Base de dados : MEDLINE
Pesquisa : G01.311.820.500 [Categoria DeCS]
Referências encontradas : 101 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 11 ir para página                         

  1 / 101 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
[PMID]:29364605
[Au] Autor:Skladnev DA; Mulyukin AL; Filippoval SN; Kulikov EE; Letaroval MA; Yuzbasheva EA; Karnysheva EA; Brushkov AV; Gal'chenko VF
[Ti] Título:[Modeling the Propagation of Microbial Cells and Phage Particles from the Sites of Permafrost Thawing.]
[So] Source:Mikrobiologiia;85(5):580-587, 2016 Sep.
[Is] ISSN:0026-3656
[Cp] País de publicação:Russia (Federation)
[La] Idioma:rus
[Ab] Resumo:A method is proposed for integral assessment of the propagation of microbial cells and viral parti- cles during seasonal thawing of relic ice wedge layers. The results of on-site and laboratory investigation car- ried out in the upper part of permafrost exposure at Mamontova Gora (Yakutiya, Russia) are presented. To increase reliability of the results, suspensions of two microbial species and two coliphage species were intro- duced as biomarkers directly on the surface of thaing ice and in the meltwater flow. Each of the four different model biological objects was shown to possess unique parameters of movement in the meltwater flow and is able to move 132 m in 25-35 min with the water flow.
[Mh] Termos MeSH primário: Colífagos/fisiologia
Corynebacterium/fisiologia
Movimento/fisiologia
Pergelissolo/microbiologia
Rios/microbiologia
Yarrowia/fisiologia
[Mh] Termos MeSH secundário: Gelo/análise
Modelos Biológicos
Organismos Geneticamente Modificados
Transição de Fase
Reologia/métodos
Estações do Ano
Sibéria
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ice)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180208
[Lr] Data última revisão:
180208
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180125
[St] Status:MEDLINE


  2 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27770504
[Au] Autor:Chasmer L; Hopkinson C
[Ad] Endereço:Department of Geography, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
[Ti] Título:Threshold loss of discontinuous permafrost and landscape evolution.
[So] Source:Glob Chang Biol;23(7):2672-2686, 2017 07.
[Is] ISSN:1365-2486
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:This study demonstrates linkages between the 1997/1998 El Niño/Southern Oscillation index and a threshold shift to increased permafrost loss within a southern Taiga Plains watershed, Northwest Territories, Canada. Three-dimensional contraction of permafrost plateaus and changes in vegetation structural characteristics are determined from multitemporal airborne Light Detection And Ranging (LiDAR) surveys in 2008, 2011 and 2015. Morphological changes in permafrost cover are compared with optical image analogues from 1970, 1977, 2000 and 2008 and time-series hydro-climate data. Results demonstrate that significant changes in air temperature, precipitation, runoff and a shortening of the snow-covered season by 35 days (1998-2014) and 50 days (1998 only) occurred after 1997. The albedo reduction associated with 35 and 50 days less snow cover leads to increases in shortwave energy receipt during the active thaw period of ~12% (3% annually) and ~16% (5% annually), respectively. From 2000 to 2015, sporadic permafrost loss accelerated from 0.19% (of total basin area) per year between 1970 and 2000 to 0.58% per year from 2000 to 2015, with a projected total loss of permafrost by ~2044. From ~1997 to 2011, we observe a corresponding shift to increased runoff ratio. However, observed increases in the proportion of snow precipitation and the volumetric contribution of permafrost loss to runoff post-1997 (0.6-6.4% per year) cannot fully explain this shift. This suggests increases in drainage efficiency and possible losses from long-term groundwater storage as a result of subtle terrain morphological and soil zone hydraulic conductivity changes. These hydrological changes appear coincident with high vegetation mortality at plateau margins combined with succession-related canopy growth in some bog and fen areas, which are presumed to be drying. Similar changes in runoff response were observed at adjacent Birch, Trout and Jean Marie River watersheds indicating that observations are representative of northern Boreal sporadic permafrost/wetland watersheds in the Taiga Plains.
[Mh] Termos MeSH primário: Pergelissolo
Taiga
[Mh] Termos MeSH secundário: Canadá
Clima
Territórios do Noroeste
Plantas
Estações do Ano
Movimentos da Água
Zonas Úmidas
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1710
[Cu] Atualização por classe:180123
[Lr] Data última revisão:
180123
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161023
[St] Status:MEDLINE
[do] DOI:10.1111/gcb.13537


