scholarly journals Evaluating the responses of three closely related small mammal lineages to climate change across the Paleocene–Eocene thermal maximum

Paleobiology ◽  
2021 ◽  
pp. 1-23
Author(s):  
Natasha S. Vitek ◽  
Paul E. Morse ◽  
Doug M. Boyer ◽  
Suzanne G. Strait ◽  
Jonathan I. Bloch
Keyword(s):  
Climate Change ◽  
Morphological Change ◽  
Morphological Changes ◽  
Mammalian Species ◽  
Bighorn Basin ◽  
Faunal Assemblages ◽  
Thermal Maximum ◽  
Crown Shape ◽  
Promising Area ◽  
The Impact

Abstract Interpreting the impact of climate change on vertebrates in the fossil record can be complicated by the effects of potential biotic drivers on morphological patterns observed in taxa. One promising area where this impact can be assessed is a high-resolution terrestrial record from the Bighorn Basin, Wyoming, that corresponds to the Paleocene–Eocene thermal maximum (PETM), a geologically rapid (~170 kyr) interval of sustained temperature and aridity shifts about 56 Ma. The PETM has been extensively studied, but different lines of research have not yet been brought together to compare the timing of shifts in abiotic drivers that include temperature and aridity proxies and those of biotic drivers, measured through changes in floral and faunal assemblages, to the timing of morphological change within mammalian species lineages. We used a suite of morphometric tools to document morphological changes in molar crown morphology of three lineages of stem erinaceid eulipotyphlans. We then compared the timing of morphological change to that of both abiotic and other biotic records through the PETM. In all three species lineages, we failed to recover any significant changes in tooth crown shape or size within the PETM. These results contrast with those documented previously for lineages of medium-sized mammals, which show significant dwarfing within the PETM. Our results suggest that biotic drivers such as shifts in community composition may have also played an important role in shaping species-level patterns during this dynamic interval in Earth history.

scholarly journals Mammal faunal response to the Paleogene hyperthermals ETM2 and H2

2015 ◽  
Vol 11 (2) ◽  
pp. 1371-1405
Author(s):  
A. E. Chew
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Bighorn Basin ◽  
Early Eocene ◽  
The South ◽  
Deep Time ◽  
Early Eocene Climatic Optimum ◽  
South Central ◽  
Species Vulnerability ◽  
Thermal Maximum

Abstract. Scientists are increasingly turning to deep-time fossil records to decipher the long-term consequences of climate change in the race to preserve modern biotas from anthropogenically driven global warming. "Hyperthermals" are past intervals of geologically rapid global warming that provide the opportunity to study the effects of climate change on existing faunas over thousands of years. A series hyperthermals is known from the early Eocene (∼56–54 million years ago), including the Paleocene-Eocene Thermal Maximum (PETM) and two subsequent hyperthermals, Eocene Thermal Maximum 2 (ETM2) and H2. The later hyperthermals occurred following the onset of warming at the Early Eocene Climatic Optimum (EECO), the hottest sustained period of the Cenozoic. The PETM has been comprehensively studied in marine and terrestrial settings, but the terrestrial biotic effects of ETM2 and H2 are unknown. Their geochemical signatures have been located in the northern part of the Bighorn Basin, WY, USA, and their levels can be extrapolated to an extraordinarily dense, well-studied terrestrial mammal fossil record in the south-central part of the basin. High-resolution, multi-parameter paleoecological analysis reveals significant peaks in species diversity and turnover and changes in abundance and relative body size at the levels of ETM2 and H2 in the south-central Bighorn Basin record. In contrast with the PETM, faunal change at the later hyperthermals is less extreme, does not include immigration and involves a proliferation of body sizes, although abundance shifts tend to favor smaller congeners. Faunal response at ETM2 and H2 is distinctive in its high proportion of species losses potentially related to heightened species vulnerability in response to the changes already underway at the beginning of the EECO. Faunal response at ETM2 and H2 is also distinctive in high proportions of beta richness, suggestive of increased geographic dispersal related to transient increases in habitat (floral) complexity and/or precipitation or seasonality of precipitation. These results suggest that rapid ecological changes, increased heterogeneity in species incidence, and heightened species vulnerability and loss may be expected across most of North America in the near future in response to anthropogenically-driven climate change.

