scholarly journals Tooth Marker of Ecological Abnormality: the Interpretation of Stress in Extinct Mega Herbivores (Proboscideans) of the Siwaliks of Pakistan

2021 ◽  
Author(s):  
Muhammad Ameen ◽  
Abdul Khan ◽  
Rana Ahmad ◽  
Muhammad Ijaz ◽  
Muhammad Imran
Keyword(s):  
Climate Change ◽  
Late Miocene ◽  
Middle Miocene ◽  
Indian Subcontinent ◽  
Climatic Conditions ◽  
C3 Plants ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Enamel Hypoplasia ◽  
Grassland Ecology

Climate effects habitat and define species physiology. Climatic regimes were different in past and adaptability of different species varied. Climate change causes certain stress on animal, recorded as Enamel Hypoplasia (EH). Proboscideans, the mega herbivores were extensively represented in the Siwaliks of Pakistan between Middle Miocene to Pleistocene (~15.2 – ~1.0Ma). The study is carried out on 15 species from 9 genera and 4 families using 319 teeth from 266 individual quarries. Our results revealed 20.06% (64/319) teeth infected by EH. Family Deinotheriidae faced higher stress during the terminal of middle Miocene (EH 25%). Dental structure indicate that this family preferred soft vegetation like C3 plants and failed to survive in grassland ecology at the onset of Late Miocene (~10-9 Ma). Gomphotheriids (EH 21.05%) and Stegodontids (EH 23.40%) survived through warm and dry climatic conditions of the Late Miocene, but could not survive the cool and dry climate of Plio-Pleistocene where grasslands were abundant with less browsing activity. Family Elephantidae (EH 8.75%) was successful in drier conditions, and utilized the exclusive C4 diet in open grasslands as efficient grazers, indicated by their tooth morphology. Elephantids were dominant of the proboscideans in open grassland and drier climate during Plio-Pleistocene in Indian subcontinent. We assume that change in the Siwalik climate was governed by microclimate as in the present day Siwaliks grasslands are widely distributed at low altitudes with lower mean annual precipitation and forestlands still persist in Myanmar and Nepal which receives more rainfall and have lower mean annual temperature.

scholarly journals Assessment of Climate Change Effects on Water Resources in the Yellow River Basin, China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiyong Wu ◽  
Heng Xiao ◽  
Guihua Lu ◽  
Jinming Chen
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Climate Model ◽  
Yellow River ◽  
Yellow River Basin ◽  
Mean Annual Precipitation ◽  
The Yellow River ◽  
Mean Annual Temperature ◽  
The Yellow River Basin

The water resources in the Yellow River basin (YRB) are vital to social and economic development in North and Northwest China. The basin has a marked continental monsoon climate and its water resources are especially vulnerable to climate change. Projected runoff in the basin for the period from 2001 to 2030 was simulated using the variable infiltration capacity (VIC) macroscale hydrology model. VIC was first calibrated using observations and then was driven by the precipitation and temperature projected by the RegCM3 high-resolution regional climate model under the IPCC scenario A2. Results show that, under the scenario A2, the mean annual temperature of the basin could increase by 1.6°C, while mean annual precipitation could decrease by 2.6%. There could be an 11.6% reduction in annual runoff in the basin according to the VIC projection. However, there are marked regional variations in these climate change impacts. Reductions of 13.6%, 25.7%, and 24.6% could be expected in the regions of Hekouzhen to Longmen, Longmen to Sanmenxia, and Sanmenxia to Huayuankou, respectively. Our study suggests that the condition of water resources in the YRB could become more severe in the period from 2001 to 2030 under the scenario A2.

CROP DIVERSIFICATION AS CLIMATE CHANGE ADAPTATION: HOW DO BANGLADESHI FARMERS PERFORM?

2019 ◽  
Vol 10 (02) ◽  
pp. 1950007
Author(s):  
SHAIKH MONIRUZZAMAN
Keyword(s):  
Climate Change ◽  
Negative Binomial ◽  
Negative Binomial Regression ◽  
Structural Instability ◽  
Climatic Conditions ◽  
Crop Diversity ◽  
Climatic Variables ◽  
Mean Annual Temperature ◽  
Crop Diversification ◽  
Cross Sectional

This research is based on the theoretical framework of risk in rural agricultural economy where farmers consider climate change as idiosyncratic risk of production. Under the inter-temporal household consumption smoothing model, this paper considers crop diversification as an ex ante measure to tackle permanent income shock from climate change. This paper examines empirically whether crop diversity is affected by climate change and how this diversity will respond to different climate scenarios. Negative binomial regression models are estimated from a nationally representative sample of 11,389 farmers across Bangladesh and 30-year average of seasonal climatic variables to find the effects of climatic variables on crop diversity. This paper finds that crop diversity is climate-sensitive and this diversity in different locations varies with climatic conditions. This research unveils structural instability between different single cross-sectional models to simulate the effects of climatic variables on crop diversity. It also finds that increases in mean annual temperature by [Formula: see text]C by 2030 and [Formula: see text]C by 2100 have resulted in 26.40% and 149.83% increases in crop diversity compared to its baseline of 2010, respectively. The effects of rainfall scenarios on crop diversity are much lower compared to the effects of temperature.

