physiological performance of the chlorophyte Dunaliella tertiolecta were studied at different PAR and UVR (UVA + UVB) irradiances, simulating the solar radiation at different depths, at present (390 ppmv, LC) and predicted CO2 levels for the year 2100 (1000 ppmv, HC). Elevated CO2 resulted in higher optimum and effective quantum yields (F(v)/F(m) and ϕPSII, respectively), electron transport rates (ETR) and specific growth rates (μ). Cell stress was alleviated in HC with respect to LC as evidenced by a decrease in reactive oxygen species (ROS) accumulation. DNA damage showed a 42-fold increase in cyclobutane-pyrimidine dimer (CPD) formation under the highest irradiance (1100 μmol quanta m(-2) s(-1)) in LC with respect to the lowest irradiance (200 μmol quanta m(-2) s(-1)). Photolyase (CII-PCD-PL) gene expression was upregulated under HC resulting in a drastic decrease in CPD accumulation to only 25% with respect to LC. Proliferating cell nuclear antigen (PCNA) accumulation was always higher in HC and the accumulation pattern indicated its involvement in repair or growth depending on the irradiance dose. The repressor of silencing (ROS1) was only marginally involved in the response, suggesting that photoreactivation was the most relevant mechanism to overcome UVR damage. Our results demonstrate that future scenarios of global change result in alleviation of irradiance stress by CO2-induced photoprotection in D. tertiolecta.
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Affiliation(s)
- Candela García-Gómez
- Department of Ecology, Faculty of Sciences, University of Málaga, Bvd. Louis Pasteur s/n, 29010 Málaga, Spain.
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Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact. Sci Rep 2015; 5:14851. [PMID: 26423726 PMCID: PMC4589766 DOI: 10.1038/srep14851] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 08/24/2015] [Indexed: 11/23/2022] Open
Abstract
The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14–19% and the ambient radiation by 9–16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems.
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Pan X, Song YB, Liu GF, Hu YK, Ye XH, Cornwell WK, Prinzing A, Dong M, Cornelissen JH. Functional traits drive the contribution of solar radiation to leaf litter decomposition among multiple arid-zone species. Sci Rep 2015; 5:13217. [PMID: 26282711 PMCID: PMC4539537 DOI: 10.1038/srep13217] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 07/21/2015] [Indexed: 11/09/2022] Open
Abstract
In arid zones, strong solar radiation has important consequences for ecosystem processes. To better understand carbon and nutrient dynamics, it is important to know the contribution of solar radiation to leaf litter decomposition of different arid-zone species. Here we investigated: (1) whether such contribution varies among plant species at given irradiance regime, (2) whether interspecific variation in such contribution correlates with interspecific variation in the decomposition rate under shade; and (3) whether this correlation can be explained by leaf traits. We conducted a factorial experiment to determine the effects of solar radiation and environmental moisture for the mass loss and the decomposition constant k-values of 13 species litters collected in Northern China. The contribution of solar radiation to leaf litter decomposition varied significantly among species. Solar radiation accelerated decomposition in particular in the species that already decompose quickly under shade. Functional traits, notably specific leaf area, might predict the interspecific variation in that contribution. Our results provide the first empirical evidence for how the effect of solar radiation on decomposition varies among multiple species. Thus, the effect of solar radiation on the carbon flux between biosphere and atmosphere may depend on the species composition of the vegetation.
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Affiliation(s)
- Xu Pan
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yao-Bin Song
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Guo-Fang Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yu-Kun Hu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xue-Hua Ye
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - William K. Cornwell
- Department of Ecological Science, VU University, Amsterdam, the Netherlands
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Andreas Prinzing
- Université de Rennes 1, Centre National de la Recherche Scientifique, Rennes, France
| | - Ming Dong
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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Valencia-Gómez E, Maestre FT, Le Bagousse-Pinguet Y, Quero JL, Tamme R, Börger L, García-Gómez M, Gross N. Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands. THE NEW PHYTOLOGIST 2015; 206:660-71. [PMID: 25615801 PMCID: PMC4407978 DOI: 10.1111/nph.13268] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/02/2014] [Indexed: 05/17/2023]
Abstract
We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity (FD) and community-weighted mean trait values (CWM)), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e. the provision of several ecosystem functions simultaneously). Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or nonsprouting shrub species considered. FD and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g. vegetative height or lateral spread) and leaf traits (e.g. specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r(2) = 0.63). FD also improved the resistance of multifunctionality along the aridity gradient studied. Maintaining and enhancing FD in plant communities may help to buffer negative effects of ongoing global environmental change on dryland multifunctionality.
