Showing papers by "Stockholm University published in 2006"
TL;DR: The resilience perspective is increasingly used as an approach for understanding the dynamics of social-ecological systems as mentioned in this paper, which emphasizes non-linear dynamics, thresholds, uncertainty and surprise, how periods of gradual change interplay with periods of rapid change and how such dynamics interact across temporal and spatial scales.
Abstract: The resilience perspective is increasingly used as an approach for understanding the dynamics of social–ecological systems. This article presents the origin of the resilience perspective and provides an overview of its development to date. With roots in one branch of ecology and the discovery of multiple basins of attraction in ecosystems in the 1960–1970s, it inspired social and environmental scientists to challenge the dominant stable equilibrium view. The resilience approach emphasizes non-linear dynamics, thresholds, uncertainty and surprise, how periods of gradual change interplay with periods of rapid change and how such dynamics interact across temporal and spatial scales. The history was dominated by empirical observations of ecosystem dynamics interpreted in mathematical models, developing into the adaptive management approach for responding to ecosystem change. Serious attempts to integrate the social dimension is currently taking place in resilience work reflected in the large numbers of sciences involved in explorative studies and new discoveries of linked social–ecological systems. Recent advances include understanding of social processes like, social learning and social memory, mental models and knowledge–system integration, visioning and scenario building, leadership, agents and actor groups, social networks, institutional and organizational inertia and change, adaptive capacity, transformability and systems of adaptive governance that allow for management of essential ecosystem services.
4,899 citations
Dalhousie University1, University of Wyoming2, Plymouth Marine Laboratory3, Royal Swedish Academy of Sciences4, Stockholm University5, University of California, Santa Barbara6, Smithsonian Tropical Research Institute7, Scripps Institution of Oceanography8, Stanford University9, University of California, Davis10, University of British Columbia11
TL;DR: The authors analyzed local experiments, long-term regional time series, and global fisheries data to test how biodiversity loss affects marine ecosystem services across temporal and spatial scales, concluding that marine biodiversity loss is increasingly impairing the ocean's capacity to provide food, maintain water quality, and recover from perturbations.
Abstract: Human-dominated marine ecosystems are experiencing accelerating loss of populations and species, with largely unknown consequences. We analyzed local experiments, long-term regional time series, and global fisheries data to test how biodiversity loss affects marine ecosystem services across temporal and spatial scales. Overall, rates of resource collapse increased and recovery potential, stability, and water quality decreased exponentially with declining diversity. Restoration of biodiversity, in contrast, increased productivity fourfold and decreased variability by 21%, on average. We conclude that marine biodiversity loss is increasingly impairing the ocean's capacity to provide food, maintain water quality, and recover from perturbations. Yet available data suggest that at this point, these trends are still reversible.
3,672 citations
TL;DR: In this article, distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS) were presented.
Abstract: We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.
2,273 citations
TL;DR: Transport pathways for PFCAs in the environment were reviewed, and it was concluded that, in addition to atmospheric transport/degradation of precursors, atmospheric and ocean water transport of the PFCA themselves could significantly contribute to their long-range transport.
Abstract: This review describes the sources, fate, and transport of perfluorocarboxylates (PFCAs) in the environment, with a specific focus on perfluorooctanoate (PFO). The global historical industry-wide emissions of total PFCAs from direct (manufacture, use, consumer products) and indirect (PFCA impurities and/or precursors) sources were estimated to be 3200−7300 tonnes. It was estimated that the majority (∼80%) of PFCAs have been released to the environment from fluoropolymer manufacture and use. Although indirect sources were estimated to be much less important than direct sources, there were larger uncertainties associated with the calculations for indirect sources. The physical−chemical properties of PFO (negligible vapor pressure, high solubility in water, and moderate sorption to solids) suggested that PFO would accumulate in surface waters. Estimated mass inventories of PFO in various environmental compartments confirmed that surface waters, especially oceans, contain the majority of PFO. The only environm...
