Separation of allelopathy and resource competition by the boreal dwarf shrub Empetrum hermaphroditum Hagerup

Oecologia ◽  
1994 ◽  
Vol 98 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Marie-Charlotte Nilsson
Keyword(s):  
Resource Competition ◽  
Dwarf Shrub ◽  
Empetrum Hermaphroditum

Ring-Width Chronologies of the Alpine Dwarf Shrub Empetrum Hermaphroditum FROM THE NORWEGIAN MOUNTAINS

IAWA Journal ◽  
2007 ◽  
Vol 28 (3) ◽  
pp. 325-338 ◽  
Author(s):  
Annette Bär ◽  
Achim Bräuning ◽  
Jörg Löffler
Keyword(s):  
Ring Width ◽  
Growth Curves ◽  
Growth Period ◽  
Snow Accumulation ◽  
Growth Patterns ◽  
Dwarf Shrub ◽  
Tree Line ◽  
Growth Variability ◽  
Empetrum Hermaphroditum ◽  
Growth Increments

In this study, we present the first ring-width chronologies of the dwarf shrub species Empetrum hermaphroditum. For a proper synchronization of the growth rings, serial sectioning was applied in order to deal with the high intern al growth variability and the high proportion of discontinuous rings. The plants were collected from three micro-sites in the middle alpine belt of the Norwegian Scandes wh ich differed regarding solar insolation, snow accumulation and wind exposure. The constructed ringwidth chronologies cover aperiod of max. 80 years. Irrespective of microclimatic differences, the chronologies are highly correlated among each other and with temperatures during the growth period (June-August). However, ecological differences between the micro-sites are reflected by the mean annual growth increments of the plants. We compared the Empetrum chronologies with a ring-width chronology of Betula pubescens trees from the local tree line. Despite the differences in life form and local site conditions, the growth patterns are very similar, an observation which underscores the dominant influence of temperature on growthring formation. Due to the strong climatic signal recorded in the growth curves of E. hermaphroditum, this dwarf shrub provides a significant potential for climate-growth studies in arctic and alpine regions beyond the tree line.

scholarly journals Clonality increases with snow depth in the arctic dwarf shrub Empetrum hermaphroditum

2016 ◽  
Vol 103 (12) ◽  
pp. 2105-2114 ◽  
Author(s):  
Miriam J. Bienau ◽  
R. Lutz Eckstein ◽  
Annette Otte ◽  
Walter Durka
Keyword(s):  
Snow Depth ◽  
Dwarf Shrub ◽  
The Arctic ◽  
Empetrum Hermaphroditum

Potential Toxic Effect on Aquatic Fauna by the Dwarf Shrub Empetrum hermaphroditum

2004 ◽  
Vol 30 (1) ◽  
pp. 215-227 ◽  
Author(s):  
Eva Brännäs, ◽  
Marie-Charlotte Nilsson ◽  
Linda Nilsson ◽  
Christiane Gallet ◽  
Kurt Brännäs ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Dwarf Shrub ◽  
Aquatic Fauna ◽  
Empetrum Hermaphroditum

China and the Geopolitics of Rare Earths

2017 ◽  
Author(s):  
Sophia Kalantzakos
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Resource Competition ◽  
Renewable Energy Sources ◽  
High Tech ◽  
Trade Dispute ◽  
Policy Responses ◽  
Economic Statecraft ◽  
The Rare Earth

In 2010, because of a geopolitical incident between China and Japan, seventeen elements of the periodic table known as rare earths became notorious overnight. An “unofficial” and temporary embargo of rare-earth shipments to Japan alerted the world to China’s near monopoly position on the production and export of these indispensable elements for high-tech, defense, and renewable energy sources. A few months before the geopolitical confrontation, China had chosen to substantially cut export quotas of rare earths. Both events sent shockwaves across the markets, and rare-earth prices skyrocketed, prompting reactions from industrial nations and industry itself. The rare-earth crisis is not a simple trade dispute, however. It also raises questions about China’s use of economic statecraft and the impacts of growing resource competition. A detailed and nuanced examination of the rare-earth crisis provides a significant and distinctive case study of resource competition and its spill-over geopolitical effects. It sheds light on the formulation, deployment, longevity, effectiveness, and, perhaps, shortsightedness of policy responses by other industrial nations, while also providing an example of how China might choose to employ instruments of economic statecraft in its rise to superpower status.

scholarly journals Managing sustainability risks of bioenergy in four Nordic countries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anders Chr. Hansen ◽  
Nicholas Clarke ◽  
Atle Wehn Hegnes
Keyword(s):  
Resource Competition ◽  
Local Level ◽  
Stakeholder Involvement ◽  
Local Communities ◽  
Carbon Pools ◽  
Energy Technologies ◽  
Agents Of Change ◽  
Local Actors ◽  
Government Planning ◽  
High Degree