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Affiliation(s)
- Enrique Valencia-Gómez
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Spain
- Corresponding author: Enrique Valencia Gómez: Tel: +34 914888517
| | - Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Spain
| | - Yoann Le Bagousse-Pinguet
- Department of Botany, Faculty of Science; University of South Bohemia, Branisovska 31, CZ-370 05 Ceske Budejovice, Czech Republic
| | - José Luis Quero
- Departamento de Ingeniería Forestal Escuela Técnica Superior de Ingeniería Agronómica y de Montes Universidad de Córdoba Campus de Rabanales Crta. N-IV km. 396 C.P. 14071, Córdoba, Spain
| | - Riin Tamme
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu, Estonia
| | - Luca Börger
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Miguel García-Gómez
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Spain
- Departamento de Ingeniería y Morfología del Terreno, Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Calle Profesor Aranguren s/n, 28040 Madrid, Spain
| | - Nicolas Gross
- INRA, USC1339 Chizé (CEBC), F-79360, Villiers en Bois, France
- Centre d’étude biologique de Chizé, CNRS - Université La Rochelle (UMR 7372), F-79360, Villiers en Bois, France
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Distinctive anthocyanin accumulation responses to temperature and natural UV radiation of two field-grown (Vitis vinifera L.) cultivars. Molecules 2015; 20:2061-80. [PMID: 25633334 PMCID: PMC6272526 DOI: 10.3390/molecules20022061] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/20/2015] [Indexed: 01/04/2023] Open
Abstract
The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (>35 °C) and low (<15 °C and <17 °C) temperatures during ripening.
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Schmidt ÉC, Kreusch M, Felix MRDL, Pereira DT, Costa GB, Simioni C, Ouriques LC, Farias-Soares FL, Steiner N, Chow F, Ramlov F, Maraschin M, Bouzon ZL. Effects of Ultraviolet Radiation (UVA+UVB) and Copper on the Morphology, Ultrastructural Organization and Physiological Responses of the Red AlgaPterocladiella capillacea. Photochem Photobiol 2015; 91:359-70. [DOI: 10.1111/php.12396] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 11/18/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Éder C. Schmidt
- Postdoctoral Research of Postgraduate Program in Cell Biology and Development; Department of Cell Biology, Embryology and Genetics; Federal University of Santa Catarina; Florianópolis SC Brazil
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Marianne Kreusch
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Marthiellen R. de L. Felix
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Debora T. Pereira
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Giulia B. Costa
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Carmen Simioni
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Luciane C. Ouriques
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | | | - Neusa Steiner
- Department of Botany; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Fungyi Chow
- Department of Botany; Institute of Bioscience; University of São Paulo; São Paulo SP Brazil
| | - Fernanda Ramlov
- Plant Morphogenesis and Biochemistry Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Marcelo Maraschin
- Plant Morphogenesis and Biochemistry Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
| | - Zenilda L. Bouzon
- Department of Cell Biology, Embryology and Genetics; Plant Cell Biology Laboratory; Federal University of Santa Catarina; Florianópolis SC Brazil
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Six LJ, Bakker JD, Bilby RE. Vegetation dynamics in a novel ecosystem: agroforestry effects on grassland vegetation in Uruguay. Ecosphere 2014. [DOI: 10.1890/es13-00347.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Sharpless CM, Blough NV. The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:654-71. [PMID: 24509887 DOI: 10.1039/c3em00573a] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Absorption of sunlight by chromophoric dissolved natural organic matter (CDOM) is environmentally significant because it controls photic zone depth and causes photochemistry that affects elemental cycling and contaminant fate. Both the optics (absorbance and fluorescence) and photochemistry of CDOM display unusual properties that cannot easily be ascribed to a superposition of individual chromophores. These include (i) broad, unstructured absorbance that decreases monotonically well into the visible and near IR, (ii) fluorescence emission spectra that all fall into a single envelope regardless of the excitation wavelength, and (iii) photobleaching and photochemical quantum yields that decrease monotonically with increasing wavelength. In contrast to a simple superposition model, these phenomena and others can be reasonably well explained by a physical model in which charge-transfer interactions between electron donating and accepting chromophores within the CDOM control the optical and photophysical properties. This review summarizes current understanding of the processes underlying CDOM photophysics and photochemistry as well as their physical basis.