  3 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28749495
[Au] Autor:Pedroso MM; Selleck C; Enculescu C; Harmer JR; Mitic N; Craig WR; Helweh W; Hugenholtz P; Tyson GW; Tierney DL; Larrabee JA; Schenk G
[Ad] Endereço:School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia. m.pedroso@uq.edu.au schenk@uq.edu.au.
[Ti] Título:Characterization of a highly efficient antibiotic-degrading metallo-ß-lactamase obtained from an uncultured member of a permafrost community.
[So] Source:Metallomics;9(8):1157-1168, 2017 Aug 16.
[Is] ISSN:1756-591X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Antibiotic resistance is a major global health problem, one that threatens to derail the benefits garnered from arguably the greatest success of modern medicine, the discovery of antibiotics. Among the most potent agents contributing to antibiotic resistance are metallo-ß-lactamases (MBLs). The discovery of MBL-like enzymes in microorganisms that are not in contact with the human population is of particular concern as these proteins already have the in-built capacity to inactivate antibiotics, even though they may not need MBL activity for their survival. Here, we demonstrate that a microbiome from a remote and frozen environment in Alaska harbours at least one highly efficient MBL, LRA-8. LRA-8 is homologous to the B3 subgroup of MBLs and has a substrate profile and catalytic properties similar to well-known members of this enzyme family, which are expressed by major human pathogens. LRA-8 is predominantly a penicillinase, but is also active towards carbapenems, but not cephalosporins. Spectroscopic studies indicate that LRA-8 has an active site structure similar to that of other MBLs (in particular B3 subgroup representative AIM-1), and a combination of steady-state and pre-steady-state kinetic data demonstrate that the enzyme is likely to employ a metal ion-bridging hydroxide to initiate catalysis. The rate-limiting step is the decay of a chromophoric, tetrahedral intermediate, as is observed in various other MBLs. Thus, studying the properties of such "pristine" MBL-like proteins may provide insight into the structural plasticity of this family of enzymes that may facilitate functional promiscuity, while important insight into the evolution of MBLs may also be gained.
[Mh] Termos MeSH primário: Antibacterianos/metabolismo
Proteínas de Bactérias/metabolismo
Pergelissolo/microbiologia
beta-Lactamases/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Catálise
Seres Humanos
Metagenoma
Metais/metabolismo
Modelos Moleculares
Fenótipo
Homologia de Sequência
Especificidade por Substrato
beta-Lactamases/química
beta-Lactamases/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (Metals); EC 3.5.2.6 (beta-Lactamases)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170728
[St] Status:MEDLINE
[do] DOI:10.1039/c7mt00195a