Pollen-Derived Rainfall and Temperature Estimates from Lake Tanganyika and Their Implication for Late Pleistocene Water Levels

1993 ◽  
Vol 40 (3) ◽  
pp. 343-350 ◽  
Author(s):  
Annie Vincens ◽  
Françoise Chalié ◽  
Raymonde Bonnefille ◽  
Joel Guiot ◽  
Jean-Jacques Tiercelin
Keyword(s):  
Catchment Area ◽  
Lake Tanganyika ◽  
Climatic Conditions ◽  
Water Levels ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
A Value ◽  
Last Glaciation ◽  
Analogue Method ◽  
The Last Glacial

AbstractPalaeoclimatic estimates of mean annual temperature and rainfall in the southern Tanganyika basin between 25,000 and 9000 yr B.P. have been established from two pollen sequences based on the best-analogue method. The results give evidence of a mean temperature decrease of about 4.2°C during the last glaciation, a value consistent with that previously obtained in the catchment area on the Burundi Highlands. This cooling was synchronous with a decrease of mean annual precipitation of about 180 mm/yr. Postglacial climatic conditions were established by 12,700 yr B.P., with warming and wetness continuing to increase from this date onward. These new palaeoclimatic data will be useful for hydrological reconstructions of Lake Tanganyika, particularly during the last glacial age for which the magnitude of water-level fall has been a controversial issue; our rainfall estimates are more consistent with low values (-250 to -300 m fall) than with high ones (-600 m) previously proposed.

scholarly journals 1206. Effects of Climatic Variability on Lyme Disease Outbreaks in California

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S693-S694
Author(s):  
Raghesh Varot Kangath ◽  
Rajasree Pai Ramachandra ◽  
Buddhika Madurapperuma ◽  
Luke Scaroni
Keyword(s):  
Climate Change ◽  
Lyme Disease ◽  
Temperature Anomaly ◽  
Climatic Factors ◽  
Climatic Variables ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Northern Coast ◽  
Santa Cruz ◽  
Cca Ordination

Abstract Background Climate change has increased the risk of tick borne infections. The life cycle and prevalence of deer ticks are strongly influenced by temperature. Warmer temperatures associated with climate change are projected to increase the range of suitable tick habitats driving the spread of Lyme disease (LD). Short winters could also increase tick activity increasing the risk of exposure. This study examines the relationship between LD incidence and temperature-precipitation and their anomalies in CA counties. Methods Trends and relationships of Lyme Disease (LD) cases and climatic factors were analyzed among the California counties from 2000 to 2019. Lyme disease tabulate data and climatic data were obtained from Centers for Disease Control, and NOAA, and Climate Data Guide respectively. Canonical correspondence analysis (CCA) was performed using variables: (i) LD cases, (ii) precipitation & anomaly, and temperature & anomaly. The CCA ordination explained the variability between LD cases and climatic variables. Biplots were used to visualize the associations between LD cases and climatic anomalies. Results We compared the countywide LD cases in relation to climatic factors in California from 2000 to 2019. A total of 96 cases in 2000, 117 cases in 2009, and 144 cases in 2019 were reported in the 55 counties of California. Santa Clara reported the highest LD cases in 2003 (23 cases; 16%), followed by Los Angeles in 2013 (20 cases; 18%) and Santa Cruz in 2017 (19 cases; 13%). CCA ordination showed distinguishable clustering patterns between southern California counties (Santa Clara, Santa Cruz, Alameda, and San Diego) and northern coast and Klamath mountains range (Humboldt, Trinity, Shasta, and Siskiyou) regions (Fig. 1). Moderate mean annual temperature (56.5 °F - 62.5 °F) and temperature anomaly (3.8 °F - 5.5 °F) were the most important variable predictor for high LD outbreak. The CCA ordination shows the relationships between Lyme Disease and climatic variables for the 55 Counties of California. The bottom right circle represents Lyme cases positively correlated with temperature anomaly (3.8 °F - 5.5 °F) and moderate annual mean temperature (56.5 °F - 62.5 °F). The upper left circle represents Lyme cases negatively correlated with mean annual precipitation. Conclusion Moderate temperature with low moist spell anomalies in the south neighboring CA counties showed a positive influence on LD outbreak. The climatic conditions in those areas suitable for Oak trees and masting acorn resulting in the establishment of tick and host (deer) populations. We recommend robust surveillance and lab testing for patients with a history of tick bites in these regions. Disclosures All Authors: No reported disclosures

scholarly journals The Miocene Red Lake macroflora of the Deadman River Formation (Chilcotin Group), Interior Plateau, British Columbia, Canada