2,035 citations
TL;DR: It is shown that oncogene-induced senescence is associated with signs of DNA replication stress, including prematurely terminated DNA replication forks and DNA double-strand breaks, and, together with apoptosis, provides a barrier to malignant progression.
Abstract: Recent studies have indicated the existence of tumorigenesis barriers that slow or inhibit the progression of preneoplastic lesions to neoplasia. One such barrier involves DNA replication stress, which leads to activation of the DNA damage checkpoint and thereby to apoptosis or cell cycle arrest, whereas a second barrier is mediated by oncogene-induced senescence. The relationship between these two barriers, if any, has not been elucidated. Here we show that oncogene-induced senescence is associated with signs of DNA replication stress, including prematurely terminated DNA replication forks and DNA double-strand breaks. Inhibiting the DNA double-strand break response kinase ataxia telangiectasia mutated (ATM) suppressed the induction of senescence and in a mouse model led to increased tumour size and invasiveness. Analysis of human precancerous lesions further indicated that DNA damage and senescence markers cosegregate closely. Thus, senescence in human preneoplastic lesions is a manifestation of oncogene-induced DNA replication stress and, together with apoptosis, provides a barrier to malignant progression.
1,829 citations
TL;DR: In this paper, a new common stratigraphic timescale for the North Greenland Ice Core Project (NGRIP) and GRIP ice cores is presented, which covers the period 7.9-14.8 kyr before present and includes the Bolling, Allerod, Younger Dryas, and early Holocene periods.
Abstract: [1] We present a new common stratigraphic timescale for the North Greenland Ice Core Project (NGRIP) and GRIP ice cores. The timescale covers the period 7.9–14.8 kyr before present and includes the Bolling, Allerod, Younger Dryas, and early Holocene periods. We use a combination of new and previously published data, the most prominent being new high-resolution Continuous Flow Analysis (CFA) impurity records from the NGRIP ice core. Several investigators have identified and counted annual layers using a multiparameter approach, and the maximum counting error is estimated to be up to 2% in the Holocene part and about 3% for the older parts. These counting error estimates reflect the number of annual layers that were hard to interpret, but not a possible bias in the set of rules used for annual layer identification. As the GRIP and NGRIP ice cores are not optimal for annual layer counting in the middle and late Holocene, the timescale is tied to a prominent volcanic event inside the 8.2 kyr cold event, recently dated in the DYE-3 ice core to 8236 years before A. D. 2000 (b2k) with a maximum counting error of 47 years. The new timescale dates the Younger Dryas-Preboreal transition to 11,703 b2k, which is 100–150 years older than according to the present GRIP and NGRIP timescales. The age of the transition matches the GISP2 timescale within a few years, but viewed over the entire 7.9–14.8 kyr section, there are significant differences between the new timescale and the GISP2 timescale. The transition from the glacial into the Bolling interstadial is dated to 14,692 b2k. The presented timescale is a part of a new Greenland ice core chronology common to the DYE-3, GRIP, and NGRIP ice cores, named the Greenland Ice Core Chronology 2005 (GICC05). The annual layer thicknesses are observed to be log-normally distributed with good approximation, and compared to the early Holocene, the mean accumulation rates in the Younger Dryas and Bolling periods are found to be 47 ± 2% and 88 ± 2%, respectively.
1,789 citations
TL;DR: This paper articulates the understanding of how complex systems change and what determines their ability to absorb disturbances in either their ecological or their social domains and presents a list of some that could help define the next phase of resilience-related research.
Abstract: This paper is a work-in-progress account of ideas and propositions about resilience in socialecological systems. It articulates our understanding of how these complex systems change and what determines their ability to absorb disturbances in either their ecological or their social domains. We call them “propositions” because, although they are useful in helping us understand and compare different social-ecological systems, they are not sufficiently well defined to be considered formal hypotheses. These propositions were developed in two workshops, in 2003 and 2004, in which participants compared the dynamics of 15 case studies in a wide range of regions around the world. The propositions raise many questions, and we present a list of some that could help define the next phase of resilience-related research.