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Affiliation(s)
- Charles M Sharpless
- Department of Chemistry, University of Mary Washington, Fredericksburg, VA 22401, USA.
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Loayza-Muro RA, Duivenvoorden JF, Kraak MHS, Admiraal W. Metal leaching, acidity, and altitude confine benthic macroinvertebrate community composition in Andean streams. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:404-411. [PMID: 24150981 DOI: 10.1002/etc.2436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/05/2013] [Accepted: 10/15/2013] [Indexed: 06/02/2023]
Abstract
Andean streams drain metal-rich bedrock and are subjected to an extreme altitude gradient, which may create highly selective conditions for life. The aim of the present study was to evaluate the combined effects of metals and altitude on benthic macroinvertebrate community composition in Andean streams. Metal-rich sites were characterized by high metal concentrations and low pH, and high-altitude sites were characterized by high ultraviolet-B radiation and low concentrations of dissolved organic matter. Canonical correspondence analysis indicated that the patterns in faunal composition were best explained by metals followed by altitude, with dipterans and collembolans occurring mostly under harsh conditions of high altitude and high metal levels. Interaction between metals and altitude was most evident at metal-rich sites. It is suggested that in Andean streams, metal leaching from igneous rock and altitude may be important factors confining benthic macroinvertebrate communities, reducing their numbers and changing their composition toward specialized taxa.
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Affiliation(s)
- Raúl A Loayza-Muro
- Laboratory of Ecotoxicology, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru; Institute for Biodiversity and Ecosystem Dynamics, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
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Kitzing C, Pröschold T, Karsten U. UV-induced effects on growth, photosynthetic performance and sunscreen contents in different populations of the green alga Klebsormidium fluitans (Streptophyta) from alpine soil crusts. MICROBIAL ECOLOGY 2014; 67:327-40. [PMID: 24233286 DOI: 10.1007/s00248-013-0317-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 10/16/2013] [Indexed: 05/22/2023]
Abstract
Members of the green algal genus Klebsormidium (Klebsormidiales, Streptophyta) are typical components of biological soil crust communities worldwide, which exert important ecological functions. Klebsormidium fluitans (F. Gay) Lokhorst was isolated from an aeroterrestrial biofilm as well as from four different biological soil crusts along an elevational gradient between 600 and 2350 m in the Tyrolean and South Tyrolean Alps (Austria, Italy), which are characterised by seasonally high solar radiation. Since the UVtolerance of Klebsormidium has not been studied in detail, an ecophysiological and biochemical study was applied. The effects of controlled artificial ultraviolet radiation (UVR; <9 W m(-2) UV-A, <0.5 W m(-2) UV-B) on growth, photosynthetic performance and the capability to synthesise mycosporine-like amino acids (MAAs) as potential sunscreen compounds were comparatively investigated to evaluate physiological plasticity and possible ecotypic differentiation within this Klebsormidium species. Already under control conditions, the isolates showed significantly different growth rates ranging from 0.42 to 0.74 μm day(-1). The UVR effects on growth were isolate specific, with only two strains affected by the UV treatments. Although all photosynthetic and respiratory data indicated strain-specific differences under control conditions, UV-A and UV-B treatment led only to rather minor effects. All physiological results clearly point to a high UV tolerance in the K. fluitans strains studied, which can be explained by their biochemical capability to synthesize and accumulate a putative MAA after exposure to UV-A and UV-B. Using HPLC, a UV-absorbing compound with an absorption maximum at 324 nm could be identified in all strains. The steady-state concentrations of this Klebsormidium MAA under control conditions ranged from 0.09 to 0.93 mg g(-1) dry weight (DW). While UV-A led to a slight stimulation of MAA accumulation, exposure to UV-B was accompanied by a strong but strain-specific increase of this compound (5.34-12.02 mg(-1) DW), thus supporting its function as UV sunscreen. Although ecotypic differences in the UVR response patterns of the five K. fluitans strains occurred, this did not correlate with the altitude of the respective sampling location. All data indicate a generally high UV tolerance which surely contributes to the aeroterrestrial lifestyle of K. fluitans in soil crusts of the alpine regions of the European Alps.
