1,339 research outputs found

    Transitions of social-ecological subsistence systems in the Arctic

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    Transitions of social-ecological systems (SES) expose governance systems to new challenges. This is particularly so in the Arctic where resource systems are increasingly subjected to global warming, industrial development and globalization which subsequently alter the local SES dynamics. Based on common-pool resource theory, we developed a dynamic conceptual model explaining how exogenous drivers might alter a traditional subsistence system from a provisioning to an appropriation actions situation. In a provisioning action situation the resource users do not control the resource level but adapt to the fluctuating availability of resources, and the collective challenge revolve around securing the subsistence in the community. An increased harvest pressure enabled by exogenous drivers could transform the SES to an appropriation action situation where the collective challenge has changed to avoid overuse of a common-pool resource. The model was used as a focal lens to investigate the premises for broad-scale transitions of subsistence-oriented SESs in Arctic Alaska, Canada and Greenland. We synthesized data from documents, official statistics and grey and scientific literature to explore the different components of our model. Our synthesis suggests that the traditional Arctic subsistence SESs mostly comply with a provisioning action situation. Despite population growth and available technology; urbanization, increased wage labor and importation of food have reduced the resource demand, and we find no evidence for a broad-scale transition to an appropriation action situation throughout the Western Arctic. However, appropriation challenges have emerged in some cases either as a consequence of commercialization of the resource or by severely reduced resource stocks due to various exogenous drivers. Future transitions of SESs could be triggered by the emergence of commercial local food markets and Arctic warming. In particular, Arctic warming is an intensifying exogenous driver that is threatening many important Arctic wildlife resources inflicting increased appropriation challenges to the governance of local harvest.Ye

    Backlash and State Strategies in International Investment Law

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    This book provides an important corrective to existing theories of international law by focusing on how states respond to increased legalisation and rely on legal expertise to manoeuvre within and against international law

    Environmental variation as a driver of predator-prey interactions

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    Animals often face the trade-off of optimizing foraging while limiting predation. In variable and seasonal environments the availability of resources changes spatially and temporally, forcing animals to adapt their spatial foraging patterns over time and, thus, to modify their exposure to predation. Previous research has mostly dealt with the causes and consequences of animal spatial patterns separately, with studies either examining how changes in the environment influence habitat selection, or determining the effects of habitat use on vulnerability to predation. Here we combine these aspects through an examination of how weather conditions affect predation risk by modifying the spatial behavior of the prey. We used reindeer calves (Rangifer tarandus) in Norway to investigate (1) the environmental causes and (2) the survival consequences of habitat use. We further examined how those relationships varied temporally and according to the body mass of calves. We found that deep snow and ice conditions led reindeer to shift from their usually preferred high-elevation pastures to lowland forested areas. This increase in forest use was associated with lower calf survival, mostly due to elevated lynx (Lynx lynx) predation rates. Golden eagles (Aquila chrysaetos) and wolverines (Gulo gulo) also preyed on calves but their effect was much smaller and not associated with a specific habitat type. The link between climatic conditions, habitat use, and predation changed over the winter season and depended on the body weights of the calves. The effect of harsh weather conditions on reindeer use of forested habitats was stronger towards the end of the winter, which coincides with more deteriorated body conditions and lower food availability on high-elevation pastures, and predation probabilities were higher for smaller individuals. Our study demonstrates that environmental variation importantly affects predator-prey interactions. Key words: ecological trade-off; habitat use; Norwegian semidomestic reindeer; predation rates; predator-prey dynamics; Rangifer tarandus; seasonal environments; ungulate foraging ecology; weather variability.publishedVersio

    Scale-dependent response diversity of seabirds to prey in the North Sea

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    Functional response diversity is defined as the diversity of responses to environmental change among species that contribute to the same ecosystem function. Because different ecological processes dominate on different spatial and temporal scales, response diversity is likely to be scale dependent. Using three extensive data sets on seabirds, pelagic fish, and zooplankton, we investigate the strength and diversity in the response of seabirds to prey in the North Sea over three scales of ecological organization. Two-stage analyses were used to partition the variance in the abundance of predators and prey among the different scales of investigation: variation from year to year, variation among habitats, and variation on the local patch scale. On the year-to-year scale, we found a strong and synchronous response of seabirds to the abundance of prey, resulting in low response diversity. Conversely, as different seabird species were found in habitats dominated by different prey species, we found a high diversity in the response of seabirds to prey on the habitat scale. Finally, on the local patch scale, seabirds were organized in multispecies patches. These patches were weakly associated with patches of prey, resulting in a weak response strength and a low response diversity. We suggest that ecological similarities among seabird species resulted in low response diversity on the year-to-year scale. On the habitat scale, we suggest that high response diversity was due to interspecific competition and niche segregation among seabird species. On the local patch scale, we suggest that facilitation with respect to the detection and accessibility of prey patches resulted in overlapping distribution of seabirds but weak associations with prey. The observed scale dependencies in response strength and diversity have implications for how the seabird community will respond to different environmental disturbances