1,268 citations
TL;DR: In this article, the authors draw on the insights from a diverse set of case studies from around the world in which members of the Resilience Alliance have observed or engaged with sustainability problems at regional scales.
Abstract: The sustainability of regional development can be usefully explored through several different lenses. In situations in which uncertainties and change are key features of the ecological landscape and social organization, critical factors for sustainability are resilience, the capacity to cope and adapt, and the conservation of sources of innovation and renewal. However, interventions in social-ecological systems with the aim of altering resilience immediately confront issues of governance. Who decides what should be made resilient to what? For whom is resilience to be managed, and for what purpose? In this paper we draw on the insights from a diverse set of case studies from around the world in which members of the Resilience Alliance have observed or engaged with sustainability problems at regional scales. Our central question is: How do certain attributes of governance function in society to enhance the capacity to manage resilience? Three specific propositions were explored: (1) participation builds trust, and deliberation leads to the shared understanding needed to mobilize and self-organize; (2) polycentric and multilayered institutions improve the fit between knowledge, action, and social-ecological contexts in ways that allow societies to respond more adaptively at appropriate levels; and (3) accountable authorities that also pursue just distributions of benefits and involuntary risks enhance the adaptive capacity of vulnerable groups and society as a whole. Some support was found for parts of all three propositions. In exploring the sustainability of regional social-ecological systems, we are usually faced with a set of ecosystem goods and services that interact with a collection of users with different technologies, interests, and levels of power. In this situation in our roles as analysts, facilitators, change agents, or stakeholders, we not only need to ask: The resilience of what, to what? We must also ask: For whom?
1,265 citations
Book•
19 Jun 2006TL;DR: The goal of this book is to clarify the role of quantum entanglement in the study of convexity, colours and statistics and to show how this role has changed in the history of science.
Abstract: Preface 1 Convexity, colours and statistics 2 Geometry of probability distributions 3 Much ado about spheres 4 Complex projective spaces 5 Outline of quantum mechanics 6 Coherent states and group actions 7 The stellar representation 8 The space of density matrices 9 Purification of mixed quantum states 10 Quantum operations 11 Duality: maps versus states 12 Density matrices and entropies 13 Distinguishability measures 14 Monotone metrics and measures 15 Quantum entanglement Epilogue Appendices References Index
1,139 citations
TL;DR: In this tutorial review recent mechanistic studies on transition metal-catalyzed hydrogen transfer reactions are discussed and an important question is whether the substrate coordinates to the metal (inner-sphere hydrogen transfer) or if there is a direct concerted transfer of hydrogen from the metal to substrate (outer-spheres hydrogen transfer).
Abstract: In this tutorial review recent mechanistic studies on transition metal-catalyzed hydrogen transfer reactions are discussed. A common feature of these reactions is that they involve metal hydrides, which may be monohydrides or dihydrides. An important question is whether the substrate coordinates to the metal (inner-sphere hydrogen transfer) or if there is a direct concerted transfer of hydrogen from the metal to substrate (outer-sphere hydrogen transfer). Both experimental and theoretical studies are reviewed.
958 citations
Space Telescope Science Institute1, University of Leicester2, University of Hertfordshire3, Western Kentucky University4, European Southern Observatory5, University of California, Santa Cruz6, Liverpool John Moores University7, Norwegian Meteorological Institute8, University of Copenhagen9, Spanish National Research Council10, California Institute of Technology11, University of Nottingham12, Stockholm University13, University of Notre Dame14, Vanderbilt University15, Goddard Space Flight Center16, Marshall Space Flight Center17, Renaissance Technologies18, Lawrence Berkeley National Laboratory19, INAF20, University of Amsterdam21
TL;DR: In this article, the authors show that long-duration γ-ray bursts are associated with the most extremely massive stars and may be restricted to galaxies of limited chemical evolution. But they also show that the host galaxies of the long-drone bursts are significantly fainter and more irregular than the hosts of the core-collapse supernovae.