scholarly journals Synchronizing early Eocene deep-sea and continental records – cyclostratigraphic age models for the Bighorn Basin Coring Project drill cores

2018 ◽  
Vol 14 (3) ◽  
pp. 303-319 ◽  
Author(s):  
Thomas Westerhold ◽  
Ursula Röhl ◽  
Roy H. Wilkens ◽  
Philip D. Gingerich ◽  
William C. Clyde ◽  
...  
Keyword(s):  
Deep Sea ◽  
Large Scale ◽  
Major Change ◽  
Terrestrial Ecosystems ◽  
Geochemical Data ◽  
Bighorn Basin ◽  
Early Eocene ◽  
Thermal Maximum ◽  
The Impact ◽  
Drill Cores

Abstract. A consistent chronostratigraphic framework is required to understand the effect of major paleoclimate perturbations on both marine and terrestrial ecosystems. Transient global warming events in the early Eocene, at 56–54 Ma, show the impact of large-scale carbon input into the ocean–atmosphere system. Here we provide the first timescale synchronization of continental and marine deposits spanning the Paleocene–Eocene Thermal Maximum (PETM) and the interval just prior to the Eocene Thermal Maximum 2 (ETM-2). Cyclic variations in geochemical data come from continental drill cores of the Bighorn Basin Coring Project (BBCP, Wyoming, USA) and from marine deep-sea drilling deposits retrieved by the Ocean Drilling Program (ODP). Both are dominated by eccentricity-modulated precession cycles used to construct a common cyclostratigraphic framework. Integration of age models results in a revised astrochronology for the PETM in deep-sea records that is now generally consistent with independent 3He age models. The duration of the PETM is estimated at ∼ 200 kyr for the carbon isotope excursion and ∼ 120 kyr for the associated pelagic clay layer. A common terrestrial and marine age model shows a concurrent major change in marine and terrestrial biota ∼ 200 kyr before ETM-2. In the Bighorn Basin, the change is referred to as Biohorizon B and represents a period of significant mammalian turnover and immigration, separating the upper Haplomylus–Ectocion Range Zone from the Bunophorus Interval Zone and approximating the Wa-4–Wa-5 land mammal zone boundary. In sediments from ODP Site 1262 (Walvis Ridge), major changes in the biota at this time are documented by the radiation of a “second generation” of apical spine-bearing sphenolith species (e.g., S. radians and S. editus), the emergence of T. orthostylus, and the marked decline of D. multiradiatus.

scholarly journals Synchronizing early Eocene deep-sea and continental records – new cyclostratigraphic age models from the Bighorn Basin Coring Project

2017 ◽  
Author(s):  
Thomas Westerhold ◽  
Ursula Röhl ◽  
Roy Wilkens ◽  
Philip D. Gingerich ◽  
Will Clyde ◽  
...  
Keyword(s):  
Deep Sea ◽  
Large Scale ◽  
Major Change ◽  
Terrestrial Ecosystems ◽  
Geochemical Data ◽  
Bighorn Basin ◽  
Early Eocene ◽  
Ocean Drilling Program ◽  
Thermal Maximum ◽  
The Impact