Abstract Background Bioenergy plays a key role in the transition to a sustainable economy in Europe, but its own sustainability is being questioned. We study the experiences of Sweden, Finland, Denmark and Norway, to find out whether the forest-based bioenergy chains developed in the four countries have led to unsustainable outcomes and how the countries manage the sustainability risks. Data were collected from a diversity of sources including interviews, statistical databases, the scientific literature, government planning documents and legislation. Results Sustainability risks of deforestation, degradation of forests, reduced carbon pools in forests, expensive biopower and heat, resource competition, and lack of acceptance at the local level are considered. The experience of the four countries shows that the sustainability risks can to a high degree be managed with voluntary measures without resorting to prescriptive measures. It is possible to add to the carbon pools of forests along with higher harvest volumes if the risks are well managed. There is, however, a marginal trade-off between harvest volume and carbon pools. Economic sustainability risks may be more challenging than ecological risks because the competitiveness order of renewable energy technologies has been reversed in the last decade. The risk of resource competition harming other sectors in the economy was found to be small and manageable but requires continuous monitoring. Local communities acting as bioenergy communities have been agents of change behind the most expansive bioenergy chains. A fear of non-local actors reaping the economic gains involved in bioenergy chains was found to be one of the risks to the trust and acceptance necessary for local communities to act as bioenergy communities. Conclusions The Nordic experience shows that it has been possible to manage the sustainability risks examined in this paper to an extent avoiding unsustainable outcomes. Sustainability risks have been managed by developing an institutional framework involving laws, regulations, standards and community commitments. Particularly on the local level, bioenergy chains should be developed with stakeholder involvement in development and use, in order to safeguard the legitimacy of bioenergy development and reconcile tensions between the global quest for a climate neutral economy and the local quest for an economically viable community.

scholarly journals Stability and Robustness of Unbalanced Genetic Toggle Switches in the Presence of Scarce Resources

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 271
Author(s):  
Chentao Yong ◽  
Andras Gyorgy
Keyword(s):  
Cell Fate ◽  
Rational Design ◽  
Resource Competition ◽  
Dynamic Properties ◽  
Mechanistic Model ◽  
Robustness Analysis ◽  
System Level ◽  
Genetic Circuits ◽  
Scarce Resources ◽  
Genetic Systems

While the vision of synthetic biology is to create complex genetic systems in a rational fashion, system-level behaviors are often perplexing due to the context-dependent dynamics of modules. One major source of context-dependence emerges due to the limited availability of shared resources, coupling the behavior of disconnected components. Motivated by the ubiquitous role of toggle switches in genetic circuits ranging from controlling cell fate differentiation to optimizing cellular performance, here we reveal how their fundamental dynamic properties are affected by competition for scarce resources. Combining a mechanistic model with nullcline-based stability analysis and potential landscape-based robustness analysis, we uncover not only the detrimental impacts of resource competition, but also how the unbalancedness of the switch further exacerbates them. While in general both of these factors undermine the performance of the switch (by pushing the dynamics toward monostability and increased sensitivity to noise), we also demonstrate that some of the unwanted effects can be alleviated by strategically optimized resource competition. Our results provide explicit guidelines for the context-aware rational design of toggle switches to mitigate our reliance on lengthy and expensive trial-and-error processes, and can be seamlessly integrated into the computer-aided synthesis of complex genetic systems.

scholarly journals Does Local Adaptation Impact on the Distribution of Competing Aedes Disease Vectors?

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Kelly L. Bennett ◽  
William Owen McMillan ◽  
Jose R. Loaiza
Keyword(s):  
Local Adaptation ◽  
Resource Competition ◽  
Disease Vectors ◽  
Human Populations ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Climate Conditions ◽  
Ecological Resources ◽  
The Face ◽  
Arboviral Disease

Ae. (Stegomyia) aegypti L. and Aedes (Stegomyia) albopictus Skuse mosquitoes are major arboviral disease vectors in human populations. Interspecific competition between these species shapes their distribution and hence the incidence of disease. While Ae. albopictus is considered a superior competitor for ecological resources and displaces its contender Ae. aegypti from most environments, the latter is able to persist with Ae. albopictus under particular environmental conditions, suggesting species occurrence cannot be explained by resource competition alone. The environment is an important determinant of species displacement or coexistence, although the factors underpinning its role remain little understood. In addition, it has been found that Ae. aegypti can be adapted to the environment across a local scale. Based on data from the Neotropical country of Panama, we present the hypothesis that local adaptation to the environment is critical in determining the persistence of Ae. aegypti in the face of its direct competitor Ae. albopictus. We show that although Ae. albopictus has displaced Ae. aegypti in some areas of Panama, both species coexist across many areas, including regions where Ae. aegypti appear to be locally adapted to dry climate conditions and less vegetated environments. Based on these findings, we describe a reciprocal transplant experiment to test our hypothesis, with findings expected to provide fundamental insights into the role of environmental variation in shaping the landscape of emerging arboviral disease.

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