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39
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Jaggernath J, Haslam D, Naidoo KS. Climate change: Impact of increased ultraviolet radiation and water changes on eye health. Health (London) 2013. [DOI: 10.4236/health.2013.55122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Matallana-Surget S, Villette C, Intertaglia L, Joux F, Bourrain M, Lebaron P. Response to UVB radiation and oxidative stress of marine bacteria isolated from South Pacific Ocean and Mediterranean Sea. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2012; 117:254-61. [DOI: 10.1016/j.jphotobiol.2012.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/17/2012] [Accepted: 09/25/2012] [Indexed: 10/27/2022]
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Nelson NB, Siegel DA. The global distribution and dynamics of chromophoric dissolved organic matter. ANNUAL REVIEW OF MARINE SCIENCE 2012; 5:447-76. [PMID: 22809178 DOI: 10.1146/annurev-marine-120710-100751] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Chromophoric dissolved organic matter (CDOM) is a ubiquitous component of the open ocean dissolved matter pool, and is important owing to its influence on the optical properties of the water column, its role in photochemistry and photobiology, and its utility as a tracer of deep ocean biogeochemical processes and circulation. In this review, we discuss the global distribution and dynamics of CDOM in the ocean, concentrating on developments in the past 10 years and restricting our discussion to open ocean and deep ocean (below the main thermocline) environments. CDOM has been demonstrated to exert primary control on ocean color by its absorption of light energy, which matches or exceeds that of phytoplankton pigments in most cases. This has important implications for assessing the ocean biosphere via ocean color-based remote sensing and the evaluation of ocean photochemical and photobiological processes. The general distribution of CDOM in the global ocean is controlled by a balance between production (primarily microbial remineralization of organic matter) and photolysis, with vertical ventilation circulation playing an important role in transporting CDOM to and from intermediate water masses. Significant decadal-scale fluctuations in the abundance of global surface ocean CDOM have been observed using remote sensing, indicating a potentially important role for CDOM in ocean-climate connections through its impact on photochemistry and photobiology.
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Matallana-Surget S, Joux F, Wattiez R, Lebaron P. Proteome analysis of the UVB-resistant marine bacterium Photobacterium angustum S14. PLoS One 2012; 7:e42299. [PMID: 22870314 PMCID: PMC3411663 DOI: 10.1371/journal.pone.0042299] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 07/03/2012] [Indexed: 12/22/2022] Open
Abstract
The proteome of the marine bacterium Photobacterium angustum S14 was exposed to UVB and analyzed by the implementation of both the post-digest ICPL labeling method and 2D-DIGE technique using exponentially growing cells. A total of 40 and 23 proteins were quantified in all replicates using either the ICPL or 2D-DIGE methods, respectively. By combining both datasets from 8 biological replicates (4 biological replicates for each proteomics technique), 55 proteins were found to respond significantly to UVB radiation in P. angustum. A total of 8 UVB biomarkers of P. angustum were quantified in all replicates using both methods. Among them, the protein found to present the highest increase in abundance (almost a 3-fold change) was RecA, which is known to play a crucial role in the so-called recombinational repair process. We also observed a high number of antioxidants, transport proteins, metabolism-related proteins, transcription/translation regulators, chaperonins and proteases. We also discuss and compare the UVB response and global protein expression profiles obtained for two different marine bacteria with trophic lifestyles: the copiotroph P. angustum and oligotroph Sphingopyxis alaskensis.
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Affiliation(s)
- Sabine Matallana-Surget
- UPMC Univ Paris 06, UMR7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Banyuls/mer, France.