    Efficient Sampling for Ecosystem Service Supply Assessment at a Landscape Scale

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    Decision makers and stakeholders need high-quality data to manage ecosystem services (ES) efficiently. Landscape-level data on ES that are of sufficient quality to identify spatial tradeoffs, co-occurrence and hotspots of ES are costly to collect, and it is therefore important to increase the efficiency of sampling of primary data. We demonstrate how ES could be assessed more efficiently through image-based point intercept method and determine the tradeoff between the number of sample points (pins) used per image and the robustness of the measurements. We performed a permutation study to assess the reliability implications of reducing the number of pins per image. We present a flexible approach to optimize landscape-level assessments of ES that maximizes the information obtained from 1 m2 digital images. Our results show that 30 pins are sufficient to measure ecosystem service indicators with a crown cover higher than 5% for landscape scale assessments. Reducing the number of pins from 100 to 30 reduces the processing time up to a 50% allowing to increase the number of sampled plots, resulting in more management-relevant ecosystem service maps. The three criteria presented here provide a flexible approach for optimal design of landscape-level assessments of ES

    Poleward shifts in marine fisheries under Arctic warming

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    As global warming makes the Arctic Ocean more accessible, concerns have been raised about the environmental consequences of a possible expansion of commercial fisheries into pristine marine ecosystems. Using a recently released global dataset, we quantify for the first time how fishing activities are responding to diminishing sea ice and a warmer Arctic Ocean. We show that trawling dominates Arctic fisheries and that this activity penetrates rapidly into Arctic shelf areas previously protected by extensive ice-cover as a response to interannual sea ice loss. We model the development of trawling activity under a climate change scenario and use the model to identify areas with high risk of increased trawling activity and estimate the amount of trawling avoided in recently established fishery protection zones. Stronger responsibility must be undertaken by Arctic coastal states to regulate increased fishing pressure and protect vulnerable Arctic shelf ecosystems.publishedVersio

    Seafood production in Northern Norway: Analyzing variation and co-development in aquaculture and coastal fisheries

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    Norway is one of the leading ocean-based food production nations. Its seafood industry comprises wild-capture fisheries and farmed fish production. Both industries play a provisional role but also contribute to economic development of the country and help sustain coastal communities, particularly, in Northern Norway. Coastal fishery has been the staple industry in Northern Norway for centuries, while aquaculture complemented the seafood production in this region only approximately 40 years ago. To date, there has been limited knowledge on how the two industries co-developed in Northern Norway. While there are controversies regarding the potential cost and benefit of aquaculture to local communities, only a few studies have addressed co-existence of the two seafood industries in Northern Norway on a municipality scale. In this study, we compared the development of coastal fisheries and aquaculture in Northern Norway over a 14-year period (2005–2018) using a Bayesian approach that allowed to fit a model specific to each municipality, accounting also for temporal changes in both industries. A strong stochastic spatial variation characterized both industries, indicating a sizeable gap in the seafood production between the municipalities. Finally, the study showed that the fisheries and aquaculture likely did not affect each other’s production, suggesting that there were no or few discernible conflicts or synergies between these two industries in Northern Norway. This study featured an advanced method for analyzing variation of seafood production per administrative unit that can be transferable to assess seafood development in other regions of Norway and beyond

    Renal transplantation in patients 65 years old or older.

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    Between January 1982 and August 1989, cadaveric renal transplantation was performed in 22 patients 65 years old or older. Mean recipient age was 68 years (range 65 to 73 years). There were 17 men and 5 women. Additional risk factors included retransplantation (3 patients), high (greater than 30%) panel reactive antibody (4) and diabetes (1). All patients received cyclosporine as part of the immunosuppressive regimen. The 3-year actuarial patient and allograft survival rates were 89% and 71%, respectively. There were 6 graft losses due to chronic rejection (2 patients), renal vein thrombosis (1), myocardial infarction (1), withdrawal of immunosuppression because of sepsis (1) and primary nonfunction (1). Of the 16 patients with a functioning graft 12 currently have a serum creatinine of less than 2.0 mg./dl. These results suggest that cadaveric renal transplantation is an acceptable form of treatment for patients older than 65 years with end stage renal disease
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