| 1. |
- Bennett, Elena M., et al.
(författare)
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Bright spots : seeds of a good Anthropocene
- 2016
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Ingår i: Frontiers in Ecology and the Environment. - : Wiley. - 1540-9295 .- 1540-9309. ; 14:8, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- The scale, rate, and intensity of humans' environmental impact has engendered broad discussion about how to find plausible pathways of development that hold the most promise for fostering a better future in the Anthropocene. However, the dominance of dystopian visions of irreversible environmental degradation and societal collapse, along with overly optimistic utopias and business-as-usual scenarios that lack insight and innovation, frustrate progress. Here, we present a novel approach to thinking about the future that builds on experiences drawn from a diversity of practices, worldviews, values, and regions that could accelerate the adoption of pathways to transformative change (change that goes beyond incremental improvements). Using an analysis of 100 initiatives, or seeds of a good Anthropocene, we find that emphasizing hopeful elements of existing practice offers the opportunity to: (1) understand the values and features that constitute a good Anthropocene, (2) determine the processes that lead to the emergence and growth of initiatives that fundamentally change human-environmental relationships, and (3) generate creative, bottom-up scenarios that feature well-articulated pathways toward a more positive future.
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| 2. |
- Gilbert, F., et al.
(författare)
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Sediment reworking by the burrowing polychaete Hediste diversicolor modulated by environmental and biological factors across the temperate North Atlantic. A tribute to Gaston Desrosiers
- 2021
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981. ; 541
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Tidskriftsartikel (refereegranskat)abstract
- Particle mixing and irrigation of the seabed by benthic fauna (bioturbation) have major impacts on ecosystem functions such as remineralization of organic matter and sediment-water exchange. As a tribute to Prof. Gaston Desrosiers by the Nereis Park association, eighteen laboratories carried out a collaborative experiment to acquire a global snapshot of particle reworking by the polychaete Hediste diversicolor at 16 sites surrounding the Northern Atlantic. Organisms and soft sediments were collected during May - July at different geographical locations and, using a common laboratory protocol, particulate fluorescent tracers (`luminophores') were used to quantify particle transport over a 10-day period. Particle mixing was quantified using the maximum penetration depth of tracers (MPD), particle diffusive coefficients (D-b), and non-local transport coefficients (r). Non-local coefficients (reflecting centimeter scale transport steps) ranged from 0.4 to 15 yr(-1), and were not correlated across sites with any measured biological (biomass, biovolume) or environmental parameters (temperature, grain size, organic matter). Maximum penetration depths (MPD) averaged similar to 10.7 cm (6.5-14.5 cm), and were similar to the global average bioturbation depth inferred from short-lived radiochemical tracers. MPD was also not correlated with measures of size (individual biomass), but increased with grain size and decreased with temperature. Bio-diffusion (D-b) correlated inversely with individual biomass (size) and directly with temperature over the environmental range (Q(10) similar to 1.7; 5-21 degrees C). The transport data were comparable in magnitude to rates reported for localized H. diversicolor populations of similar size, and confirmed some but not all correlations between sediment reworking and biological and environmental variables found in previous studies. The results imply that measures of particle reworking activities of a species from a single location can be generally extrapolated to different populations at similar conditions.
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| 3. |
- Hudson, I. R., et al.
(författare)
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Feeding behaviour of deep-sea dwelling holothurians: Inferences from a laboratory investigation of shallow fjordic species
- 2005
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Ingår i: Journal of Marine Systems. - : Elsevier BV. - 0924-7963. ; 57:3-4, s. 201-218
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Tidskriftsartikel (refereegranskat)abstract
- An experimental mesocosm was used to investigate the feeding behaviour, particle size selectivity gut throughput time and dietary selection of two holothurian species, Stichopus tremulus (Gunnerus) and Mesothuria intestinalis (Ascanius). Specimens usually only present at depths >1000m in the North-eastern Atlantic Ocean were collected from a relatively shallow (<100 m) cold-water fjordic system in Sweden and maintained in the laboratory. Both species exhibited a similar strategy for retrieving sediment particles from the sediment surface; feeding tentacles were used in a 'grasping' motion to pick up sediment particles. The rate at which the feeding tentacles were placed onto the sediment surface, however, differed between species (S. tremulus was three times quicker than M. intestinalis) resulting in a significant difference in gut throughput time. Both species, when offered different sized sediment particles, showed a preference for finer sediment and for nutritionally rich, pigment-enhanced, food patches. (c) 2005 Elsevier B.V. All rights reserved.
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| 4. |
- Mace, Georgina M., et al.
