Influence of climate change on the predicted distributions of the genus Tympanoctomys (Rodentia, Hystricomorpha, Octodontidae), and their conservation implications

2020 ◽  
Vol 101 (5) ◽  
pp. 1364-1379 ◽  
Author(s):  
A P Tarquino-Carbonell ◽  
Ricardo A Ojeda ◽  
Agustina A Ojeda
Keyword(s):  
Environmental Niche ◽  
Climate Data ◽  
Ecological Niche Models ◽  
Geographic Ranges ◽  
Climate Fluctuations ◽  
Modern Times ◽  
Conservation Implications ◽  
General Terms ◽  
Historical Distribution ◽  
Present Distribution

Abstract Viscacha rats (genus Tympanoctomys Yepes, 1942) are ecologically, physiologically, and behaviorally unusual octodontid rodents endemic to the Monte and Patagonian desert biomes of Argentina. The geographic ranges of the different species of Tympanoctomys have been described in general terms but have not been associated with spatial and climate data. Within species, populations are patchily distributed and genetically distinct. We investigated the predicted distribution of Tympanoctomys and the influence of climate fluctuations on their geographic range in historical, current, and future, scenarios. Our objectives were to characterize the environmental niche of the genus, propose a paleoclimatic context for the oldest fossils, characterize the environmental niches for T. barrerae and T. kirchnerorum, and forecast potential future distributions for these taxa. Ecological niche models were constructed using occurrence records from 1941 to the present wherein we identified several precipitation and temperature variables as important predictors of the geographic distributions of the genus, and the species T. barrerae and T. kirchnerorum. Based on our models’ results, we hypothesize that the distribution of Tympanoctomys has contracted from historical to modern times. At the species level, T. kirchnerorum likely experienced the most dramatic change, suffering a large contraction of its historical distribution resulting in its limited present distribution. Given these findings, projected future climate fluctuations and global warming are expected to affect the distributions and persistence of these species.

Updated habitat suitability estimates and conservation implications for the short-tailed chinchilla Chinchilla chinchilla (Lichtenstein, 1830) (Rodentia: Chinchillidae)

2020 ◽  
Vol 15 (3) ◽  
pp. 557-572
Author(s):  
John Stuhler ◽  
Daniela Arenas-Viveros ◽  
Jorge Salazar-Bravo
Keyword(s):  
New Records ◽  
Management Plan ◽  
Suitable Habitat ◽  
Wild Populations ◽  
Ecological Niche Models ◽  
Conservation Implications ◽  
Historical Distribution ◽  
Omission Rate ◽  
Insight Into ◽  
Historical Range

The short-tailed chinchilla (Chinchilla chinchilla) is a species classified as endangered throughout its distribution and for which neither a conservation nor management plan exists. Ecological niche models (ENMs) allow detection of potential areas of occurrence for species that are rare and/or of conservation interest. Here, we built and evaluated a suite of ENMs that incorporated new records for the species in Bolivia and removed those whose veracity could not be confirmed to provide an updated estimate of the extent of suitable habitat for C. chinchilla. Following model selection based on partial ROC, omission rate, and AICc, we then projected our top models across the historical distribution of C. chinchilla to identify locations of potentially suitable habitat. An ensemble of top models highlighted suitable habitat in Argentina, Bolivia, Chile, and Peru, with values of probability of suitable habitat up to 0.72. Together, these results demonstrate that suitable habitat still exists across the historical range of this species, provide insight into the climatic niche of this species, and highlight areas across the four countries for which future surveys of wild populations may be worthwhile.

scholarly journals Climate variability impacts on diversification processes in a biodiversity hotspot: a phylogeography of ancient pseudoscorpions in south-western Australia

2019 ◽  
Vol 186 (4) ◽  
pp. 934-949 ◽  
Author(s):  
Danilo Harms ◽  
J Dale Roberts ◽  
Mark S Harvey
Keyword(s):  
Phylogenetic Analyses ◽  
Distribution Patterns ◽  
Biodiversity Hotspot ◽  
Molecular Dating ◽  
Environmental Niche ◽  
Ecological Niche Models ◽  
The South ◽  
Niche Modelling ◽  
South West ◽  
Western Division