  4 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29182670
[Au] Autor:Crevecoeur S; Vincent WF; Comte J; Matveev A; Lovejoy C
[Ad] Endereço:Département de Biologie, Centre d'études nordiques (CEN) and Takuvik Joint International Laboratory, Université Laval, Québec, Québec, Canada.
[Ti] Título:Diversity and potential activity of methanotrophs in high methane-emitting permafrost thaw ponds.
[So] Source:PLoS One;12(11):e0188223, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lakes and ponds derived from thawing permafrost are strong emitters of carbon dioxide and methane to the atmosphere, but little is known about the methane oxidation processes in these waters. Here we investigated the distribution and potential activity of aerobic methanotrophic bacteria in thaw ponds in two types of eroding permafrost landscapes in subarctic Québec: peatlands and mineral soils. We hypothesized that methanotrophic community composition and potential activity differ regionally as a function of the landscape type and permafrost degradation stage, and locally as a function of depth-dependent oxygen conditions. Our analysis of pmoA transcripts by Illumina amplicon sequencing and quantitative PCR showed that the communities were composed of diverse and potentially active lineages. Type I methanotrophs, particularly Methylobacter, dominated all communities, however there was a clear taxonomic separation between the two landscape types, consistent with environmental control of community structure. In contrast, methanotrophic potential activity, measured by pmoA transcript concentrations, did not vary with landscape type, but correlated with conductivity, phosphorus and total suspended solids. Methanotrophic potential activity was also detected in low-oxygen bottom waters, where it was inversely correlated with methane concentrations, suggesting methane depletion by methanotrophs. Methanotrophs were present and potentially active throughout the water column regardless of oxygen concentration, and may therefore be resilient to future mixing and oxygenation regimes in the warming subarctic.
[Mh] Termos MeSH primário: Metano/metabolismo
Methylococcaceae/metabolismo
Pergelissolo
Tanques
[Mh] Termos MeSH secundário: Genes Bacterianos
Methylococcaceae/classificação
Methylococcaceae/genética
Filogenia
Reação em Cadeia da Polimerase em Tempo Real
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
OP0UW79H66 (Methane)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171226
[Lr] Data última revisão:
171226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171129
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188223


  5 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28916375
[Au] Autor:Brouchkov A; Kabilov M; Filippova S; Baturina O; Rogov V; Galchenko V; Mulyukin A; Fursova O; Pogorelko G
[Ad] Endereço:Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia; Tyumen State University, Volodarskogo 6, Tyumen 625003, Russia.
[Ti] Título:Bacterial community in ancient permafrost alluvium at the Mammoth Mountain (Eastern Siberia).
[So] Source:Gene;636:48-53, 2017 Dec 15.
[Is] ISSN:1879-0038
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Permanently frozen (approx. 3.5Ma) alluvial Neogene sediments exposed in the Aldan river valley at the Mammoth Mountain (Eastern Siberia) are unique, ancient, and poorly studied permafrost environments. So far, the structure of the indigenous bacterial community has remained unknown. Use of 16S metagenomic analysis with total DNA isolation using DNA Spin Kit for Soil (MO-Bio) and QIAamp DNA Stool Mini Kit (Qiagen) has revealed the major and minor bacterial lineages in the permafrost alluvium sediments. In sum, 61 Operational Taxonomic Units (OTUs) with 31,239 reads (Qiagen kit) and 15,404 reads (Mo-Bio kit) could be assigned to the known taxa. Only three phyla, Bacteroidetes, Proteobacteria and Firmicutes, comprised >5% of the OTUs abundance and accounted for 99% of the total reads. OTUs pertaining to the top families (Chitinophagaceae, Caulobacteraceae, Sphingomonadaceae, Bradyrhizobiaceae, Halomonadaceae) held >90% of reads. The abundance of Actinobacteria was less (0.7%), whereas members of other phyla (Deinococcus-Thermus, Cyanobacteria/Chloroplast, Fusobacteria, and Acidobacteria) constituted a minor fraction of reads. The bacterial community in the studied ancient alluvium differs from other permafrost sediments, mainly by predominance of Bacteroidetes (>52%). The diversity of this preserved bacterial community has the potential to cause effects unknown if prompted to thaw and spread with changing climate. Therefore, this study elicits further reason to study how reintroduction of these ancient bacteria could affect the surrounding ecosystem, including current bacterial species.
[Mh] Termos MeSH primário: Bactérias/isolamento & purificação
Pergelissolo/microbiologia
[Mh] Termos MeSH secundário: Bactérias/classificação
Bactérias/genética
Sedimentos Geológicos/química
Sedimentos Geológicos/microbiologia
Metagenômica
RNA Ribossômico 16S/genética
Sibéria
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170917
[St] Status:MEDLINE