(författare)
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Approaches to defining a planetary boundary for biodiversity
- 2014
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Ingår i: Global Environmental Change. - : Elsevier BV. - 0959-3780 .- 1872-9495. ; 28, s. 289-297
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Tidskriftsartikel (refereegranskat)abstract
- The idea that there is an identifiable set of boundaries, beyond which anthropogenic change will put the Earth system outside a safe operating space for humanity, is attracting interest in the scientific community and gaining support in the environmental policy world. Rockstrom et al. (2009) identify nine such boundaries and highlight biodiversity loss as being the single boundary where current rates of extinction put the Earth system furthest outside the safe operating space. Here we review the evidence to support a boundary based on extinction rates and identify weaknesses with this metric and its bearing on humanity's needs. While changes to biodiversity are of undisputed importance, we show that both extinction rate and species richness are weak metrics for this purpose, and they do not scale well from local to regional or global levels. We develop alternative approaches to determine biodiversity loss boundaries and extend our analysis to consider large-scale responses in the Earth system that could affect its suitability for complex human societies which in turn are mediated by the biosphere. We suggest three facets of biodiversity on which a boundary could be based: the genetic library of life; functional type diversity; and biome condition and extent. For each of these we explore the science needed to indicate how it might be measured and how changes would affect human societies. In addition to these three facets, we show how biodiversity's role in supporting a safe operating space for humanity may lie primarily in its interactions with other boundaries, suggesting an immediate area of focus for scientists and policymakers.
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| 5. |
- Solan, M., et al.
(författare)
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In situ quantification of bioturbation using time-lapse fluorescent sediment profile imaging (f-SPI), luminophore tracers and model simulation
- 2004
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Ingår i: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 271, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- In order to link actual biological data on bioturbation to the abstract parameters in bioturbation models, high-resolution data on the frequency and lengths of particle displacements are required. The temporal variation in bioturbation for a subtidal macrofaunal assemblage was studied non-invasively and in situ using an optically modified fluorescence sensitive time-lapse sediment profile imaging camera (f-SPI), fluorescent-dyed sediment particles (luminophores) and mathematical modelling. This combined approach allowed tracer particles to be non-invasively tracked and their displacements monitored at an unprecedented spatial (78 mum) and temporal (every 10 min) resolution for extended periods of time (16 h). The redistribution of luminophores was digitally acquired from sequential images and compared to model predictions, with particle transport modelled as (1) a diffusive process, allowing the biodiffusion coefficient, D-b, to be estimated, and (2) a non-local process, allowing a reworking activity constant, a, to be calculated. Model predictions of luminophore particle transport for the final image of the f-SPI sequence gave: D-b = 1.26 x 10(2) cm(2) yr(-1); a = 5.23 x 10(-2) cm(-1) yr(-1). Discrete values of a fluctuated widely throughout the sequence and allowed discrete bioturbation events to be identified. Time-lapse movie sequences revealed that most of the bioturbation observed during the deployment could be directly attributed to the behaviour of the brachyuran crab Hyas araneus. Our findings demonstrate that f-SPI provides a rapid and non-invasive means to visualise and quantify, in situ, the extent and influence of discrete infaunal bioturbation events on particle mixing. This technique provides detailed information on the spatial and temporal resolution of such bioturbation events, which could significantly improve existing models of bioturbation.
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| 6. |
- Solan, M., et al.
(författare)
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Towards a greater understanding of pattern, scale and process in marine benthic systems: a picture is worth a thousand worms
- 2003
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Ingår i: Journal of Experimental Marine Biology and Ecology. - 0022-0981. ; 285, s. 313-338
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Tidskriftsartikel (refereegranskat)abstract
- Historically, advances in our knowledge of benthic community structure and functioning have necessarily relied upon destructive sampling devices (grabs, cores, anchor dredges, etc.) that lose valuable contextual information in the process of sampling. In the last 40 years, instrumentation capable of measuring dynamic events and/or processes within and immediately above the seafloor has been developed that facilitates the collection of ecological information. Of these, both acoustic and optical imaging devices have played a significant role in revealing much about the physiology and behaviour of, and interactions between benthic species, and the sedimentary habitat in which they reside. While a number of reviews have separately considered the methodological and technical aspects of imaging technologies, the collective contribution that imaging has made to benthic ecology has received less attention. In this short review, we attempt to highlight key instances over the last 40 years where either acoustic or optical-based imaging techniques have provided new ecological insights and information about fine-grained sedimentary environments. In so doing, we focus on the ecological advances that have formed the precursor to current research efforts and introduce some of the latest revelations from appropriate and emerging imaging applications. (C) 2002 Elsevier Science B.V. All rights reserved.
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