Abstract. A consistent stratigraphic framework is required to understand the effect of major climate perturbations of the geological past on both marine and terrestrial ecosystems. Transient global warming events in the early Eocene, 56–54 Ma ago, show the impact of large scale input of carbon into the ocean-atmosphere system. Here we provide the first time-scale synchronization of continental and marine deposits spanning the Paleocene-Eocene Thermal Maximum (PETM) and the interval just prior to the Eocene Thermal Maximum 2 (ETM-2). Cyclic variations in geochemical data come from continental drill cores of the Bighorn Basin Drilling Project (BBCP, Wyoming, USA) and from marine deep-sea drilling deposits retrieved by the Ocean Drilling Program (ODP). Both are dominated by eccentricity modulated precession cycles that are used to construct a common cyclostratigraphic framework. Integration of age models results in a revised astrochronology for the PETM in deep-sea records that is now generally consistent with independent 3He age models. The duration of the PETM is estimated at ~ 200 kyr for the CIE and ~ 120 kyr for the pelagic clay layer. A common terrestrial and marine age model shows a concurrent major change in marine and terrestrial biotas ~ 200 kyr before ETM-2. In the Bighorn Basin, the change is referred to as Biohorizon B, and it represents a period of significant mammalian turnover and immigration, separating the upper Haplomylus-Ectocion Range Zone from the Bunophorus Interval Zone and approximating the Wa-4–Wa-5 land mammal zone boundary. In sediments from ODP Site 1262 (Walvis Ridge), major changes in the biota at this time are documented by the radiation of a 2nd generation of apical spine-bearing sphenoliths species (e.g., S. radians and S. editus), the emergence of T. orthostylus, and the marked decline of D. multiradiatus.

Comparative assessment of morphological mechanisms of maintaining structural liver homeostasis in the dynamics of exposure to coal-rock dust and sodium fluoride on the body

2020 ◽  
pp. 189-194
Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova
Keyword(s):  
Sodium Fluoride ◽  
Morphological Changes ◽  
The Body ◽  
System Level ◽  
Production Factor ◽  
Coal Rock ◽  
The Impact ◽  
Structural Homeostasis ◽  
Rock Dust

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.

HOW CLIMATE CHANGE CAN INFLUENCE THE AGRICULTURE IN UKRAINE: A REVIEW

2020 ◽  
Author(s):  
N. Maidanovych ◽  
Keyword(s):  
Climate Change ◽  
Crop Yields ◽  
Soil Surface ◽  
Winter Period ◽  
Negative Consequences ◽  
Resource Saving ◽  
Impact Of Climate Change ◽  
Positive Effects ◽  
Average Annual Temperature ◽  
The Impact

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.

A MODELING SYSTEM FOR CLIMATE CHANGE RISK ASSESSMENT, MANAGEMENT AND HEDGING IN COASTAL AREAS

2017 ◽  
Author(s):  
Sergei Soldatenko ◽  
Sergei Soldatenko ◽  
Genrikh Alekseev ◽  
Genrikh Alekseev ◽  
Alexander Danilov ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Coastal Areas ◽  
Mitigation Strategies ◽  
System Structure ◽  
The Arctic ◽  
Risk Modeling ◽  
Wide Range ◽  
Adverse Weather ◽  
The Impact

Every aspect of human operations faces a wide range of risks, some of which can cause serious consequences. By the start of 21st century, mankind has recognized a new class of risks posed by climate change. It is obvious, that the global climate is changing, and will continue to change, in ways that affect the planning and day to day operations of businesses, government agencies and other organizations and institutions. The manifestations of climate change include but not limited to rising sea levels, increasing temperature, flooding, melting polar sea ice, adverse weather events (e.g. heatwaves, drought, and storms) and a rise in related problems (e.g. health and environmental). Assessing and managing climate risks represent one of the most challenging issues of today and for the future. The purpose of the risk modeling system discussed in this paper is to provide a framework and methodology to quantify risks caused by climate change, to facilitate estimates of the impact of climate change on various spheres of human activities and to compare eventual adaptation and risk mitigation strategies. The system integrates both physical climate system and economic models together with knowledge-based subsystem, which can help support proactive risk management. System structure and its main components are considered. Special attention is paid to climate risk assessment, management and hedging in the Arctic coastal areas.

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