Abstract: When massive stars exhaust their fuel, they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. On occasion, this stellar collapse also powers an even more brilliant relativistic explosion known as a long-duration γ-ray burst. One would then expect that these long γ-ray bursts and core-collapse supernovae should be found in similar galactic environments. Here we show that this expectation is wrong. We find that the γ-ray bursts are far more concentrated in the very brightest regions of their host galaxies than are the core-collapse supernovae. Furthermore, the host galaxies of the long γ-ray bursts are significantly fainter and more irregular than the hosts of the core-collapse supernovae. Together these results suggest that long-duration γ-ray bursts are associated with the most extremely massive stars and may be restricted to galaxies of limited chemical evolution. Our results directly imply that long γ-ray bursts are relatively rare in galaxies such as our own Milky Way.
TL;DR: A twofold increase in the number of crystallization leads was observed when the proteins were cocrystallized with stabilizing additives as compared with experiments without these additives, suggesting that thermofluor constitutes an efficient generic high-throughput method for identification of protein properties predictive of crystallizability.
TL;DR: In this article, the authors investigated whether work engagement (measured by the Utrecht Work Engagement Scale; UWES) could be empirically separated from job involvement and organizational commitment.
Abstract: The present study investigates whether work engagement (measured by the Utrecht Work Engagement Scale; UWES) could be empirically separated from job involvement and organizational commitment. In addition, psychometric properties of the Swedish UWES were investigated. Discriminant validity of the UWES was tested through inspection of latent intercorrelations between the constructs, confirmatory factor analyses, and patterns of correlations with other constructs (health complaints, job and personal factors, and turnover intention) in a sample of Information Communication Technology consultants (N = 186). Conclusion: Work engagement, job involvement, and organizational commitment are empirically distinct constructs and, thus, reflect different aspects of work attachment. The internal consistency of the Swedish UWES was satisfactory, but the dimensionality was somewhat unclear.
TL;DR: The input of BDEs to the Baltic Sea by atmospheric deposition now exceeds that of PCBs by a factor of almost 40 times, and a common suite is suggested which will allow the study of all three commercial PBDE formulations.
TL;DR: In this article, the authors examined the relation between elections and fiscal policy and found evidence of political budget cycles: on average, government fiscal deficit increases by almost 1% of GDP in election years.
TL;DR: The regulation of the mammalian fatty acid elongases and their potential role in lipid metabolism are discussed and both the biochemical functions of the proteins, as well as their role in a more physiological context are considered.
University of Mainz1, University of Delaware2, University of California, Irvine3, University of California, Berkeley4, University of Wuppertal5, Université libre de Bruxelles6, University of Wisconsin-Madison7, Uppsala University8, Stockholm University9, University of Mons-Hainaut10, Lawrence Berkeley National Laboratory11, Pennsylvania State University12, Vrije Universiteit Brussel13, Imperial College London14, University of Wisconsin–River Falls15
TL;DR: In this article, the authors used pulsed and continuous light sources embedded with the AMANDA neutrino telescope, an array of more than six hundred photomultiplier tubes buried deep in the ice.
Abstract: We have remotely mapped optical scattering and absorption in glacial ice at the South Pole for wavelengths between 313 and 560 nm and depths between 1100 and 2350 m. We used pulsed and continuous light sources embedded with the AMANDA neutrino telescope, an array of more than six hundred photomultiplier tubes buried deep in the ice. At depths greater than 1300 m, both the scattering coefficient and absorptivity follow vertical variations in concentration of dust impurities, which are seen in ice cores from other Antarctic sites and which track climatological changes. The scattering coefficient varies by a factor of seven, and absorptivity (for wavelengths less than ∼450 nm) varies by a factor of three in the depth range between 1300 and 2300 m, where four dust peaks due to stadials in the late Pleistocene have been identified. In our absorption data, we also identify a broad peak due to the Last Glacial Maximum around 1300 m. In the scattering data, this peak is partially masked by scattering on residual air bubbles, whose contribution dominates the scattering coefficient in shallower ice but vanishes at ∼1350 m where all bubbles have converted to nonscattering air hydrates. The wavelength dependence of scattering by dust is described by a power law with exponent -0.90 ± 0.03, independent of depth. The wavelength dependence of absorptivity in the studied wavelength range is described by the sum of two components: a power law due to absorption by dust, with exponent -1.08 ± 0.01 and a normalization proportional to dust concentration that varies with depth; and a rising exponential due to intrinsic ice absorption which dominates at wavelengths greater than ∼500 nm. Copyright 2006 by the American Geophysical Union.