2020 ◽  
pp. 213-250
Author(s):  
David R. Greenwood ◽  
Christopher K. West ◽  
James F. Basinger
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Middle Miocene ◽  
Growing Season ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Preliminary Assessment ◽  
Red Lake ◽  
Sampling Effectiveness ◽  
The U.S

Despite early interest in Neogene floras, primarily Miocene sites associated with Mio–Pliocene volcanic deposits of the Interior Plateau of British Columbia, few systematic accounts of the Miocene macrofloras of British Columbia – or elsewhere in non-Arctic Canada – have been published since the pioneering studies of J.W. Dawson and his contemporaries in the late 19th century. In this report, the Red Lake macroflora from sediments of the middle Miocene Deadman River Formation exposed in the Red Lake diatomite mine north of Kamloops, British Columbia, is illustrated, and a preliminary assessment presented, along with a brief review of Miocene floras from British Columbia and the U.S. Pacific Northwest. The Red Lake macroflora contains rare Ginkgo leaves, shoots of Cupressaceae (Cupressinocladus, Metasequoia, Taxodium) and shoots and seeds of Pinaceae (Pseudotsuga, Tsuga), maple (Acer) seeds and leaves, Liquidambar (fruit), Trochodendraceae (Zizyphoides auriculata leaves, Nordenskioeldia interglacialis fruits), leaves of 4 species of red and white oaks (Quercus columbiana, Q. prelobata, Q. pseudolyrata, Quercus sp.), leaves of an alder (Alnus harneyana) and birch (Betula thor), chestnut (Castanea spokanensis), beech (Fagus pacifica), sycamore (Platanus dissecta), elm (Ulmus speciosa), leaves of unidentified taxa, fruits of Tilia pedunculata (Malvaceae) and fruits and inflorescences of other unidentified taxa, and leaves of a reed or rush (indet. monocot). The Red Lake middle Miocene climate reconstructed from leaf physiognomy was temperate and mesic, with mean annual temperature ~11–13°C, mild winters (coldest month mean temperature ~3°C), mean annual precipitation 170 −51/+73 cm/yr, and growing season precipitation ~92 cm, with moderate seasonality of precipitation (three wettest months ~51 cm vs. three driest months ~25 cm). The Red Lake flora shows similarities to middle to late Miocene floras from the U.S. Pacific Northwest (i.e., richness in oaks) but is of much lower diversity and lacks key elements common to many of the contemporaneous U.S. Miocene floras (e.g., foliage of Pinaceae esp. Pinus), and is missing taxa detected in the microflora, a pattern likely due to sampling effectiveness at the Red Lake Mine and sampling of different lithofacies for macro- and microfloras.

scholarly journals Inferencias paleoclimáticas para el Mioceno tardío en la cuenca de Angastaco basadas en el análisis fisionómico foliar: Formación Palo Pintado, Salta, Argentina

2020 ◽  
Vol 47 (2) ◽  
pp. 418
Author(s):  
Juan M. Robledo ◽  
Maricel Y. Horn ◽  
Claudia I. Galli ◽  
Luisa M. Anzótegui
Keyword(s):  
Late Miocene ◽  
Environmental Conditions ◽  
Sedimentary Rocks ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Humid Environment ◽  
The Mean ◽  
La Rioja ◽  
Basin Region

The continental sedimentary rocks that constitute the Palo Pintado Formation of the late Miocene from Salta province, presents a great paleoclimatic interest due to the environmental conditions prevailing during this geochronologic interval. The geological and paleobotanical data suggest that during the sedimentary rocks accumulation of the Palo Pintado Formation (Angastaco Basin), wetter conditions would have existed comparing with other nearby and contemporary Formations, for example the Playa del Zorro Aloformation (late Miocene of Catamarca) and the Chiquimil (late Miocene of Tucumán), Salicas and the Toro Negro Formations (both from the late Miocene of La Rioja). In this study, the margin and the foliar area of the leaves contained on rocks from the Palo Pintado Formation are analyzed, in order to obtain the mean annual temperature (MAT) and the mean annual precipitation (MAP). The resulting values were: 23.98 °C and 330.8 mm. These results are coincident by the interpretation of different authors, who consider that the Palo Pintado Formation would have been deposited under a relatively humid environment, possibly as a consequence of the rains that affected locally the Angastaco basin región.