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Paul ND, Moore JP, McPherson M, Lambourne C, Croft P, Heaton JC, Wargent JJ. Ecological responses to UV radiation: interactions between the biological effects of UV on plants and on associated organisms. PHYSIOLOGIA PLANTARUM 2012; 145:565-81. [PMID: 22150399 DOI: 10.1111/j.1399-3054.2011.01553.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Solar ultraviolet (UV)-B radiation (280-315 nm) has a wide range of effects on terrestrial ecosystems, yet our understanding of how UV-B influences the complex interactions of plants with pest, pathogen and related microorganisms remains limited. Here, we report the results of a series of experiments in Lactuca sativa which aimed to characterize not only key plant responses to UV radiation in a field environment but also consequential effects for plant interactions with a sap-feeding insect, two model plant pathogens and phylloplane microorganism populations. Three spectrally modifying filters with contrasting UV transmissions were used to filter ambient sunlight, and when compared with our UV-inclusive filter, L. sativa plants grown in a zero UV-B environment showed significantly increased shoot fresh weight, reduced foliar pigment concentrations and suppressed population growth of green peach aphid (Myzus persicae). Plants grown under a filter which allowed partial transmission of UV-A radiation and negligible UV-B transmission showed increased density of leaf surface phylloplane microbes compared with the UV-inclusive treatment. Effects of UV treatment on the severity of two plant pathogens, Bremia lactucae and Botrytis cinerea, were complex as both the UV-inclusive and zero UV-B filters reduced the severity of pathogen persistence. These results are discussed with reference to known spectral responses of plants, insects and microorganisms, and contrasted with established fundamental responses of plants and other organisms to solar UV radiation, with particular emphasis on the need for future integration between different experimental approaches when investigating the effects of solar UV radiation.
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Affiliation(s)
- Nigel D Paul
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
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Haverstock S, Sizmur T, Murimboh J, O'Driscoll NJ. Modeling the photo-oxidation of dissolved organic matter by ultraviolet radiation in freshwater lakes: implications for mercury bioavailability. CHEMOSPHERE 2012; 88:1220-1226. [PMID: 22521995 DOI: 10.1016/j.chemosphere.2012.03.073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 03/25/2012] [Accepted: 03/27/2012] [Indexed: 05/31/2023]
Abstract
Uncertainties in projected ultraviolet (UV) radiation may lead to future increases in UV irradiation of freshwater lakes. Because dissolved organic carbon (DOC) is the main binding phase for mercury (Hg) in freshwater lakes, an increase in DOC photo-oxidation may affect Hg speciation and bioavailability. We quantified the effect of DOC concentration on the rate of abiotic DOC photo-oxidation for five lakes (DOC=3.27-12.3 mg L(-1)) in Kejimkujik National Park, Canada. Samples were irradiated with UV-A or UV-B radiation over a 72-h period. UV-B radiation was found to be 2.36 times more efficient at photo-oxidizing DOC than UV-A, with energy-normalized rates of dissolved inorganic carbon (DIC) production ranging from 3.8×10(-5) to 1.1×10(-4) mg L(-1)J(-1) for UV-A, and from 6.0×10(-5) to 3.1×10(-4) mg L(-1)J(-1) for UV-B. Energy normalized rates of DIC production were positively correlated with DOC concentrations. Diffuse integrated attenuation coefficients were quantified in situ (UV-A K(d)=0.056-0.180 J cm(-1); UV-B K(d)=0.015-0.165 J cm(-1)) and a quantitative depth-integrated model for yearly DIC photo-production in each lake was developed. The model predicts that, UV-A produces between 3.2 and 100 times more DIC (1521-2851 mg m(-2) year(-1)) than UV-B radiation (29.17-746.7 mg m(-2) year(-1)). Future increases in UV radiation may increase DIC production and increase Hg bioavailability in low DOC lakes to a greater extent than in high DOC lakes.
