High-altitude forest sensitivity to global warming: results from long-term and short-term analyses in the eastern italian alps

2005 ◽  
pp. 171-189 ◽  
Author(s):  
Marco Carrer ◽  
Tommaso Anfodillo ◽  
Carlo Urbinati ◽  
Vinicio Carraro
Keyword(s):  
Global Warming ◽  
High Altitude ◽  
Italian Alps ◽  
Short Term

scholarly journals Metabolic plasticity can amplify ecosystem responses to global warming

2021 ◽  
Author(s):  
Rebecca Kordas ◽  
Samraat Pawar ◽  
Guy Woodward ◽  
Eoin O'Gorman
Keyword(s):  
Global Warming ◽  
Body Size ◽  
Predictive Models ◽  
Chronic Exposure ◽  
Ecosystem Respiration ◽  
Short Term ◽  
Ecosystem Responses ◽  
Metabolic Plasticity ◽  
Ecosystem Level

Abstract Organisms have the capacity to alter their physiological response to warming through acclimation or adaptation, but empirical evidence for this metabolic plasticity across species within food webs is lacking, and a generalisable framework does not exist for modelling its ecosystem-level consequences. Here we show that the ability of organisms to raise their metabolic rate following chronic exposure to warming decreases with increasing body size. Chronic exposure to higher temperatures also increases the sensitivity of organisms to short-term warming, irrespective of their body size. A mathematical model parameterised with these findings shows that metabolic plasticity could account for an additional 60% of ecosystem energy flux with just +2 °C of warming. This could explain why ecosystem respiration continues to rise in long-term warming experiments and highlights the need to embed metabolic plasticity in predictive models of global warming impacts on ecosystems.

Adaptations to High-Altitude Hypoxia

2021 ◽  
Author(s):  
Cynthia M. Beall ◽  
Kingman P. Strohl
Keyword(s):  
High Altitude ◽  
Oxygen Delivery ◽  
Hemoglobin Concentration ◽  
Barometric Pressure ◽  
Ambient Air ◽  
Extreme Environment ◽  
Indigenous Populations ◽  
East African ◽  
Short Term

Biological anthropologists aim to explain the hows and whys of human biological variation using the concepts of evolution and adaptation. High-altitude environments provide informative natural laboratories with the unique stress of hypobaric hypoxia, which is less than usual oxygen in the ambient air arising from lower barometric pressure. Indigenous populations have adapted biologically to their extreme environment with acclimatization, developmental adaptation, and genetic adaptation. People have used the East African and Tibetan Plateaus above 3,000 m for at least 30,000 years and the Andean Plateau for at least 12,000 years. Ancient DNA shows evidence that the ancestors of modern highlanders have used all three high-altitude areas for at least 3,000 years. It is necessary to examine the differences in biological processes involved in oxygen exchange, transport, and use among these populations. Such an approach compares oxygen delivery traits reported for East African Amhara, Tibetans, and Andean highlanders with one another and with short-term visitors and long-term upward migrants in the early or later stages of acclimatization to hypoxia. Tibetan and Andean highlanders provide most of the data and differ quantitatively in biological characteristics. The best supported difference is the unelevated hemoglobin concentration of Tibetans and Amhara compared with Andean highlanders as well as short- and long-term upward migrants. Moreover, among Tibetans, several features of oxygen transfer and oxygen delivery resemble those of short-term acclimatization, while several features of Andean highlanders resemble the long-term responses. Genes and molecules of the oxygen homeostasis pathways contribute to some of the differences.

HISTORY, POLITICS, AND CLAIMS OF MAN-MADE GLOBAL WARMING

2009 ◽  
Vol 26 (2) ◽  
pp. 231-271
Author(s):  
John David Lewis
Keyword(s):  
Global Warming ◽  
Environmental Protection Agency ◽  
Fossil Fuels ◽  
Global Scale ◽  
The Political ◽  
Economic Decline ◽  
Protection Agency ◽  
Short Term ◽  
Scientific Support

Claims that a man-made global warming catastrophe is imminent have two major aspects: the scientific support offered for the claims, and the political proposals brought forth in response to the claims. The central questions are whether non-scientists should accept the claims themselves as true, and whether they should support the political proposals attached to them. Predictions of a coming disaster are shown to be a-historical in both the long term and the short term, to involve shifting predictions that are contrary to evidence, and to be opposed by many scientists. The political proposals to alleviate this alleged problem—especially plans by the U.S. Environmental Protection Agency—are shown to offer no alternative to fossil fuels, and to portend a major economic decline and permanent losses of liberty. The anthropogenic global warming claims are largely motivated not by science, but by a desire for socialist intervention on a national and a global scale. Neither the claims to an impending climate catastrophe nor the political proposals attached to those claims should be accepted.

scholarly journals On the Identification and Characterization of Drought and Aridity in Postglacial Paleoenvironmental Records from the Northern Great Plains

2004 ◽  
Vol 56 (2-3) ◽  
pp. 229-246 ◽  
Author(s):  
Alwynne B. Beaudoin
Keyword(s):  
Global Warming ◽  
High Resolution ◽  
Great Plains ◽  
Northern Great Plains ◽  
Short Term ◽  
Instrumental Data ◽  
Proxy Records ◽  
Identification And Characterization

