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| Registros recuperados: 29 | |
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| Roubik, David Ward; Smithsonian Tropical Research Institute; roubikd@tivoli.si.edu. |
| Plant-pollinator systems inherently possess wide variation that limits the applicability of surveys on population dynamics or diversity. Stable habitats are scarcely studied, whereas dynamics in unprotected habitats are less predictable or more compromised by exotic organisms (Apis, in the case of bee surveys). An extensively replicated, long-term study of orchid-bees (Euglossini) was made in protected tropical moist forest in Panama. Over 47,000 bees were recorded in 124 monthly censuses employing 1952 counts. No aggregate trend in abundance occurred (from 1979 to 2000), although four individual species declined, nine increased, 23 showed no change, and species richness was stable. No rare or parasitic species showed decreasing trends, while the most... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: ENSO; Euglossini; Abundance variability; Bees; Census techniques; Diversity; Pollinators; Trends; Tropical- temperate comparisons. |
| Ano: 2001 |
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| Pujos, M; Latouche, C; Maillet, N. |
| Marine muds deposited on the French Guiana coast mostly originate in the Amazon. Recent sediments are composed of (a) illite (33 %) and chlorite (13 %) of Andean mountain origin; and (b) kaolinite (28 %) and smectite (26 %), principally from the Amazonian lowlands but also from the Guiana Shield. In the coastal mud prism, high-resolution seismic profiles, together with sedimentological, micropaleontological and soil engineering studies, supplemented by C-14 dates, permitted a stratigraphic interpretation of eight cores. Three episodes have been determined on the basis of clay-mineral variations related to Amazonian lowland, Andean and Guiana shield sources. The older episodes 3 (3000-1700 y BP) and 2 (1700-1000 y BP) are predominantly characterized by... |
| Tipo: Text |
Palavras-chave: Late quaternary; French Guiana; Shelf; Clay minerals; ENSO. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20506/18175.pdf |
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| Bayon, Germain; Schefuss, Enno; Dupont, Lydie; Borges, Alberto V.; Dennielou, Bernard; Lambert, Thibault; Mollenhauer, Gesine; Monin, Laurence; Ponzevera, Emmanuel; Skonieczny, Charlotte; Andre, Luc. |
| There is increasing evidence that abrupt vegetation shifts and large-scale erosive phases occurred in Central Africa during the third millennium before present. Debate exists as to whether these events were caused by climate change and/or intensifying human activities related to the Bantu expansion. In this study, we report on a multi-proxy investigation of a sediment core (KZR-23) recovered from the Congo submarine canyon. Our aim was to reconstruct climate, erosion and vegetation patterns in the Congo Basin for the last 10,000 yrs, with a particular emphasis on the late Holocene period. Samples of modern riverine suspended particulates were also analyzed to characterize sediment source geochemical signatures from across the Congo watershed. We find that... |
| Tipo: Text |
Palavras-chave: Neodymium isotopes; Suspended particulates; Congo Basin; ENSO; Human land-use; Deforestation. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00463/57467/59747.pdf |
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| Praveen Kumar, B.; Vialard, J.; Lengaigne, M.; Murty, V. S. N.; Foltz, G. R.; Mcphaden, M. J.; Pous, S.; De Boyer Montegut, Clement. |
| Sea-surface temperature interannual anomalies (SSTAs) in the thermocline ridge of the southwestern tropical Indian Ocean (TRIO) have several well-documented climate impacts. In this paper, we explore the physical processes responsible for SSTA evolution in the TRIO region using a combination of observational estimates and model-derived surface layer heat budget analyses. Vertical oceanic processes contribute most to SSTA variance from December to June, while lateral advection dominates from July to November. Atmospheric fluxes generally damp SSTA generation in the TRIO region. As a result of the phase opposition between the seasonal cycle of vertical processes and lateral advection, there is no obvious peak in SSTA amplitude in boreal winter, as previously... |
| Tipo: Text |
Palavras-chave: Thermocline ridge of the Indian Ocean; Surface temperature interannual variability; ENSO; IOD. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00185/29642/28051.pdf |
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| Rustic, Gerald Thomas. |
| The El Niño Southern Oscillation (ENSO) has been implicated in large-scale climate shifts of the past millennia, but paleoclimate records from the dynamically vital eastern equatorial Pacific Ocean (EEP) spanning the past millennium are sparse. This has limited our understanding of tropical Pacific dynamics, leaving questions regarding the source of ENSO variability unanswered. Here I seek to address some of these questions regarding relationship between ENSO and tropical Pacific mean state, and the relationship between the tropical Pacific and large-scale climate. Mean EEP sea surface temperature (SST) for the past millennium was reconstructed using Mg/Ca ratios in Globigerinoides ruber from a sub-centennially resolved sediment core collected near the... |
| Tipo: Text |
Palavras-chave: Eastern tropical pacific; ENSO; Foraminifera; Paleoceanography; Paleoclimate. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00495/60657/64154.pdf |
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| Pan, Huanglei; Yu, Xiaolong; Liu, Dishi; Shi, Dalin; Yang, Shengyun; Pan, Weiran. |
| A physical–biological ocean model was employed to investigate characteristics of the Beibu Gulf in the northwest South China Sea (SCS) from 2011 to 2015. We adopted the spatially constrained multivariate clustering method to determine the refined marine environmental regionalization using 10 variables from the model output, and compared regionalization differences in ENSO (El Niño–Southern Oscillation) years. The simulated physical and biochemical variables display a wide spectrum of patterns in space and time. The regionalization maps indicated that the Qiongzhou Strait and its adjacent area can be classified as a separate region, characterized by the rich presence of nutrients, phytoplankton, zooplankton, and detritus, owing to the water invasion from... |
| Tipo: Text |
Palavras-chave: Beibu Gulf; Physical-biological model; Regionalization; Multivariate clustering; ENSO. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00679/79109/81600.pdf |
