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71.
Joanne?C.?Bintz Scott?W.?NixonEmail author Betty?A.?Buckley Stephen?L.?Granger 《Estuaries and Coasts》2003,26(3):765-776
We investigated the independent and interactive effects of nutrient loading and summer water temperature on phytoplankton,
drift macroalgae, and eelgrass (Zostera marina) in a coastal lagoon mesocosm experiment conducted from May through August 1999. Temperature treatments consisted of controls
that approximated the 9-yr mean daily temperatures for Ninigret and Point Judith Lagoons in Rhode Island (United States) and
treatments approximately 4°C above and 4°C below the controls. Nutrient treatments consisted of the addition of 6 mmol N m−2d−1 and 0.5 mmol P m−2 d−1 to mesocosms 4°C above and 4°C below the 9-yr daily mean. Nutrient enrichment produced marked phytoplankton blooms in both
cool and warm treatments during early summer. These were replaced after midsummer by dramatic growths of macroalgal mats ofEnteromorpha flexuosa and, to a lesser degree,Cladophora sericea. No phytoplankton blooms were observed in the cool unenriched treatments, but blooms did develop in the mean temperature
and warm mesocosms during the second half of the summer that were similar in intensity, though of shorter duration, than those
observed earlier in the enriched systems. Macroalgal blooms did not occur in the unenriched mesocosms. Sustained warm water
temperatures markedly decreased eelgrass density and belowground production and increased the time interval between the initiation
of new leaves, particuarly when the biomass of macroalgae was high. The negative effect of elevated water temperature on eelgrass
was significantly increased under conditions of elevated inorganic nutrient input. By the end of summer, virtually all of
the measures of eelgrass health declined in rank order from cool, to mean, to cool enriched, to warm, to warm enriched treatments.
It is likely that the marked declines in eelgrass abundance observed during recent decades in the Northeast have resulted
from an interaction of increasing nutrient enrichment combined with increasing summer water temperatures. 相似文献
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73.
Joanne M. R. Fernlund 《第四纪科学杂志》1993,8(1):67-78
Radiocarbon dates of shells from the long singular ridges belonging to the Halland Coastal Moraines indicate that the ridges are younger than 12 400 yr BP, whereas according to the existing chronostratigraphy of western Sweden, the area was ice free before 12 700 yr BP. The ridges are interpreted as push moraines and not deposits of a stationary ice margin. The chronostratigraphy of western Sweden seems to need revision; however, further study is necessary before it is possible to present a new model. 相似文献
74.
Rachel Bynoe Nick M. Ashton Tim Grimmer Peter Hoare Joanne Leonard Simon G. Lewis Darren Nicholas Simon Parfitt 《第四纪科学杂志》2021,36(2):191-210
Recent archaeological discoveries from exposures of the Cromer Forest-bed Formation at Happisburgh, UK, have radically changed interpretations of the nature and timing of early hominin occupation of northern latitudes, but this in situ archaeology is only one part of the picture. Surface finds of Pleistocene mammalian remains have been found along this coastline for centuries, with stone tools adding to this record over the past 7 years. The ex situ nature of these finds, however, means they are often seen as limited in the information they can provide. This work contributes to a growing body of research from a range of landscape and environmental contexts that seeks to demonstrate the value and importance of these ex situ assemblages. Here the focus is on Palaeolithic flint artefacts and Pleistocene mammalian remains recovered by a group of local collectors through systematic, GPS-recorded beach collection from 2013 to 2017, and their use in developing a methodology for working with ex situ Palaeolithic finds in coastal locations. The results demonstrate significant patterning that identifies unexplored exposures both onshore and offshore, considerably expanding the known extent of deposits and facilitating new insights into the wider archaeological landscape associated with the earliest occupation of northern Europe. 相似文献
75.
The present study describes a procedure for quantitatively analyzing satellite telemetry data to identify interspecific land use differences among four threatened crane species. The inherent inaccuracy of satellite telemetry data points, the temporal autocorrelation of those points, and the resolution of two land‐cover imagery products from the IGBP‐DISCover Global Land‐Cover Characterization Project (derived from AVHRR data) were assessed and integrated in a GIS. Satellite telemetry is a system where animals are tracked using battery‐operated transmitters and locations are calculated using triangulation from satellites. Using the variable spatial inaccuracy of the telemetry locations, each point was buffered using a radius based on the accuracy of the point, and then intersected with the land cover imagery. The research concluded that the methodology is valuable for studies of birds at a regional scale, with interspecific differences clearly evident, but that diurnal and nocturnal differences were not discernable due to the coarse resolution of both satellite telemetry and land‐cover data. 相似文献
76.