Depositional setting, fossil flora, and paleoenvironment of the Early Eocene Falkland site, Okanagan Highlands, British Columbia

2009 ◽  
Vol 46 (11) ◽  
pp. 811-822 ◽  
Author(s):  
Robin Y. Smith ◽  
James F. Basinger ◽  
David R. Greenwood
Keyword(s):  
British Columbia ◽  
Climatic Conditions ◽  
Mean Annual Precipitation ◽  
Fossil Flora ◽  
Mean Annual Temperature ◽  
Leaf Margin ◽  
Early Eocene ◽  
Similarity Coefficients ◽  
Okanagan Highlands ◽  
Depositional Setting

The fossil flora and depositional setting of the Early Eocene Falkland site in the southern interior of British Columbia, Canada, is reported in detail for the first time, using a census sampling approach. The Falkland site is part of the series of Okanagan Highlands fossil localities in British Columbia and Washington State that represent relatively cool upland environments within the context of the greenhouse world of the Early Eocene, providing microthermal (mean annual temperature (MAT) < 13 °C) climatic conditions for the establishment of cool-adapted plants geographically adjacent to subtropical elements from lowland floras. Plant community composition of the Falkland flora is most similar to the Republic (Washington) and McAbee (British Columbia) floras based on high Sørenson similarity coefficients, together forming a southern cluster of Okanagan Highlands sites. The site is a lacustrine deposit that formed in a volcanically active landscape. Paleoclimate reconstructions based on leaf physiognomy characterize the site as microthermal (MAT 8.9 ± 2.0 °C by leaf margin analysis or 11.9 ± 2.0 °C by climate leaf analysis multivariate program (CLAMP)), mesic (mean annual precipitation (MAP) 114 [Formula: see text]cm/year), and equable (cold month mean temperature (CMMT) 3.0 ± 2.0 °C). Paleoelevation of the site is estimated to be similar to or slightly higher than modern levels (>1.3 km) during the Early Eocene. The Falkland locality adds new data to the temporal, latitudinal, and altitudinal gradients of the Okanagan Highlands series, reflecting the regional landscape of northwestern North America during the warmest period of the Cenozoic.

scholarly journals Paleoenvironment of the Quilchena flora, British Columbia, during the Early Eocene Climatic Optimum

2016 ◽  
Vol 53 (6) ◽  
pp. 574-590 ◽  
Author(s):  
Rolf W. Mathewes ◽  
David R. Greenwood ◽  
S. Bruce Archibald
Keyword(s):  
British Columbia ◽  
Leaf Size ◽  
Climatic Conditions ◽  
Mean Annual Precipitation ◽  
Size Analysis ◽  
Mean Annual Temperature ◽  
Leaf Margin ◽  
Early Eocene ◽  
Early Eocene Climatic Optimum ◽  
Climatic Optimum

The Quilchena fossil locality is dated (51.5 ± 0.4 Ma) to the Early Eocene Climatic Optimum, and this locality is reconstructed as the warmest and wettest of the Early Eocene upland sites from the Okanagan Highlands of British Columbia and northern Washington State. Mean annual temperature (MAT) is estimated from leaf margin analysis, using 55 dicot morphotypes, as 16.2 ± 2.1 °C/14.6 ± 4.8 °C. Using bioclimatic analysis of 45 nearest living relatives, a moist mesothermal climate is indicated (MAT 12.7–16.6 °C; cold month mean temperature (CMMT) 3.5–7.9 °C; mean annual precipitation (MAP) 103–157 cm/year. Leaf size analysis estimates MAP at 121 ± 39 cm/year. Estimates from the climate leaf analysis multivariate program corroborate these results, although with a slightly cooler MAT (13.3 ± 2.1 °C). Plants that support an interpretation of warm winters with minimal or no frost include Azolla, Glyptostrobus, Taxodium, Keteleeria, Pseudolarix, Eucommia, Dipteronia, Hovenia, Ternstroemia, and others. These thermophilous elements occur together with temperate genera such as Alnus, Betula, Ulmus, Calocedrus, and Fraxinus. Palynological assemblages at Quilchena are dominated by bisaccate conifers and Cupressaceae. Common angiosperms include Ulmus type, triporates, Pterocarya, and Alnus. Insect fossils at Quilchena that today inhabit tropical and subtropical regions also support warm and equable climate without significant frost, and include obligate palm-feeding beetles (Pachymerina), which indicate CMMT perhaps as high as 8 °C. These are found together with temperate aphids, wasps, giant lacewings, brown lacewings, and a panorpoid scorpionfly, supporting an interpretation of equable climatic conditions during the Early Eocene Climatic Optimum.

