Elevated CO 2 ameliorates birch response to high temperature and frost stress: implications for modeling climate-induced geographic range shifts

Oecologia ◽  
1998 ◽  
Vol 114 (3) ◽  
pp. 335-342 ◽  
Author(s):  
P. M. Wayne ◽  
E. G. Reekie ◽  
F. A. Bazzaz
2015 ◽  
Vol 18 (9) ◽  
pp. 944-953 ◽  
Author(s):  
Jennifer M. Sunday ◽  
Gretta T. Pecl ◽  
Stewart Frusher ◽  
Alistair J. Hobday ◽  
Nicole Hill ◽  
...  

Author(s):  
Colin J. Carlson ◽  
Gregory F. Albery ◽  
Cory Merow ◽  
Christopher H. Trisos ◽  
Casey M. Zipfel ◽  
...  

AbstractAt least 10,000 species of mammal virus are estimated to have the potential to spread in human populations, but the vast majority are currently circulating in wildlife, largely undescribed and undetected by disease outbreak surveillance1,2,3. In addition, changing climate and land use are already driving geographic range shifts in wildlife, producing novel species assemblages and opportunities for viral sharing between previously isolated species4,5. In some cases, this will inevitably facilitate spillover into humans6,7—a possible mechanistic link between global environmental change and emerging zoonotic disease8. Here, we map potential hotspots of viral sharing, using a phylogeographic model of the mammal-virus network, and projections of geographic range shifts for 3,870 mammal species under climate change and land use scenarios for the year 2070. Range-shifting mammal species are predicted to aggregate at high elevations, in biodiversity hotspots, and in areas of high human population density in Asia and Africa, driving the cross-species transmission of novel viruses at least 4,000 times. Counter to expectations, holding warming under 2°C within the century does not reduce new viral sharing, due to greater range expansions—highlighting the need to invest in surveillance even in a low-warming future. Most projected viral sharing is driven by diverse hyperreservoirs (rodents and bats) and large-bodied predators (carnivores). Because of their unique dispersal capacity, bats account for the majority of novel viral sharing, and are likely to share viruses along evolutionary pathways that could facilitate future emergence in humans. Our findings highlight the urgent need to pair viral surveillance and discovery efforts with biodiversity surveys tracking range shifts, especially in tropical countries that harbor the most emerging zoonoses.


2021 ◽  
Vol 9 ◽  
Author(s):  
Victoria Culshaw ◽  
Mario Mairal ◽  
Isabel Sanmartín

Geographic range shifts are one major organism response to climate change, especially if the rate of climate change is higher than that of species adaptation. Ecological niche models (ENM) and biogeographic inferences are often used in estimating the effects of climatic oscillations on species range dynamics. ENMs can be used to track climatic suitable areas over time, but have often been limited to shallow timescales; biogeographic inference can reach greater evolutionary depth, but often lacks spatial resolution. Here, we present a simple approach that treats them as independent and complementary sources of evidence, which, when used in partnership, can be employed to reconstruct geographic range shifts over deep evolutionary timescales. For testing this, we chose two extreme African disjunctions: Camptoloma (Scrophulariaceae) and Canarina (Campanulaceae), each comprising of three species disjunctly distributed in Macaronesia and eastern/southern Africa. Using inferred ancestral ranges in tandem with preindustrial and paleoclimate ENM hindcastings, we show that the disjunct pattern was the result of fragmentation and extinction events linked to Neogene aridification cycles. Our results highlight the importance of considering temporal resolution when building ENMs for rare endemics with small population sizes and restricted climatic tolerances such as Camptoloma, for which models built on averaged monthly variables were more informative than those based on annual bioclimatic variables. Additionally, we show that biogeographic information can be used as truncation threshold criteria for building ENMs in the distant past. Our approach is suitable when there is sparse sampling on species occurrences and associated patterns of genetic variation, such as in the case of ancient endemics with widely disjunct distributions as a result of climate change.


Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 630 ◽  
Author(s):  
Karina De Oliveira Teixeira ◽  
Thiago Cesar Lima Silveira ◽  
Birgit Harter-Marques

Climate change is suggested to be one of the possible drivers of decline in pollinators. In this paper, we applied an ecological niche model to modeling distributional responses in face of climate changes for the subspecies of Melipona quadrifasciata Lepeletier. This species is divided into two subspecies based on difference in the yellow tergal stripes, which are continuous in M. q. quadrifasciata and interrupted in M. q. anthidioides. The geographic distribution of each subspecies is also distinct. M. q. quadrifasciata is found in colder regions in the Southern states of Brazil, whereas M. q. anthidioides is found in habitats with higher temperatures, suggesting that ecological features, such as adaption to distinct climatic conditions may take place. Thus, the possibility of having diff erent responses in geographic range shifts to future climate scenario would be expected. This study aimed to investigate the eff ects of climate changes on the distribution of the two M. quadrifasciata subspecies in Brazil, using an ecological niche model by the MaxEnt algorithm. Our results indicate that the subspecies showed clear diff erences in geographic shift patterns and increased climate niche overlap in the future scenarios. M. q. anthidioides will have the potential for an increase of suitable climatic conditinos in the Atlantic Forest, and towards the Pampa biome, while M. q. quadrifasciata will suffer a reduction of adequate habitats in almost all of its current geographic distribution. Given the potential adverse eff ects of climate changes for this subspecies, conservation actions are urgently needed to avoid that it goes extinct.


Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.


Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


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