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| Durand, F; Alory, Gael; Dussin, Raphael; Reul, Nicolas. |
| The tropical Indian Ocean experiences an interannual mode of climatic variability, known as the Indian Ocean Dipole (IOD). The signature of this variability in ocean salinity is hypothesized based on modeling and assimilation studies, on account of scanty observations. Soil Moisture and Ocean Salinity (SMOS) satellite has been designed to take up the challenge of sea surface salinity remote sensing. We show that SMOS data can be used to infer the pattern of salinity variability linked with the IOD events. The core of maximum variability is located in the central tropical basin, south of the equator. This region is anomalously salty during the 2010 negative IOD event, and anomalously fresh during the 2011 positive IOD event. The peak-to-peak anomaly exceeds... |
| Tipo: Text |
Palavras-chave: SSS; Indian Ocean Dipole; SMOS; ARGO; ENSO. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00161/27234/25481.pdf |
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| Lea, Mary-anne; Guinet, Christophe; Cherel, Yves; Duhamel, Guy; Dubroca, Laurent; Pruvost, Patrice; Hindell, Mark. |
| The large temporal and spatial variability in marine productivity encountered by marine predators may negatively influence breeding success. The Antarctic fur seal Arctocephalus gazella (AFS), a marine predator in the Southern Ocean (SO) ecosystem with a circumpolar distribution, exhibits a short, 4 mo lactation coinciding with increased summer marine productivity. The diet of AFS, and the distance to significant and productive oceanographic features, such as the Antarctic Polar Frontal Zone (PFZ), varies considerably between populations. We studied the foraging activity, foraging efficiency and the pup provisioning strategies of lactating AFS at a key breeding site in the southern Indian Ocean, the Kerguelen Archipelago. Foraging parameters were examined... |
| Tipo: Text |
Palavras-chave: Antarctic fur seal; Polar front; Pinniped; ENSO; Foraging; Growth; Diving; Seabird; Myctophid; Maternal care. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00247/35847/34356.pdf |
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| Owen,Robert D. |
| The Cerrado extends as islands or patches into the Upper Paraná Atlantic Forest (UPAF) of Brazil and Paraguay. This study evaluates the temporal dynamics of a marginal terrestrial small-mammal community in an isolated Cerrado patch within the UPAF, at the southwestern distributional limit of the Cerrado and near the western limit of the UPAF in eastern Paraguay. Because the faunal members of marginal communities are living near the limits of their capabilities in terms of their abiotic and biotic environment, the communities in such areas are likely to be a mixture of Cerrado and UPAF species, sensitive to extrinsic variables such as climate change and anthropogenic changes in land use. In this 23-month study, temporal dynamics of a terrestrial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cricetidae; Didelphidae; Echimyidae; Fire; ENSO; Precipitation. |
| Ano: 2013 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-93832013000100007 |
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| Keil, Alwin; Teufel, Nils; Gunawan, Dodo; Leemhuis, Constanze. |
| Crop production in the tropics is subject to considerable climate variability caused by the El Niño-Southern Oscillation (ENSO) phenomenon. In Southeast Asia, El Niño causes comparatively dry conditions leading to substantial declines of crop yields with severe consequences for the welfare of local farm households. Using a modelling approach that combines regression analysis with linear programming and stochastic simulation, and integrates climatic and hydrologic modelling results, the objective of this paper is to assess the impact of El Niño on agricultural incomes of smallholder farmers in Central Sulawesi, Indonesia, and to identify suitable crop management strategies to mitigate the income depressions. The results contribute to the formulation of... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: ENSO; Risk management; Linear programming; Stochastic simulation; Indonesia; Farm Management. |
| Ano: 2007 |
URL: http://purl.umn.edu/7942 |
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| Wernstedt, Kris; Hersh, Robert. |
| Recent scientific and technical advances have increased the potential use of long-term seasonal climate forecasts for improving water resource management. This paper examines the role that forecasts, in particular those based on the El Nino-Southern Oscillation (ENSO) cycle, can play in flood planning in the Pacific Northwest. While strong evidence of an association between ENSO signals and flooding in the region exists, this association is open to more than one interpretation depending on: a) the metric used to test the strength of the association; b) the definition of critical flood events; c) site-specific features of watersheds; and d) the characteristics of flood management institutions. A better understanding and appreciation of such ambiguities,... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Flooding; Climate; ENSO; Water resources planning; Water policy; Water management; Resource /Energy Economics and Policy; Q2. |
| Ano: 2001 |
URL: http://purl.umn.edu/10603 |
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| Wernstedt, Kris; Hersh, Robert. |
| We examine the use of El Nino-Southern Oscillation (ENSO) forecasts for flood planning in the Pacific Northwest. Using theories of resource mobilization as a conceptual foundation, the paper relies on: 1) case studies of three communities vulnerable to flooding that have had access to long-term forecasts of ENSO conditions; and 2) analysis of data collected from a survey of nearly 60 local emergency managers, planners, and public works staff. We find that understanding the regulatory machinery and other institutions involved in using climate forecasts is critical to more effective use of these forecasts. Forecast use could be promoted by: 1) an extension service to broker climate information; 2) the identification or creation of federal authorities to fund... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Flooding; ENSO; La Nina; Climate variability; Climate forecast; Natural hazards; Water policy; Resource /Energy Economics and Policy; Q2. |
| Ano: 2002 |
URL: http://purl.umn.edu/10813 |
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| Registros recuperados: 29 | |
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