Toxic metal enrichment and boating intensity: sediment records of antifoulant copper in shallow lakes of eastern England     

John F. Boyle  Carl D. Sayer  Dan Hoare  Helen Bennion  Kate Heppel  Stephen J. Lambert  Peter G. Appleby  Neil L. Rose  Anthony J. Davy 《Journal of Paleolimnology》2016,55(3):195-208

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Midge (Diptera: Chironomidae and Ceratopogonidae) emergence responses to temperature: experiments to assess midges’ capacity as paleotemperature indicators     

Trapper R. Dickson  Ian R. Walker 《Journal of Paleolimnology》2015,53(2):165-176

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Equipped to deal with uncertainty in climate and impacts predictions: lessons from internal peer review   总被引：1，自引：0，他引：1  

Anna Wesselink  Andrew Juan Challinor  James Watson  Keith Beven  Icarus Allen  Helen Hanlon  Ana Lopez  Susanne Lorenz  Friederike Otto  Andy Morse  Cameron Rye  Stephane Saux-Picard  David Stainforth  Emma Suckling 《Climatic change》2015,132(1):1-14

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A participatory systems approach to understanding climate adaptation needs     

Helen Ross  Sylvie Shaw  David Rissik  Neil Cliffe  Susie Chapman  Vanessa Hounsell  James Udy  Nghia Trong Trinh  Jess Schoeman 《Climatic change》2015,129(1-2):27-42

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Abrupt Holocene climate change and potential response to solar forcing in western Canada     

Daniel G. Gavin  Andrew C.G. Henderson  Karlyn S. Westover  Sherilyn C. Fritz  Ian R. Walker  Melanie J. Leng  Feng Sheng Hu 《Quaternary Science Reviews》2011,30(9-10):1243-1255

Several abrupt climate events during the Holocene, including the widely documented oscillation at 8.2 thousand years before present (ka), are attributed to changes in the North Atlantic thermohaline circulation. Additional mechanisms, such as interactions between atmospheric circulation, ice-sheet dynamics, and the influence of solar irradiance, also have been proposed to explain abrupt climatic events, but evidence remains elusive. This study presents evidence from multi-proxy analyses on the Holocene sediments of Eleanor Lake, interior British Columbia. Climatic inferences from our decadal-resolution record of biogenic silica (BSi) abundance are supported by changes in diatom and pollen assemblages from the same core and correlations with existing regional climate records. The BSi record reveals abrupt and persistent climatic shifts at 10.2, 9.3, and 8.5 ka, the latter two of which are coeval with major collapses of the Laurentide Ice Sheet. The record also reveals a short-term cooling at 8.2 ka that is distinct from the 8.5 ka event and similar in magnitude to several other late-Holocene coolings. BSi is correlated with solar-irradiance indices (r = 0.43–0.61), but the correlation is opposite in sign to that expected from direct solar forcing and weakens after 8 ka. Possible mechanisms causing the abrupt and persistent climate changes of the early Holocene include 1) sudden losses of ice and proglacial lake extent, causing a shift in the meridional structure of atmospheric circulation, 2) a possible link between solar minima and El Niño-like conditions that are correlated with warm spring temperature in interior British Columbia, and 3) the influence of solar irradiance variability on the position of the polar jet, possibly via effects on the strength of the glacial anticyclone.  相似文献   

Natural aggregates in the performance and durability of concrete: physical characteristics     

Peter G. Fookes  Mike J. Walker 《Geology Today》2011,27(4):141-148

The production of rock aggregates for construction is the largest of the extractive industries in Britain. Natural aggregates form the main component, by volume, in the manufacture of concrete but the part played by aggregates in the durability and performance aspects of concrete is still only moderately understood. This feature summarizes the main characteristics of common aggregate in concrete, especially those leading to cracking and deterioration. Physical and mechanical causes of concrete cracking are of immense importance but are omitted from the following. The feature expands on the earlier one: ‘Concrete: a man‐made rock?’ (Geology Today, 2010, v.26, n.2). To follow is another that will continue the story by looking at chemical reactivity in concretes.  相似文献   

Selecting MPAs to conserve groundfish biodiversity: the consequences of failing to account for catchability in survey trawls     

Fraser  Helen M.; Greenstreet  S. P. R.; Piet  Gerjan J. 《ICES Journal of Marine Science》2009,66(1):82-89

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Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement   总被引：1，自引：0，他引：1  

Greenstreet  Simon P. R.; Fraser  Helen M.; Piet  Gerjan J. 《ICES Journal of Marine Science》2009,66(1):90-100

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Effects of the suspension feeding mussel Mytilus trossulus on a brackish water macroalgal and associated invertebrate community     

Jonne Kotta  Kristjan Herkül  Ilmar Kotta  Helen Orav-Kotta  & Velda Lauringson 《Marine Ecology》2009,30(S1):56-64

The importance of suspension-feeding mussels is particularly apparent in benthic communities; however, the role of this feeding strategy on the development of macroalgal and associated invertebrate communities is in general poorly known. The effect of suspension-feeding mussels Mytilus trossulus on benthic communities was studied in an in situ factorial field experiment in the Northern Baltic Sea over one ice-free season. The experiment was performed under different regimes of wave exposure (low and moderate) and on different sedimentary habitats (soft bottom with high organic content, soft bottom with low organic content, and hard bottom). In general the presence of mussels was associated with increased biomass of filamentous algae, herbivores and deposit feeders and decreased biomass of charophytes. The effect of M. trossulus interacted with the effect of exposure and substrate. Stronger responses were observed in moderately exposed than in sheltered areas. The presence of M. trossulus affected charophytes and deposit feeders on sand with low content of organic matter and filamentous algae on pebbles but not on other substrate types. The magnitude of the effects varied between months. The results suggest that (i) even in dynamic coastal systems the biodeposits and excretions of mussels are at least partly assimilated locally and are not flushed away to the open sea, (ii) the accumulation of faecal material induced elevated growth of deposit feeders, (iii) mussels enhanced the growth of ephemeral macroalgae and reduced the growth of perennial macroalgae, and (iv) together with increasing benthic primary production, mussels indirectly increase the production of herbivores.  相似文献   

Comparison of benthic and pelagic suspension feeding in shallow water habitats of the Northeastern Baltic Sea   总被引：1，自引：0，他引：1  

Velda Lauringson  Jonne Kotta  Helen Orav-Kotta  Ilmar Kotta  Kristjan Herkül  & Arno Põllumäe 《Marine Ecology》2009,30(S1):43-55

Combining field experiments with the biomass distribution data of dominant suspension feeders we compared the benthic and pelagic suspension feeding rates in shallow non-tidal brackish water coastal habitats. We found that pelagic grazing exceeded benthic grazing in almost all cases, on average from 14 to 4819 times depending on the site. Benthic grazing rates were related to site-specific environmental parameters and showed no relationship with water chlorophyl a (Chl a ) content, whereas pelagic grazing rates varied both spatially and temporally and were related to water Chl a content. Our results indicate that in several shallow coastal habitats, pelagic suspension feeding substantially exceeds benthic suspension feeding. This suggests that pelagic recycling is higher than the amounts of energy redirected from pelagic to benthic food webs by benthic suspension feeders. These results increase our knowledge of the energy flows in coastal ecosystems.  相似文献