Utrecht University1, Yale University2, Rice University3, Purdue University4, Alfred Wegener Institute for Polar and Marine Research5, Stockholm University6, University of Rhode Island7, Brown University8, United States Geological Survey9, University of Bordeaux10, Aix-Marseille University11, Centre national de la recherche scientifique12, Yamagata University13, University College London14, Norwegian Polar Institute15, Boston University16, British Geological Survey17, University of Michigan18, Kyushu University19, University of Southampton20, University of Aberdeen21, University of Padua22, Japan Agency for Marine-Earth Science and Technology23, James Madison University24, University of Tsukuba25, Tohoku University26, National Institute of Advanced Industrial Science and Technology27, Hokkaido University28
TL;DR: It is shown that sea surface temperatures near the North Pole increased from ∼18 °C to over 23°C during this event, which suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds or hurricane-induced ocean mixing—to amplify early Palaeogene polar temperatures.
Abstract: The Palaeocene/Eocene thermal maximum, ~55 million years ago, was a brief period of widespread, extreme climatic warming1, 2, 3, that was associated with massive atmospheric greenhouse gas input4. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition5. We show that sea surface temperatures near the North Pole increased from ~18 °C to over 23 °C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations6, but the absolute polar temperatures that we derive before, during and after the event are more than 10 °C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds7 or hurricane-induced ocean mixing8—to amplify early Palaeogene polar temperatures.
TL;DR: Institutions with broad authority and a global perspective are needed to create a system with incentives for conservation.
Abstract: Marine resource exploitation can deplete stocks faster than regulatory agencies can respond. Institutions with broad authority and a global perspective are needed to create a system with incentives for conservation.
TL;DR: The calibration results suggest that Neoaves, after an initial split from Galloanseres in Mid-Cretaceous, diversified around or soon after the K/T boundary, and show that there is no solid molecular evidence for an extensive pre-Tertiary radiation of Neoaves.
Abstract: Patterns of diversification and timing of evolution within Neoaves, which includes almost 95% of all bird species, are virtually unknown. On the other hand, molecular data consistently indicate a Cretaceous origin of many neoavian lineages and the fossil record seems to support an Early Tertiary diversification. Here, we present the first well-resolved molecular phylogeny for Neoaves, together with divergence time estimates calibrated with a large number of stratigraphically and phylogenetically well-documented fossils. Our study defines several well-supported clades within Neoaves. The calibration results suggest that Neoaves, after an initial split from Galloanseres in Mid-Cretaceous, diversified around or soon after the K/T boundary. Our results thus do not contradict palaeontological data and show that there is no solid molecular evidence for an extensive pre-Tertiary radiation of Neoaves.
TL;DR: The power resources approach, underlining the relevance of socioeconomic class and partisan politics in distributive conflict within capitalist economies, is challenged by employer-centered approaches claiming employers and cross-class alliances to have been crucial in advancing the development of welfare states and varieties of capitalism.
Abstract: The power resources approach, underlining the relevance of socioeconomic class and partisan politics in distributive conflict within capitalist economies, is challenged by employer-centered approaches claiming employers and cross-class alliances to have been crucial in advancing the development of welfare states and varieties of capitalism. Theoretically and empirically these claims are problematic. In welfare state expansion, employers have often been antagonists, under specific conditions consenters, but very rarely protagonists. Well-developed welfare states and coordinated market economies have emerged in countries with strong left parties in long-term cabinet participation or in countries with state corporatist institutional traditions and confessional parties in intensive competition with left parties.
