Holocene Climatic Change in the Northern Midwest: Pollen-Derived Estimates

1984 ◽  
Vol 22 (3) ◽  
pp. 361-374 ◽  
Author(s):  
P. J. Bartlein ◽  
T. Webb ◽  
E. Fleri
Keyword(s):  
Maximum Temperature ◽  
Pollen Record ◽  
Regression Equations ◽  
Climate Data ◽  
The South ◽  
The North ◽  
Modern Pollen ◽  
Quantitative Estimates ◽  
Multiple Regression Models ◽  
July Temperature

Mapping of Holocene pollen data in the midwestern United States has revealed several broadscale vegetational changes that can be interpreted in climatic terms. These changes include (1) the early Holocene northward movement of the spruce-dominated forest and its later southward movement after 3000 yr B.P. and (2) the eastward movement of the prairie/forest border into southwestern Wisconsin by 8000 yr B.P. and its subsequent westward retreat after 6000 yr B.P. When certain basic assumptions are met, multiple regression models can be derived from modern pollen and climate data and used to transform the pollen record of these vegetational changes into quantitative estimates of temperature or precipitation. To maximize the reliability of the regression equations, we followed a sequence of procedures that minimize violations of the assumptions that underlie regression analysis. Reconstructions of precipitation during the Holocene indicated that from 9000 to 6000 yr B.P. precipitation decreased by 10 to 25% over much of the Midwest, while mean July temperature increased by 0.5° to 2.0°C. At 6000 yr B.P. precipitation was less than 80% of its modern values over parts of Wisconsin and Minnesota. After 6000 yr B.P. precipitation generally increased, while mean July temperature decreased in the north, and increased in the south. The time of the maximum temperature varies within the Midwest and is earlier in the north and later in the south.

Elevational transects of modern pollen samples: Site-specific temperatures as a tool for palaeoclimate reconstructions in the Alps

The Holocene ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Giulia Furlanetto ◽  
Cesare Ravazzi ◽  
Federica Badino ◽  
Michele Brunetti ◽  
Elena Champvillair ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Weighted Averaging ◽  
Taxonomic Resolution ◽  
Pollen Deposition ◽  
High Mountain ◽  
European Alps ◽  
Climate Data ◽  
Sample Site ◽  
Modern Pollen ◽  
July Temperature

The potential of quantitatively reconstructing climate from modern pollen assemblages from high mountain environments has been widely debated but seldom tested. We analysed the pollen deposition in 53 surface samples (mosses) in relation to July temperature in two elevational transects in the European Alps. Each surface-sample site was assigned climate data derived from the local-scale climate. We compared our results with a larger calibration set extracted from the European Modern Pollen Database (EMPD) and centred on the European Alps. This also was assigned local climate data. The main calibration set (234 pollen samples) had Alnus harmonized at genus level; in contrast, a second set was selected (174) that retained the taxonomic resolution of Alnus viridis, which is one of the main climate indicators in the timberline ecotone. The overall and individual pollen responses to July temperature were inferred by canonical correspondence analysis (CCA), generalized linear regression (eHOF) and weighted averaging (WA). Quantitative climate reconstructions for each sample site of the two elevational transects were obtained using transfer functions, that is, WA and WA partial least squares (WA-PLS) regressions. In each calibration set, around 30% of the pollen taxa show a relationship with July temperature through monotonic or unimodal functions. The best transfer function obtained has a good statistical performance, with a determination coefficient ( r2) of 0.74. We propose new calibration procedures formulated to include the full climate space of the modelled taxa, as well as to account for uphill pollen transport in the high mountains and for human activity.

scholarly journals Determination of ecological conditions and geographical distribution of vegetation in the Goksu basin

2022 ◽  
pp. 51-61
Author(s):  
Fatih Karaosmanoglu
Keyword(s):  
Geographical Distribution ◽  
Plant Species ◽  
Geographical Area ◽  
Climatic Conditions ◽  
Physical Factors ◽  
Climate Data ◽  
The South ◽  
Climate Type ◽  
Ecological Conditions ◽  
The North

On the ecological conditions and distribution of vegetation in any geographical area; The mutual interaction of factors such as climate (temperature-precipitation), topography (altitude-mountain extent), soil plays an important role. In addition, these factors also determine the ecological and geographical distribution of vegetation at micro and macro levels. In this study, geographic information systems (GIS) are used as a method and here; Digital elevation model of the basin (30x30), multi-year climate data (precipitation, temperature), Erinc climate type results, soil distribution, stand distribution, plant profiles and field photographs are the materials used in the study. By processing these data, the type and distribution of vegetation in the Goksu basin were determined. According to these findings, physical factors such as altitude and the extent of the mountains have created significant differences in the precipitation and temperature distribution of the basin. This difference was clearly observed in the Erinc climate classification results, and the south of the basin presented humid and semihumid climate characteristics, and the north presented semi-arid climate characteristics. These climatic conditions also affected the soil formation and type,causing a wide distribution of non-calcareous brown soils and non-calcareous brown forest soils in the field. As a result of all these conditions, plant species showed different vertical and spatial distribution. In the part from the south of the basin to Saimbeyli, plant species such maquis, pinus brutia, pinus nigra, Cedrus libani, Abies, Juniperus are distributed, while in the north, oak species such as oak, Bromus torhentallus, Astragalus, Thymus have been distributed. Thus, factors such as climate, topography and soil played an important role in the spread of vegetation and species in the Goksu Basin.

scholarly journals West Nile virus transmission potential in Portugal

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
José Lourenço ◽  
Sílvia C. Barros ◽  
Líbia Zé-Zé ◽  
Daniel S. C. Damineli ◽  
Marta Giovanetti ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Transmission ◽  
Molecular Evidence ◽  
Climate Data ◽  
The South ◽  
West Nile ◽  
Transmission Potential ◽  
Land Type ◽  
The North ◽  
West Nile Virus Transmission

AbstractIt is unclear whether West Nile virus (WNV) circulates endemically in Portugal. Despite the country’s adequate climate for transmission, Portugal has only reported four human WNV infections so far. We performed a review of WNV-related data (1966–2020), explored mosquito (2016–2019) and land type distributions (1992–2019), and used climate data (1981–2019) to estimate WNV transmission suitability in Portugal. Serological and molecular evidence of WNV circulation from animals and vectors was largely restricted to the south. Land type and climate-driven transmission suitability distributions, but not the distribution of WNV-capable vectors, were compatible with the North-South divide present in serological and molecular evidence of WNV circulation. Our study offers a comprehensive, data-informed perspective and review on the past epidemiology, surveillance and climate-driven transmission suitability of WNV in Portugal, highlighting the south as a subregion of importance. Given the recent WNV outbreaks across Europe, our results support a timely change towards local, active surveillance.

Impacts of climate change on net crop revenue in North and South China

2014 ◽  
Vol 6 (3) ◽  
pp. 358-378 ◽  
Author(s):  
Jinxia Wang ◽  
Jikun Huang ◽  
Lijuan Zhang ◽  
Yumin Li
Keyword(s):  
Climate Change ◽  
Climate Change Impacts ◽  
Climate Data ◽  
The South ◽  
Content Type ◽  
The North ◽  
Precipitation Variation ◽  
The Impact ◽  
North And South ◽  
Impacts Of Climate Change

Purpose – The purpose of this paper is to explore the impacts of climate change on crop net revenue by region. Particularly, the authors focus on the impact differences between north and south regions. Design/methodology/approach – The authors applied the Ricardian approach which assumes that each farmer wishes to maximize revenue subject to the exogenous conditions of their farm. The climate data are based on actual measurements in 753 national meteorological stations and the socio-economic data covers 8,405 farms across 28 provinces in China. Findings – On average, the rise of annual temperature will hurt farms both in the north or south. The impacts of climate change on both precipitation and temperatures have different seasonal impacts on producers in the north and the south of China. As a consequence, the impact on net farm revenues varies with farms in the north and the south being adversely affected (to different degrees) by a rise in the temperature, but both benefiting from an anticipated increase in rainfall. The results also reveal that irrigation is one key adaption measure to dealing with climate change. Whether in the north or south of China, increasing temperature is beneficial to irrigated farms, while for rainfed farms, higher temperature will result in a reduction in net revenues. The results also reveal that farms in the north are more vulnerable to temperature and precipitation variation than that in the south. Irrigated farms in the south are more vulnerable to precipitation variation than that in the north; but rainfed farms in the north are more vulnerable to precipitation variation than that in the south. Originality/value – Applying empirical analysis to identify the differences of climate change impacts between north and south regions will help policy makers to design reasonable adaptation policies for various regions.

scholarly journals Re-Evaluating the Climate Factor in Agricultural Land Assessment in a Changing Climate—Saskatchewan, Canada

Land ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 49
Author(s):  
Samantha Kerr ◽  
Yuliya Andreichuk ◽  
David Sauchyn
Keyword(s):  
Agricultural Land ◽  
Climate Model ◽  
Regional Climate ◽  
Arable Land ◽  
Wheat Yield ◽  
Maximum Temperature ◽  
Regression Equations ◽  
Climate Data ◽  
Climate Factor ◽  
Weather Variables

We established the statistical relationships between seasonal weather variables and average annual wheat yield (Hard Red Spring and Durum wheat: Triticum spp.) for the period of 1979–2016 for 296 rural municipalities (RMs) throughout six soil zones comprising the arable agricultural zone of Saskatchewan, Canada. Controlling climate variables were identified through Pearson’s product moment correlation analysis and used in stepwise regression to predict wheat yields in each RM. This analysis provided predictive regression equations and summary statistics at a fine spatial resolution, explaining up to 75% of the annual variance of wheat yield, in order to re-evaluate the climate factor rating in the arable land productivity model for the Saskatchewan Assessment and Management Agency (SAMA). Historical climate data (1885–2016) and Regional Climate Model (RCM) projections for the growing season (May–August) were also examined to put current climatic trends into longer-term perspective, as well as develop a better understanding of possible future climatic impacts on wheat yield in Saskatchewan. Historical trends demonstrate a decrease in maximum temperature and an increase in minimum temperature and precipitation throughout all soil zones. RCM projections also show a potential increase in temperatures and total precipitation by 5 °C and 10%, respectively. We recommended against a modification of the climate factor rating at this time because (1) any increase in wheat yield could not be attributed directly to the weather variables with the strongest trends, and (2) climate and wheat yield are changing more or less consistently across the zone of arable land, and one soil zone is not becoming more productive than another.

scholarly journals Rill Erosion and Soil Quality in Forest and Deforested Ecosystems with Different Morphological Characteristics

Resources ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 129
Author(s):  
Misagh Parhizkar ◽  
Mahmood Shabanpour ◽  
Demetrio Antonio Zema ◽  
Manuel Esteban Lucas-Borja
Keyword(s):  
Soil Quality ◽  
Quality Indicators ◽  
Prediction Models ◽  
Morphological Characteristics ◽  
Root Weight ◽  
Regression Equations ◽  
Rill Erosion ◽  
Soil Quality Indicators ◽  
The South ◽  
The North

Rill detachment capacity is a key parameter in concentrated flow erosion. Rill erosion generally turns into gully erosion with severe environmental impacts. Changes in land use and human activities can have heavy effects in rill formation, particularly in forests subject to deforestation; soil morphology plays a significant role in these effects. However, literature reports few studies about rill detachment rates and their implications on soil quality in forest and deforested soils with different morphological characteristics. To fill these gaps, this study has evaluated the rill detachment capacity (Dc) and the main soil quality indicators in three areas (upper, middle and lower slope) of forest and deforested (for 10 years) hillslopes exposed to the north and south in Northern Iran. The variations of Dc have been measured on soil samples under laboratory conditions through a flume experiment at three slope gradients (12 to 19%) and five flow rates (0.22 to 0.67 L m−1 s−1) with four replications. The large and significant (p < 0.05) difference (about 70%) detected for Dc between forest and deforested hillslopes was associated to the higher organic matter content of forest areas; as a consequence, these areas also showed higher aggregate stability, porosity, root weight density, microbial respiration and available water. In the deforested hillslopes exposed to the south, the soil erodibility was higher by 12% compared to those exposed to the north. The differences in the monitored soil quality indicators were instead less noticeable and not always significant (p < 0.05). Conversely, Dc did not significantly change (p < 0.05) among the upper, middle and lower hillslope areas investigated in this study. Simple but accurate models to predict the rill detachment capacity, erodibility and critical shear stress of soils from indicators of soil quality or the unit stream power using regression equations are suggested. Overall, the results can support land planners in prioritizing the actions for soil conservation in deforested hillslopes exposed to the south as well as in the extensive application of the proposed equations in erosion prediction models.

scholarly journals Hydrochemical Evaluation of the Tigris River from Mosul to South of Baghdad Cities, Iraq

2021 ◽  
pp. 44-58
Author(s):  
Alyaa Shakir Oleiwi ◽  
Moutaz Al-Dabbas
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Cross Sectional Study ◽  
Climate Data ◽  
The South ◽  
Cross Sectional ◽  
Climate Change Effects ◽  
The North ◽  
Tigris River

Aims of this Study: To investigate the climate change{effects in Iraq on the quality and quantity of the water of the Tigris River from {Mosul” city to South of Baghdad city.00 This paper provides a review of the observed and the predicted impacts of climate change on the water quality in the Tigris River in Iraq. Study Design: Cross-Sectional study. Place and Duration of Study: The study area is starting {from Mosul city which is located in {the north part of Iraq to the Al-Azziziyah city located in the south of Baghdad (2005-2012) . Methodology: The current study was include the available historical data which are the discharge and hydrochemical analysis includes (Ca, Mg, Na, K, Cl, SO4, HCO3, TDS,NO3, and EC) were taken from 6 stations along the Tigris’ River from Mosul to the south of Baghdad’ cities for the years 2005 to 20112. The available historical climate data’ includes (Rainfall and Temperature) for the period 1990-2012. In this paper also, used some of pervious studies and compared them with the current results. Results: The average annual flow of the Tigris River in Mosul station for the period (1990-2012) ranged between’ (193.8-906) m3/sec and for Sammarra station ranged between’ (366-977) m3/sec. Then, between south of Sammarra’city and north of Baghdad city, Canal of Dijla’joins the Tigris River has a discharge ranges between’ (9-217) m3/sec. After that, the ’Tigris River inter to Baghdad city, the discharge value range between’ (392-1173) m3/sec’and continue his flow to the south of Baghdad city and Diyala River joins it with discharge’range between (55-193) m3/sec. Finally, the Tigris River reaches to’Al-Azizziyah city station with’discharge ranges between (134-769) m3/sec. Conclusion: In general the water quality of the Tigris River are sulfates, calcium, and magnesium. But in Canal of Dijla the most dominant ion is sodium due to agricultural activities and geology of the area consist of gypsum rocks and this can be effects on water quality of Tigris River in the next station (Baghdad). In Al-Azizziyah city the sulfates, calcium, and Sodium is high level due to drainage from irrigation, industrial“and domestic activities.

scholarly journals Etude De La Vulnerabilite Aux Risques D’inondations Dans La Ville De Meknes. Apport Des Sig, Du Mnt Et Des Modeles Empiriques

2017 ◽  
Vol 13 (36) ◽  
pp. 102 ◽  
Author(s):  
Abdelaziz Rhazi ◽  
Ali Essahlaoui ◽  
Abdellah El Hmaidi ◽  
Abdelhadi El Ouali
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Geographic Information ◽  
Climate Data ◽  
The South ◽  
The North ◽  
A Priority ◽  
The City

The present study aims to assess, identify and map the risk of flooding urban in the aim of protecting the city of Meknes (center of northern Morocco) from the flooding of the Oued Boufekrane which runs along the city from the south to the north. It is carried out using the tools modeling, of empirical formulae and functions integrated into the software dedicated to the systems of Geographic Information System (GIS) and by exploiting the climate data, hydrological, topographical, geological, etc. The slopes of the watershed of the Oued Boufekrane vary approximately between 1 and 19%. They allow determining the areas and neighborhoods vulnerable to the risk of flooding with slopes not exceeding the 6%. The vulnerability to the risk of flooding which requires a priority intervention affects mainly the neighborhoods located in the southwest of the agglomeration of Meknes and along the valley of the Oued Boufekrane.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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