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Affiliation(s)
- Sarah Haverstock
- Department of Earth & Environmental Science, Acadia University, Wolfville, NS, Canada
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Schuch AP, Yagura T, Makita K, Yamamoto H, Schuch NJ, Agnez-Lima LF, MacMahon RM, Menck CFM. DNA damage profiles induced by sunlight at different latitudes. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:198-206. [PMID: 22674547 DOI: 10.1002/em.21678] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Despite growing knowledge on the biological effects of ultraviolet (UV) radiation on human health and ecosystems, it is still difficult to predict the negative impacts of the increasing incidence of solar UV radiation in a scenario of global warming and climate changes. Hence, the development and application of DNA-based biological sensors to monitor the solar UV radiation under different environmental conditions is of increasing importance. With a mind to rendering a molecular view-point of the genotoxic impact of sunlight, field experiments were undertaken with a DNA-dosimeter system in parallel with physical photometry of solar UVB/UVA radiation, at various latitudes in South America. On applying biochemical and immunological approaches based on specific DNA-repair enzymes and antibodies, for evaluating sunlight-induced DNA damage profiles, it became clear that the genotoxic potential of sunlight does indeed vary according to latitude. Notwithstanding, while induction of oxidized DNA bases is directly dependent on an increase in latitude, the generation of 6-4PPs is inversely so, whereby the latter can be regarded as a biomolecular marker of UVB incidence. This molecular DNA lesion-pattern largely reflects the relative incidence of UVA and UVB energy at any specific latitude. Hereby is demonstrated the applicability of this DNA-based biosensor for additional, continuous field experiments, as a means of registering variations in the genotoxic impact of solar UV radiation.
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Affiliation(s)
- André Passaglia Schuch
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
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George C, D’Anna B, Herrmann H, Weller C, Vaida V, Donaldson DJ, Bartels-Rausch T, Ammann M. Emerging Areas in Atmospheric Photochemistry. Top Curr Chem (Cham) 2012; 339:1-53. [DOI: 10.1007/128_2012_393] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Barnes PW, Throop HL, Hewins DB, Abbene ML, Archer SR. Soil Coverage Reduces Photodegradation and Promotes the Development of Soil-Microbial Films on Dryland Leaf Litter. Ecosystems 2011. [DOI: 10.1007/s10021-011-9511-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Meng X, Zhang Z, Luo N, Cao S, Yang M. Transparent poly(methyl methacrylate)/TiO2 nanocomposites for UV-shielding applications. POLYMER SCIENCE SERIES A 2011. [DOI: 10.1134/s0965545x11100099] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Willis KJ, Feurdean A, Birks HJB, Bjune AE, Breman E, Broekman R, Grytnes JA, New M, Singarayer JS, Rozema J. Quantification of UV-B flux through time using UV-B-absorbing compounds contained in fossil Pinus sporopollenin. THE NEW PHYTOLOGIST 2011; 192:553-560. [PMID: 21810096 DOI: 10.1111/j.1469-8137.2011.03815.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
UV-B radiation currently represents c. 1.5% of incoming solar radiation. However, significant changes are known to have occurred in the amount of incoming radiation both on recent and on geological timescales. Until now it has not been possible to reconstruct a detailed measure of UV-B radiation beyond c. 150 yr ago. Here, we studied the suitability of fossil Pinus spp. pollen to record variations in UV-B flux through time. In view of the large size of the grain and its long fossil history, we hypothesized that this grain could provide a good proxy for recording past variations in UV-B flux. Two key objectives were addressed: to determine whether there was, similar to other studied species, a clear relationship between UV-B-absorbing compounds in the sporopollenin of extant pollen and the magnitude of UV-B radiation to which it had been exposed; and to determine whether these compounds could be extracted from a small enough sample size of fossil pollen to make reconstruction of a continuous record through time a realistic prospect. Preliminary results indicate the excellent potential of this species for providing a quantitative record of UV-B through time. Using this technique, we present the first record of UV-B flux during the last 9500 yr from a site near Bergen, Norway.
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Affiliation(s)
- K J Willis
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
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Magri D. Past UV-B flux from fossil pollen: prospects for climate, environment and evolution. THE NEW PHYTOLOGIST 2011; 192:310-312. [PMID: 21950334 DOI: 10.1111/j.1469-8137.2011.03864.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Donatella Magri
- Dipartimento di Biologia Ambientale, Sapienza University, Roma, Italy.
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