TL;DR: Air and harbor sediment results for PBDEs indicate that there are local sources near highly populated areas within the Arctic and findings of PBBs on moss and TBBPA on an air filter indicates that these compounds may also reach the Arctic by long-range atmospheric transport.
TL;DR: Powsim as mentioned in this paper is a 32-bit Windows/DOS simulation-based computer program that estimates power (and α error) for chi-square and Fisher's exact tests when evaluating the hypothesis of genetic homogeneity.
Abstract: Knowledge of statistical power is essential for sampling design and data evaluation when testing for genetic differentiation. Yet, such information is typically missing in studies of conservation and evolutionary genetics, most likely because of complex interactions between the many factors that affect power. powsim is a 32-bit Windows/DOS simulation-based computer program that estimates power (and α error) for chi-square and Fisher's exact tests when evaluating the hypothesis of genetic homogeneity. Optional combinations include the number of samples, sample sizes, number of loci and alleles, allele frequencies, and degree of differentiation (quantified as FST). powsim is available at http://www.zoologi.su.se/~ryman.
TL;DR: In this paper, the sources, fate, and transport of perfluorocarboxylates (PFCAs) in the environment, with a specific focus on perfluoroctanoate (PFO).
Abstract: This review describes the sources, fate, and transport of perfluorocarboxylates (PFCAs) in the environment, with a specific focus on perfluorooctanoate (PFO). The global historical industry-wide emissions of total PFCAs from direct (manufacture, use, consumer products) and indirect (PFCA impurities and/or precursors) sources were estimated to be 3200−7300 tonnes. It was estimated that the majority (∼80%) of PFCAs have been released to the environment from fluoropolymer manufacture and use. Although indirect sources were estimated to be much less important than direct sources, there were larger uncertainties associated with the calculations for indirect sources. The physical−chemical properties of PFO (negligible vapor pressure, high solubility in water, and moderate sorption to solids) suggested that PFO would accumulate in surface waters. Estimated mass inventories of PFO in various environmental compartments confirmed that surface waters, especially oceans, contain the majority of PFO. The only environm...
TL;DR: Continuous chemical proxy data spanning the last eight glacial cycles from the Dome C Antarctic ice core constrain winter sea-ice extent in the Indian Ocean, Southern Ocean biogenic productivity and Patagonian climatic conditions and observe large glacial–interglacial contrasts in iron deposition, which is infer reflects strongly changing Patagonia conditions.
Abstract: Sea ice and dust flux increased greatly in the Southern Ocean during the last glacial period. Palaeorecords provide contradictory evidence about marine productivity in this region, but beyond one glacial cycle, data were sparse. Here we present continuous chemical proxy data spanning the last eight glacial cycles (740,000 years) from the Dome C Antarctic ice core. These data constrain winter sea-ice extent in the Indian Ocean, Southern Ocean biogenic productivity and Patagonian climatic conditions. We found that maximum sea-ice extent is closely tied to Antarctic temperature on multi-millennial timescales, but less so on shorter timescales. Biological dimethylsulphide emissions south of the polar front seem to have changed little with climate, suggesting that sulphur compounds were not active in climate regulation. We observe large glacial-interglacial contrasts in iron deposition, which we infer reflects strongly changing Patagonian conditions. During glacial terminations, changes in Patagonia apparently preceded sea-ice reduction, indicating that multiple mechanisms may be responsible for different phases of CO2 increase during glacial terminations. We observe no changes in internal climatic feedbacks that could have caused the change in amplitude of Antarctic temperature variations observed 440,000 years ago.
TL;DR: This paper uses four different regions in the world, each of which contains multiple thresholds, to develop a proposed general model of threshold interactions in social-ecological systems, and identifies patch-scale ecological thresholds, farm- or landscape-scale economic thresholds, and regional-scale sociocultural thresholds.