Abstract The south-western division of Australia is the only biodiversity hotspot in Australia and is well-known for extreme levels of local endemism. Climate change has been identified as a key threat for flora and fauna, but very few data are presently available to evaluate its impact on invertebrate fauna. Here, we derive a molecular phylogeography for pseudoscorpions of the genus Pseudotyrannochthonius that in the south-west are restricted to regions with the highest rainfall. A dated molecular phylogeny derived from six gene fragments is used for biogeographic reconstruction analyses, spatial mapping, environmental niche-modelling, and to infer putative species. Phylogenetic analyses uncover nine clades with mostly allopatric distributions and often small linear ranges between 0.5 and 130 km. Molecular dating suggests that the origins of contemporary diversity fall into a period of warm/humid Palaeogene climates, but splits in the phylogeny coincide with major environmental shifts, such as significant global cooling during the Middle Miocene. By testing several models of historical biogeography available for the south-west, we determine that Pseudotyrannochthonius is an ancient relict lineage that principally follows a model of allopatric speciation in mesic zone refugia, although there are derivations from this model in that some species are older and distribution patterns more complex than expected. Ecological niche models indicate that drier and warmer future climates will lead to range contraction towards refugia of highest rainfall, probably mimicking past variations that have generated high diversity in these areas. Their conservation management will be crucial for preserving the unique biodiversity heritage of the south-west.

On the Kinematics of the Closed Epicyclic Differential Gears

1982 ◽  
Vol 104 (4) ◽  
pp. 712-719 ◽  
Author(s):  
R. J. Willis
Keyword(s):  
Kinematic Analysis ◽  
Tangential Velocity ◽  
Planetary Gear ◽  
Modern Times ◽  
General Terms ◽  
Epicyclic Gear ◽  
Differential Gear ◽  
Velocity Triangle ◽  
Overall Ratio ◽  
Mathematical Relationships

The epicyclic differential gear has been known in modern times since 1575 when it appeared as a mechanism in a clock. Artifacts from an ancient shipwreck prove that it was known to the ancient Greeks at least 100 hundred years before Christ. The methods of kinematic analysis by either the relative angular velocity method or the instant center and linear velocity method, as given in the literature, are oriented toward specific solutions rather than general ones; they do not readily allow for parametric trend studies and they require a degree of imagination and intuition which may well be beyond the capabilities of those who are not practitioners of the art. The discussed methodology defines simple and compound epicyclic gears in terms of the overall ratio of a geometrically similar planetary gear. The kinematic analysis is derived in general terms for both the simple and compound epicyclic gear. It is shown that location of the point of zero tangential velocity of the velocity triangle relative to the system datum governs the characteristics of the gearset and whether it will perform as a differential gearset, or as a solar, star, or planetary gear. Simple mathematical relationships are given which define the proportions of the component gears, their speeds (rpm) and directions of rotations, and the resulting power splits. The formulas may be incorporated into simple computer programs oriented toward specific design requirements.

scholarly journals Modelling the potential ecological niche of domesticated buckwheat in China: archaeological evidence, environmental constraints and climate change

2021 ◽  
Author(s):  
Marta Krzyzanska ◽  
Harriet V. Hunt ◽  
Enrico R. Crema ◽  
Martin K. Jones
Keyword(s):  
Ecological Niche ◽  
Species Distribution Model ◽  
Modern China ◽  
Distribution Model ◽  
Distribution Data ◽  
Environmental Niche ◽  
Dispersal Pattern ◽  
Present Distribution ◽  
Potential Area ◽  
Over Time

AbstractWe present a species distribution model (SDM) of Fagopyrum esculentum (buckwheat) in China using present distribution data and estimates for the past based on palaeoclimatic reconstructions. Our model estimates the potential area suitable for buckwheat cultivation over the last 8,000 years, with northeast China consistently showing the highest suitability, providing insights on the discrepancy between the location of the earliest archaeobotanical records in the area and its origins in southwest China based on biogeographic and genetic data. The model suggests little to no variation over time in the spatial extent of the potential area suitable for buckwheat cultivation. In the northern parts of China, the limits of the ecological niche largely fall within the borders of the study area, while to the west it never extends into the main Tibetan plateau, explaining the lack of fossil evidence from Central Asia. In the southwest, the niche overlaps with the borders of modern China, which supports this direction as a viable route of westward dispersal. The comparison between the prediction from the model and sites with archaeobotanical evidence for Fagopyrum indicates that the environmental niche it occupied remained stable over time. This may contrast with a dispersal pattern characterised by continuous adaptations to new environments facilitated by human activity, which may be suggested for other major and minor crops.