  6 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28675586
[Au] Autor:Keuper F; Dorrepaal E; van Bodegom PM; van Logtestijn R; Venhuizen G; van Hal J; Aerts R
[Ad] Endereço:Systems Ecology, Department of Ecological Science, VU University Amsterdam, Amsterdam, The Netherlands.
[Ti] Título:Experimentally increased nutrient availability at the permafrost thaw front selectively enhances biomass production of deep-rooting subarctic peatland species.
[So] Source:Glob Chang Biol;23(10):4257-4266, 2017 Oct.
[Is] ISSN:1365-2486
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Climate warming increases nitrogen (N) mineralization in superficial soil layers (the dominant rooting zone) of subarctic peatlands. Thawing and subsequent mineralization of permafrost increases plant-available N around the thaw-front. Because plant production in these peatlands is N-limited, such changes may substantially affect net primary production and species composition. We aimed to identify the potential impact of increased N-availability due to permafrost thawing on subarctic peatland plant production and species performance, relative to the impact of increased N-availability in superficial organic layers. Therefore, we investigated whether plant roots are present at the thaw-front (45 cm depth) and whether N-uptake ( N-tracer) at the thaw-front occurs during maximum thaw-depth, coinciding with the end of the growing season. Moreover, we performed a unique 3-year belowground fertilization experiment with fully factorial combinations of deep- (thaw-front) and shallow-fertilization (10 cm depth) and controls. We found that certain species are present with roots at the thaw-front (Rubus chamaemorus) and have the capacity (R. chamaemorus, Eriophorum vaginatum) for N-uptake from the thaw-front between autumn and spring when aboveground tissue is largely senescent. In response to 3-year shallow-belowground fertilization (S) both shallow- (Empetrum hermaphroditum) and deep-rooting species increased aboveground biomass and N-content, but only deep-rooting species responded positively to enhanced nutrient supply at the thaw-front (D). Moreover, the effects of shallow-fertilization and thaw-front fertilization on aboveground biomass production of the deep-rooting species were similar in magnitude (S: 71%; D: 111% increase compared to control) and additive (S + D: 181% increase). Our results show that plant-available N released from thawing permafrost can form a thus far overlooked additional N-source for deep-rooting subarctic plant species and increase their biomass production beyond the already established impact of warming-driven enhanced shallow N-mineralization. This may result in shifts in plant community composition and may partially counteract the increased carbon losses from thawing permafrost.
[Mh] Termos MeSH primário: Biomassa
Pergelissolo
Solo
[Mh] Termos MeSH secundário: Mudança Climática
Nitrogênio
Plantas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Soil); N762921K75 (Nitrogen)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170705
[St] Status:MEDLINE
[do] DOI:10.1111/gcb.13804


  7 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28208232
[Au] Autor:Mauritz M; Bracho R; Celis G; Hutchings J; Natali SM; Pegoraro E; Salmon VG; Schädel C; Webb EE; Schuur EAG
[Ad] Endereço:Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
[Ti] Título:Nonlinear CO flux response to 7 years of experimentally induced permafrost thaw.
[So] Source:Glob Chang Biol;23(9):3646-3666, 2017 Sep.
[Is] ISSN:1365-2486
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7 years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (R ), gross primary productivity (GPP), and net summer CO storage (NEE). Over 7 years R , GPP, and NEE also increased in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, R , GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed R , GPP, and NEE. However R and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher R in deeply thawed areas during summer months was balanced by GPP. Summer CO flux across treatments fit a single quadratic relationship that captured the functional response of CO flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO flux: plant growth and water table dynamics. Nonsummer R models estimated that the area was an annual CO source during all years of observation. Nonsummer CO loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO source.
[Mh] Termos MeSH primário: Ciclo do Carbono
Pergelissolo
[Mh] Termos MeSH secundário: Regiões Árticas
Dióxido de Carbono
Solo
Tundra
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Soil); 142M471B3J (Carbon Dioxide)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170217
[St] Status:MEDLINE
[do] DOI:10.1111/gcb.13661