Abstract The Northern Great Plains region is especially sensitive to drought and is likely to be even more drought-prone under projected global warming. Drought has been invoked as an explanatory factor for changes seen in postglacial paleoenvironmental records. These proxy records may extend drought history derived from instrumental data. Moreover, in the last decade, some paleoenvironmental studies have been expressly undertaken for the examination of long-term drought history. Nevertheless, few such studies explicitly define drought. This makes it difficult to compare results or to understand what the results mean in terms of the operational drought definitions that are used in resource management. Operational drought is defined as usually short-term; longer sustained dry intervals reflect a shift to aridity. Therefore, high resolution paleoenvironmental proxies (annual or subdecadal) are best for the investigation of drought history. Such proxies include tree rings and some lake records. However, most lake-based records are sampled at lower resolution (decadal or subcentury) and are therefore providing aridity signals.

scholarly journals Technical note: On comparing greenhouse gas emission metrics

2021 ◽  
Vol 21 (6) ◽  
pp. 4699-4708
Author(s):  
Ian Enting ◽  
Nathan Clisby
Keyword(s):  
Global Warming ◽  
Greenhouse Gas ◽  
Global Warming Potential ◽  
Radiative Forcing ◽  
Greenhouse Gas Emission ◽  
Technical Note ◽  
Short Term ◽  
Rates Of Change

Abstract. Many metrics for comparing greenhouse gas emissions can be expressed as an instantaneous global warming potential multiplied by the ratio of airborne fractions calculated in various ways. The forcing equivalent index (FEI) provides a specification for equal radiative forcing at all times at the expense of generally precluding point-by-point equivalence over time. The FEI can be expressed in terms of asymptotic airborne fractions for exponentially growing emissions. This provides a reference against which other metrics can be compared. Four other equivalence metrics are evaluated in terms of how closely they match the timescale dependence of FEI, with methane referenced to carbon dioxide used as an example. The 100-year global warming potential overestimates the long-term role of methane, while metrics based on rates of change overestimate the short-term contribution. A recently proposed metric based on differences between methane emissions 20 years apart provides a good compromise. Analysis of the timescale dependence of metrics expressed as Laplace transforms leads to an alternative metric that gives closer agreement with FEI at the expense of considering methane over longer time periods. The short-term behaviour, which is important when metrics are used for emissions trading, is illustrated with simple examples for the four metrics.

scholarly journals Genetic variation in phenology and growth among and within Norway spruce populations from two altitudinal transects in Mid-Norway

Silva Fennica ◽  
2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Tore Skrøppa ◽  
Arne Steffenrem
Keyword(s):  
High Altitude ◽  
Norway Spruce ◽  
Genetic Correlations ◽  
Natural Populations ◽  
Height Growth ◽  
Population Variation ◽  
Clinal Variation ◽  
Short Term ◽  
Narrow Sense Heritability

Progenies from open pollinated cones collected in natural populations of Norway spruce ( (L. Karst.)) distributed along two altitudinal transects in Mid-Norway were tested in the nursery, in short term tests and in long-term field trials. The populations showed clinal variation related to the mean annual temperatures of the populations, with the earliest bud flush and cessation of shoot elongation and lowest height at age nine years for the high altitude populations. Within population variation was considerable as the narrow sense heritability for these traits was 0.67, 0.31 and 0.09 in one transect and 0.55, 0.18 and 0.14 in the other transect, respectively. Lammas shoots occurred in the short term trials with large variation in frequency between years. There was significant family variation for this trait, but also interactions between populations and year. The variance within populations was considerably larger in the populations from low altitude compared to the high-altitude populations. Significant genetic correlations between height and phenology traits and damage scores indicate that families flushing early and ceasing growth late were taller. Taller families also had higher frequencies of damages. Selection of the top 20% families for height growth in short term tests at age nine years gave a simulated gain of 11% increased height growth at age 18 years in long term trials at altitudes similar to those of origin of the populations. The gain was negative when high altitude populations were selected based on testing in the lowland.Picea abies

scholarly journals Impacts of Climate Change: Can Fisheries and Aquaculture Sectors Survive the Wave?

2020 ◽  
Vol 4 (1) ◽  
pp. 78
Author(s):  
Talent Ndlovu ◽  
Sylvain Charlebois
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Food Security ◽  
Food Insecurity ◽  
Holistic Approach ◽  
Short Term ◽  
Ocean Ecosystem ◽  
The Impact ◽  
Impacts Of Climate Change

Studies have shown the impact of climate change on the ocean ecosystem and the fishing and aquaculture sectors. As global warming intensifies, this will impact communities and communities as the populations of some fish species decline or increase. Research on the impacts of climate change to fisheries will facilitate the development of policies, helping communities to adapt while ensuring resilience and sustainability of the sector(s). This paper assesses the short term and long-term impacts of climate change to the ocean ecosystem, the consequences to economies and communities that rely on fishing for food security. It begins with a review of peer reviewed literature, followed by an analysis of the current policies and ends with some recommendations for governments in the sustainability and management of the ecosystem in the future. Important to note is the impact of human generated hazards and how a more holistic approach to minimizing risks to the ocean ecosystem could resolve threats of food insecurity in future.

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