scholarly journals Evaluation of New CORDEX Simulations Using an Updated Köppen–Trewartha Climate Classification

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 726 ◽  
Author(s):  
Armelle Reca Remedio ◽  
Claas Teichmann ◽  
Lars Buntemeyer ◽  
Kevin Sieck ◽  
Torsten Weber ◽  
...  
Keyword(s):  
Climate Change ◽  
Standard Deviation ◽  
Climatic Research Unit ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Climate Classification ◽  
Climate Services ◽  
Skill Scores ◽  
Observational Uncertainty ◽  
Core Framework

A new ensemble of climate and climate change simulations covering all major inhabited regions with a spatial resolution of about 25 km, from the WCRP CORDEX COmmon Regional Experiment (CORE) Framework, has been established in support of the growing demands for climate services. The main objective of this study is to assess the quality of the simulated climate and its fitness for climate change projections by REMO (REMO2015), a regional climate model of Climate Service Center Germany (GERICS) and one of the RCMs used in the CORDEX-CORE Framework. The CORDEX-CORE REMO2015 simulations were driven by the ECMWF ERA-Interim reanalysis and the simulations were evaluated in terms of biases and skill scores over ten CORDEX Domains against the Climatic Research Unit (CRU) TS version 4.02, from 1981 to 2010, according to the regions defined by the Köppen–Trewartha (K–T) Climate Classification types. The REMO simulations have a relatively low mean annual temperature bias (about ± 0.5 K) with low spatial standard deviation (about ± 1.5 K) in the European, African, North and Central American, and Southeast Asian domains. The relative mean annual precipitation biases of REMO are below ± 50 % in most domains; however, spatial standard deviation varies from ± 30 % to ± 200 %. The REMO results simulated most climate types relatively well with lowest biases and highest skill score found in the boreal, temperate, and subtropical regions. In dry and polar regions, the REMO results simulated a relatively high annual biases of precipitation and temperature and low skill. Biases were traced to: missing or misrepresented processes, observational uncertainty, and uncertainties due to input boundary forcing.

scholarly journals Leaf wax <i>n</i>-alkane pattern and compound-specific δ<sup>13</sup>C of plants and topsoils from semi-arid Mongolia

2019 ◽  
Author(s):  
Julian Struck ◽  
Marcel Bliedtner ◽  
Paul Strobel ◽  
Jens Schumacher ◽  
Enkhtuya Bazarradnaa ◽  
...  
Keyword(s):  
Arid Regions ◽  
Climatic Conditions ◽  
Mean Annual Precipitation ◽  
Average Chain Length ◽  
Mean Annual Temperature ◽  
Alkane Degradation ◽  
Leaf Wax ◽  
Significant Enrichment ◽  
Use Efficiency ◽  
Semi Arid

Abstract. n-Alkane pattern and their compound-specific δ13C signatures are valuable proxies for paleoenvironmental reconstructions. So far, their potential has not been investigated in semi-arid to arid regions. We have therefore analysed the leaf wax n-alkanes and their compound-specific δ13C of five plant species (Poaceae, Cyperaceae, Artemisia spp., Caragana spp. and Larix sp.), and topsoils (0–5 cm) along two transects in central and southern Mongolia. Grasses depict a distinct dominance of the n-C31 homologue, whereas Caragana spp. and Artemisia spp. are dominated by n-C29. Larix sp. is characterized by the mid-chain n-alkanes n-C23 and n-C25. From plant to soil, n-alkane homologue pattern show the potential to differentiate between grass covered sites from those covered by Caragana spp. n-Alkane concentrations and OEP values of the topsoils are distinctly influenced by mean annual temperature, mean annual precipitation and aridity, likely reflecting the degree of n-alkane degradation and biomass production. In contrast, the n-alkane average chain-length and the n-alkane ratio (n-C31 / n-C29 + n-C31) are not affected by climatic parameters. The compound-specific δ13C signatures are strongly corelated to climate, showing a significant enrichment with increasing aridity, indicating the effect of water use efficiency. Our calibration results suggest that long-chain n-alkanes and their compound-specific δ13C signatures have great potential to reconstruct paleoenvironmental and -climatic conditions when used in sediment archives from Mongolia.

Sign in / Sign up

Export Citation Format

Share Document