scholarly journals Zoning of the republic of Kazakhstan as to the risk of natural focal diseases in animals: the case of rabies and anthrax

2020 ◽  
Vol 13 (1) ◽  
pp. 134-144 ◽  
Author(s):  
Sarsenbay K. Abdrakhmanov ◽  
Yersyn Y. Mukhanbetkaliyev ◽  
Fedor I. Korennoy ◽  
Kanatzhan K. Beisembayev ◽  
Ablaikhan S. Kadyrov ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Environmental Niche ◽  
Climate Data ◽  
Niche Modelling ◽  
Veterinary Service ◽  
Explanatory Variables ◽  
Vegetation Fraction ◽  
Domestic Livestock ◽  
The Republic ◽  
Categorical Maps

Rabies and anthrax, being natural focal diseases, are characterized by the ability to persist in areas with a certain combination of environmental factors without human intervention. These infections annually cause sporadic outbreaks in domestic, livestock and wild animals in the Republic of Kazakhstan (RK) receiving close attention of the veterinary service. In particular, targeted mass vaccination and surveillance are conducted, which requires zoning of the country according to the exposure to the diseases.This paper presents a zoning approach based on the estimation of suitability to the study diseases using the Environmental Niche Modelling method. Retrospective data on animal rabies outbreaks in the RK for 2003-2014, as well as data on anthrax burial sites for 1933-2014 were used. The following environmental factors were treated as potential explanatory variables: 1) a set of climate data derived variables BIOCLIM; 2) altitude above the sea level; 3) land cover type; 4) the maximum green vegetation fraction and 5) soil type.The modelling outcomes for both diseases indicate elevated risks along the northern and southeastern borders of the RK that not only follows the distribution of historic disease cases, but also accounts for potentially suitable environmental conditions. To comply with the requirements of the veterinary service, gridded risk maps were converted into categorical maps by averaging risk values within municipal districts and ranking according to four categories: low, medium, high, and very high.The maps obtained may be used as recommendations to the veterinary service as a basis for developing regionspecific anti-epizootic measures. 

scholarly journals Snow and weather climatic control on snow avalanche occurrence fluctuations over 50 yr in the French Alps

2011 ◽  
Vol 7 (6) ◽  
pp. 4173-4221
Author(s):  
H. Castebrunet ◽  
N. Eckert ◽  
G. Giraud
Keyword(s):  
Regression Models ◽  
Snow Avalanche ◽  
Weather Data ◽  
Climate Data ◽  
Winter Climate ◽  
Continuous Increase ◽  
Climate Fluctuations ◽  
French Alps ◽  
Weather Patterns ◽  
Short Period

Abstract. Snow avalanche activity is controlled to a large extent by snow and weather patterns. However, its response to climate fluctuations remains poorly documented. Previous studies have focused on direct extraction of trends in avalanche and winter climate data, and this study employs a time-implicit method to model annual avalanche activity in the French Alps during the 1958–2009 period from its most representative climatic drivers. Modeled snow and weather data for different elevations and aspects are considered as covariates that explain actual observed avalanche counts, modeled instability indexes, and a combination of both avalanche activity indicators. These three series present relatively similar fluctuations over the period and good consistency with historically harsh winters. A stepwise procedure is used to obtain regression models that accurately represent trends as well as high and low peaks with a small number of physically meaningful covariates, showing their climatic relevance. The activity indicators and their regression models seen as time series show, within a high interannual variability, a predominant bell-shaped pattern presumably related to a short period of colder and snowier winters around 1980, as well as a very slight but continuous increase between 1975 and 2000 concomitant with warming. Furthermore, the regression models quantify the respective weight of the different covariates, mostly temperature anomalies and south-facing snowpack characteristics to explain the trends and most of the exceptional winters. Regional differences are discussed as well as seasonal variations between winter and spring activity and confirm rather different snow and weather regimes influencing avalanche activity over the Northern and Southern Alps, depending on the season.