The impact of upland land management on flooding: results from an improved pasture hillslope 总被引:1,自引:0,他引:1
Miles R. Marshall Oliver J. Francis Zoe L. Frogbrook Bethanna M. Jackson Neil McIntyre Brian Reynolds Imogen Solloway Howard S. Wheater Joanne Chell 《水文研究》2009,23(3):464-475
In response to growing concern about impacts of upland agricultural land management on flood risk, an intensely instrumented experimental catchment has been established at Pontbren, a sheep‐farmed headwater catchment of the River Severn, UK. Primary aims are to develop understanding of the processes governing flood generation and the associated impacts of land management practices, and to bridge the gap between process understanding and ability to predict effects on downstream flooding. To achieve this, the experiment is designed to operate at plot (~100 m2), hillslope (~0·1 km2) and small catchment scale (~10 km2). Hillslope‐scale data, from an under‐drained, agriculturally ‘improved’ pasture, show that drain flow is a dominant runoff process. However, depending on antecedent moisture conditions, overland flow may exceed drain flow rates and can be an important contributor to peak flow runoff at the hillslope‐scale. Flow, soil tension data and tracer tests confirm the importance of macropores and presence of perched water tables under ‘normal’ wet conditions. Comparisons of pasture runoff with that from within a 10 year‐old tree shelterbelt show significantly reduced overland flow due to the presence of trees and/or absence of sheep. Comparisons of soil hydraulic properties show significant increases in hydraulic conductivity and saturated moisture content of soil under trees compared to adjacent improved pasture. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
77.
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79.
Helen J. Boon Alison Cottrell David King Robert B. Stevenson Joanne Millar 《Natural Hazards》2012,60(2):381-408
This paper advocates the use of Bronfenbrenner’s bioecological theory as a framework to analyse resilience at diverse scales. Bronfenbrenner’s bioecological theory can be employed to (a) benchmark
social resilience, (b) target the priority interventions required and (c) measure progress arising from these interventions
to enhance resilience to natural disasters. First, the paper explores resilience to natural disasters in the context of climatic
change as building resilience is seen as a way to mitigate impacts of natural disasters. Second, concepts of resilience are
systematically examined and documented, outlining resilience as a trait and resilience as a process. Third, issues arising
in relation to the measurement of resilience are discussed. Fourth, Bronfenbrenner’s bioecological systems theory is described
and proffered to model and assess resilience at different scales. Fifth, studies are described which have supported the use
of the bioecological systems theory for the study of resilience. Sixth, an example of the use of Bronfenbrenner’s theory is
offered and the paper concludes with suggestions for future research using Bronfenbrenner’s theory. 相似文献
80.
David Johnston Sarah Standring Kevin Ronan Michael Lindell Thomas Wilson Jim Cousins Emma Aldridge Michael Warne Ardagh Joanne Margaret Deely Steven Jensen Thomas Kirsch Richard Bissell 《Natural Hazards》2014,73(2):627-637
The aim of this study was to investigate causes of injury during the 2010/2011 Canterbury earthquakes. Data on patients injured during the Darfield (4 September 2010) and Christchurch (22 February 2011) earthquakes were sourced from the New Zealand Accident Compensation Corporation. The total injury burden was analyzed for demography, context of injury, causes of injury, and injury type. Injury context was classified as direct (shaking of the primary earthquake or aftershocks causing unavoidable injuries), action (movement of person during the primary earthquake or aftershocks causing potentially avoidable injuries), and secondary (cause of injury after shaking ceased). Nine categories of injury cause were identified. Three times as many people were injured in the Christchurch earthquake as in the Darfield earthquake (7,171 vs. 2,256). The primary shaking caused approximately two-thirds of the injuries from both quakes. Actions during the primary shaking and aftershocks led to many injuries (51.3 % Darfield and 19.4 % Christchurch). Primary direct caused the highest proportion of injuries during the daytime Christchurch quake (43.6 %). Many people were injured after shaking stopped in both events: 499 (22.1 % Darfield) and 1,881 (26.2 % Christchurch). Most of these people were injured during clean-up (320 (14.2 %) Darfield; 622 (8.7 %) Christchurch). In both earthquakes, more females than males (1,453 vs. 803 Darfield; 4,646 vs. 2,525 Christchurch) were injured (except by masonry, damaged ground, and during clean-up); trip/fall (27.9 % Darfield; 26.1 % Christchurch) was the most common cause of injury; and soft tissue injuries (74.1 % Darfield; 70.4 % Christchurch) was the most common type of injury. This study demonstrated that where people were and their actions during and after earthquakes influenced their risk of injury. 相似文献