Abstract: Most accounts of thresholds between alternate regimes involve a single, dominant shift defined by one, often slowly changing variable in an ecosystem. This paper expands the focus to include similar dynamics in social and economic systems, in which multiple variables may act together in ways that produce interacting regime shifts in social-ecological systems. We use four different regions in the world, each of which contains multiple thresholds, to develop a proposed general model of threshold interactions in social-ecological systems. The model identifies patch-scale ecological thresholds, farm- or landscape-scale economic thresholds, and regional-scale sociocultural thresholds. Cascading thresholds, i.e., the tendency of the crossing of one threshold to induce the crossing of other thresholds, often lead to very resilient, although often less desirable, alternative states.
University of Rhode Island1, Stockholm University2, Utrecht University3, Brown University4, United States Geological Survey5, Rice University6, University of Bordeaux7, Centre national de la recherche scientifique8, Yamagata University9, University College London10, Norwegian Polar Institute11, Boston University12, British Geological Survey13, University of Michigan14, Kyushu University15, National Oceanography Centre16, University of Aberdeen17, University of Padua18, Japan Agency for Marine-Earth Science and Technology19, James Madison University20, Nagoya University21, Tohoku University22, Hokkaido University23, Leibniz Institute of Marine Sciences24, Paul Scherrer Institute25, University of Bergen26
TL;DR: This record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice and East Antarctic ice and supporting arguments for bipolar symmetry in climate change.
Abstract: The history of the Arctic Ocean during the Cenozoic era (0–65 million years ago) is largely unknown from direct evidence. Here we present a Cenozoic palaeoceanographic record constructed from >400 m of sediment core from a recent drilling expedition to the Lomonosov ridge in the Arctic Ocean. Our record shows a palaeoenvironmental transition from a warm ‘greenhouse’ world, during the late Palaeocene and early Eocene epochs, to a colder ‘icehouse’ world influenced by sea ice and icebergs from the middle Eocene epoch to the present. For the most recent ~14 Myr, we find sedimentation rates of 1–2 cm per thousand years, in stark contrast to the substantially lower rates proposed in earlier studies; this record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice (~3.2 Myr ago) and East Antarctic ice (~14 Myr ago). We find evidence for the first occurrence of ice-rafted debris in the middle Eocene epoch (~45 Myr ago), some 35 Myr earlier than previously thought; fresh surface waters were present at ~49 Myr ago, before the onset of ice-rafted debris. Also, the temperatures of surface waters during the Palaeocene/Eocene thermal maximum (~55 Myr ago) appear to have been substantially warmer than previously estimated. The revised timing of the earliest Arctic cooling events coincides with those from Antarctica, supporting arguments for bipolar symmetry in climate change.
TL;DR: Evidence that black carbon may strongly reduce the risk posed by organic contaminants in sediments and soils is reviewed, implying that current environmental risk assessment systems for these contaminants may be unnecessarily safe.
TL;DR: In this article, the Ecomuseum Kristianstads Vattenrike (EKV) in southern Sweden has identified win-win situations and gained broad support and legitimacy for ecosystem management among a diversity of actors in the region.
Abstract: The literature on ecosystem management and assessment is increasingly focusing on social capacity to enhance ecosystem resilience. Organizational flexibility, participatory approaches to learning, and knowledge generation for responding adequately to environmental change have been highlighted but not critically assessed. The small, flexible municipal organization, Ecomuseum Kristianstads Vattenrike (EKV) in southern Sweden, has identified win-win situations and gained broad support and legitimacy for ecosystem management among a diversity of actors in the region. Navigating the existing legal-political framework, EKV has built a loose social network of local stewards and key persons from organizations at municipal and higher societal levels. As a ‘bridging organization’, EKV has created arenas for trust-building, knowledge generation, collaborative learning, preference formation, and conflicts solving among actors in relation to specific environmental issues. Ad hoc projects are developed as issues arise by mobilizing individuals from the social network. Our results suggest that the EKV approach to adaptive comanagement has enhanced the social capacity to respond to unpredictable change and developed a trajectory towards resilience of a desirable social-ecological system.