Climate, History, and Social Change in Sweden and the Baltic Sea Area From About 1700

2017 ◽  
Author(s):  
Sven Lilja
Keyword(s):  
Social Change ◽  
Large Scale ◽  
Agricultural Sector ◽  
Industrial Society ◽  
Political Agenda ◽  
Environmental Discourse ◽  
Climate Data ◽  
Climate History ◽  
Climate Fluctuations ◽  
Climate Research

The growing concern about global warming has turned focus in Sweden and other Baltic countries toward the connection between history and climate. Important steps have been taken in the scientific reconstruction of climatic parables. Historic climate data have been published and analyzed, and various proxy data have been used to reconstruct historic climate curves. The results have revealed an ongoing regional warming from the late 17th to the early 21st century. The development was not continuous, however, but went on in a sequence of warmer and colder phases.Within the fields of history and socially oriented climate research, the industrial revolution has often been seen as a watershed between an older and a younger climate regime. The breakthrough of the industrial society was a major social change with the power to influence climate. Before this turning point, man and society were climate dependent. Weather and short-term climate fluctuations had major impacts on agrarian culture. When the crops failed several years in sequence, starvation and excess mortality followed. As late as 1867–1869, northern Sweden and Finland were struck by starvation due to massive crop failures.Although economic activities in the agricultural sector had climatic effects before the industrial society, when industrialization took off in Sweden in the 1880s it brought an end to the large-scale starvations, but also the start of an economic development that began to affect the atmosphere in a new and broader way. The industrial society, with its population growth and urbanization, created climate effects. Originally, however, the industrial outlets were not seen as problems. In the 18th century, it was thought that agricultural cultivation could improve the climate, and several decades after the industrial take-off there still was no environmental discourse in the Swedish debate. On the contrary, many leading debaters and politicians saw the tall chimneys, cars, and airplanes as hopeful signs in the sky. It was not until the late 1960s that the international environmental discourse reached Sweden. The modern climate debate started to make its imprints as late as the 1990s.During the last two decades, the Swedish temperature curve has unambiguously turned upwards. Thus, parallel to the international debate, the climate issue has entered the political agenda in Sweden and the other Nordic countries. The latest development has created a broad political consensus in favor of ambitious climate goals, and the people have gradually started to adapt their consumption and lifestyles to the new prerequisites.Although historic climate research in Sweden has had a remarkable expansion in the last decades, it still leans too much on its climate change leg. The clear connection between the climate fluctuations during the last 300 years and the major social changes that took place in these centuries needs to be further studied.

scholarly journals Different diversification histories in tropical and temperate lineages in the ascomycete subfamily Protoparmelioideae (Parmeliaceae)

MycoKeys ◽  
2018 ◽  
Vol 36 ◽  
pp. 1-19 ◽  
Author(s):  
Garima Singh ◽  
Francesco Dal Grande ◽  
Jan Schnitzler ◽  
Markus Pfenninger ◽  
Imke Schmitt
Keyword(s):  
Species Distributions ◽  
Divergence Times ◽  
Temporal Context ◽  
Evolutionary Processes ◽  
Climate Fluctuations ◽  
The Past ◽  
Divergence Dating ◽  
Present Distribution ◽  
Time Of Origin ◽  
Key Innovations

Background: Environment and geographic processes affect species’ distributions as well as evolutionary processes, such as clade diversification. Estimating the time of origin and diversification of organisms helps us understand how climate fluctuations in the past might have influenced the diversification and present distribution of species. Complementing divergence dating with character evolution could indicate how key innovations have facilitated the diversification of species.Methods: We estimated the divergence times within the newly recognised subfamily Protoparmelioideae (Ascomycota) using a multilocus dataset to assess the temporal context of diversification events. We reconstructed ancestral habitats and substrate using a species tree generated in *Beast.Results: We found that the diversification in Protoparmelioideae occurred during the Miocene and that the diversification events in the tropical cladeMaroninapredate those of the extratropicalProtoparmelia. Character reconstructions suggest that the ancestor of Protoparmelioideae was most probably a rock-dwelling lichen inhabiting temperate environments.Conclusions: Major diversification within the subtropical/tropical genusMaroninaoccurred between the Paleocene and Miocene whereas the diversifications within the montane, arctic/temperate genusProtoparmeliaoccurred much more recently, i.e. in the Miocene.

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