  8 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28116688
[Au] Autor:Lund M; Stiegler C; Abermann J; Citterio M; Hansen BU; van As D
[Ad] Endereço:Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark. ml@bios.au.dk.
[Ti] Título:Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland.
[So] Source:Ambio;46(Suppl 1):81-93, 2017 Feb.
[Is] ISSN:1654-7209
[Cp] País de publicação:Sweden
[La] Idioma:eng
[Ab] Resumo:The surface energy balance (SEB) is essential for understanding the coupled cryosphere-atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic.
[Mh] Termos MeSH primário: Mudança Climática
Monitorização de Parâmetros Ecológicos
Conceitos Meteorológicos
[Mh] Termos MeSH secundário: Regiões Árticas
Groenlândia
Camada de Gelo
Pergelissolo
Neve
Tundra
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170125
[St] Status:MEDLINE
[do] DOI:10.1007/s13280-016-0867-5


  9 / 101 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28116680
[Au] Autor:Parmentier FW; Christensen TR; Rysgaard S; Bendtsen J; Glud RN; Else B; van Huissteden J; Sachs T; Vonk JE; Sejr MK
[Ad] Endereço:Norwegian Institute of Bioeconomy Research, Høyskoleveien 7, 1430, Ås, Norway. frans-jan@thissideofthearctic.org.
[Ti] Título:A synthesis of the arctic terrestrial and marine carbon cycles under pressure from a dwindling cryosphere.
[So] Source:Ambio;46(Suppl 1):53-69, 2017 Feb.
[Is] ISSN:1654-7209
[Cp] País de publicação:Sweden
[La] Idioma:eng
[Ab] Resumo:The current downturn of the arctic cryosphere, such as the strong loss of sea ice, melting of ice sheets and glaciers, and permafrost thaw, affects the marine and terrestrial carbon cycles in numerous interconnected ways. Nonetheless, processes in the ocean and on land have been too often considered in isolation while it has become increasingly clear that the two environments are strongly connected: Sea ice decline is one of the main causes of the rapid warming of the Arctic, and the flow of carbon from rivers into the Arctic Ocean affects marine processes and the air-sea exchange of CO . This review, therefore, provides an overview of the current state of knowledge of the arctic terrestrial and marine carbon cycle, connections in between, and how this complex system is affected by climate change and a declining cryosphere. Ultimately, better knowledge of biogeochemical processes combined with improved model representations of ocean-land interactions are essential to accurately predict the development of arctic ecosystems and associated climate feedbacks.
[Mh] Termos MeSH primário: Ciclo do Carbono
Mudança Climática
Camada de Gelo
[Mh] Termos MeSH secundário: Regiões Árticas
Monitorização de Parâmetros Ecológicos
Oceanos e Mares
Pergelissolo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170125
[St] Status:MEDLINE
[do] DOI:10.1007/s13280-016-0872-8


  10 / 101 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28068392
[Au] Autor:Wang Z; Wang Q; Wu X; Zhao L; Yue G; Nan Z; Wang P; Yi S; Zou D; Qin Y; Wu T; Shi J
[Ad] Endereço:Guizhou Institute of Prataculture, Guizhou Academy of Agricultural Sciences, Guiyang, China.
[Ti] Título:Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.
[So] Source:PLoS One;12(1):e0169732, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) product based on turning points (TPs), which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI) and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost regions than the environmental factors (including permafrost) related to the underlying surface conditions.
[Mh] Termos MeSH primário: Altitude
Ecossistema
Monitoramento Ambiental
Pergelissolo
[Mh] Termos MeSH secundário: Algoritmos
China
Meio Ambiente
Geografia
Modelos Teóricos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170810
[Lr] Data última revisão:
170810
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170110
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0169732



página 1 de 11 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde