scholarly journals Climate variability and long-term expansion of peat lands in Arctic Norway during the late Pliocene (ODP Site 642, Norwegian Sea)

2015 ◽  
Vol 11 (6) ◽  
pp. 5755-5798 ◽  
Author(s):  
S. Panitz ◽  
U. Salzmann ◽  
B. Risebrobakken ◽  
S. De Schepper ◽  
M. J. Pound
Keyword(s):  
Climate Variability ◽  
Boreal Forest ◽  
Climatic Conditions ◽  
Forest Zone ◽  
Norwegian Sea ◽  
Late Pliocene ◽  
Oxygen Isotope Stage ◽  
Cool Temperate ◽  
Vegetation And Climate

Abstract. Little is known about the terrestrial response of high latitude Scandinavian vegetation to the warmer-than-present climate of the Late Pliocene (Piacenzian, 3.60–2.58 Ma). In order to assess Piacenzian terrestrial climate variability we present the first high resolution reconstruction of vegetation and climate change in northern Norway between 3.6–3.14 Ma. The reconstructions are derived from pollen assemblages in the marine sediments of ODP Hole 642B, Norwegian Sea (67° N). The palynological assemblages provide a unique record of latitudinal and altitudinal shifting of the forest boundaries, with vegetation alternating between cool temperate forest during warmer-than-present intervals, and boreal forest similar to today during cooler intervals. The northern boundary of the nemoral to boreonemoral forest zone was displaced at least 4–8° further north and warmest month temperatures were 6–14.5 °C higher than present during warm phases. Warm climatic conditions persisted during the earliest Piacenzian (ca. 3.6–3.47 Ma) with diverse cool temperate nemoral to boreonemoral forests growing in the lowlands of the Scandinavian mountains. A distinct cooling event at ca. 3.47 Ma resulted in a southward shift of vegetation boundaries, leading to the predominance of boreal forest and the development of open, low alpine environments. The cooling culminated around 3.3 Ma, coinciding with Marine Oxygen Isotope Stage (MIS) M2. Warmer climate conditions returned after ca. 3.29 Ma with higher climate variability indicated by the repeated expansion of forests and peat lands during warmer and cooler periods, respectively. Climate progressively cooled after 3.18 Ma, resembling climatic conditions during MIS M2. A high variability of Norwegian vegetation and climate changes during the Piacenzian is superimposed on a long-term cooling trend. This cooling was accompanied by an expansion of Sphagnum peat lands that potentially contributed to the decline in atmospheric CO2-concentrations at the end of the Piacenzian warm period and facilitated ice growth through positive vegetation-snow albedo feedbacks. Correlations with other Northern Hemisphere vegetation records suggest hemisphere-wide effects of climate cooling.

scholarly journals Climate variability and long-term expansion of peatlands in Arctic Norway during the late Pliocene (ODP Site 642, Norwegian Sea)

2016 ◽  
Vol 12 (4) ◽  
pp. 1043-1060 ◽  
Author(s):  
Sina Panitz ◽  
Ulrich Salzmann ◽  
Bjørg Risebrobakken ◽  
Stijn De Schepper ◽  
Matthew J. Pound
Keyword(s):  
Climate Variability ◽  
Boreal Forest ◽  
Climatic Conditions ◽  
Forest Zone ◽  
Climate Conditions ◽  
Norwegian Sea ◽  
Late Pliocene ◽  
Cool Temperate ◽  
Vegetation And Climate

Abstract. Little is known about the terrestrial response of high-latitude Scandinavian vegetation to the warmer-than-present climate of the late Pliocene (Piacenzian, 3.60–2.58 Ma). In order to assess Piacenzian terrestrial climate variability, we present the first high-resolution reconstruction of vegetation and climate change in northern Norway between 3.6 and 3.14 Ma. The reconstructions are derived from pollen assemblages in the marine sediments of ODP Hole 642B, Norwegian Sea (67° N). The palynological assemblages provide a unique record of latitudinal and altitudinal shifting of the forest boundaries, with vegetation alternating between cool temperate forest during warmer-than-present intervals and boreal forest similar to today during cooler intervals. The northern boundary of the nemoral to boreonemoral forest zone was displaced at least 4–8° further north, and warmest-month temperatures were 6–14.5 °C higher than at present during warm phases. Warm climatic conditions persisted during the earliest Piacenzian (ca. 3.6–3.47 Ma) with diverse cool temperate nemoral to boreonemoral forests growing in the lowlands of the Scandinavian mountains. A distinct cooling event at ca. 3.47 Ma resulted in a southward shift of vegetation zones, leading to the predominance of boreal forest and the development of open, low alpine environments. The cooling culminated around 3.3 Ma, coinciding with Marine Isotope Stage (MIS) M2. Warmer climate conditions returned after ca. 3.29 Ma, with higher climate variability indicated by the repeated expansion of forests and peatlands during warmer and cooler periods, respectively. Climate progressively cooled after 3.18 Ma, resembling climatic conditions during MIS M2. A high variability of Norwegian vegetation and climate changes during the Piacenzian is superimposed on a long-term cooling trend. This cooling was accompanied by an expansion of Sphagnum peatlands that potentially contributed to the decline in atmospheric CO2 concentrations at the end of the Piacenzian warm period and facilitated ice growth through positive vegetation–snow albedo feedbacks. Correlations with other Northern Hemisphere vegetation records suggest hemisphere-wide effects of climate cooling.

scholarly journals Effect of climate variability on event frequency of sorghum ergot in Australia

2003 ◽  
Vol 54 (6) ◽  
pp. 599 ◽  
Author(s):  
Enli Wang ◽  
Malcolm Ryley ◽  
Holger Meinke
Keyword(s):  
Climate Variability ◽  
Southern Oscillation ◽  
Climatic Conditions ◽  
Considerable Research ◽  
Significant Difference ◽  
Negative Effect ◽  
Claviceps Africana ◽  
Relative Risk Assessment ◽  
Resistant Genotypes

The significant effect of ergot, caused by Claviceps africana, on the Australian sorghum industry, has led to considerable research on the identification of resistant genotypes and on the climatic conditions that are conducive to ergot outbreaks. Here we show that the potential number of monthly ergot events differs strongly from year to year in accordance with ENSO (El Niño–Southern Oscillation)-related climate variability. The analysis is based on long-term weather records from 50 locations throughout the sorghum-growing areas of Australia and predicts the potential number of monthly ergot events based on phases of the Southern Oscillation Index (SOI). For a given location, we found a significant difference in the number of potential ergot events based on SOI phases in the preceding month, with a consistently positive SOI phase providing the greatest risk for the occurrence of ergot for most months and locations. This analysis provides a relative risk assessment for ergot outbreaks based on location and prevailing climatic conditions, thereby assisting in responsive decision-making to reduce the negative effect of sorghum ergot.

Paleoecology of two marine oxygen isotope stage 7 sites correlated by the Sheep Creek tephra, northwestern North America

2003 ◽  
Vol 60 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Charles E. Schweger
Keyword(s):  
Boreal Forest ◽  
Oxygen Isotope ◽  
Pollen Record ◽  
Warm Climate ◽  
Oxygen Isotope Stage ◽  
Forest Tundra ◽  
Tundra Vegetation ◽  
Shrub Tundra ◽  
Northwestern North America ◽  
Vegetation And Climate

AbstractPollen analysis at two sites, correlated by the presence of the 190,000 yr-old Sheep Creek tephra, documents fluctuations in vegetation and climate consistent with this date and indicates that the records span marine oxygen isotope stage 7 and the stage 6/7 transition. Dawson Cut, near Fairbanks, Alaska, provides a 5.2-m-long pollen record of interglacial boreal forest succeeded by shrub tundra and then forest/tundra. Ash Bend, Stewart River, central Yukon, provides a 9.5-m-long record of interglacial boreal forest succeeded by forest/tundra, shrub tundra, and herbaceous tundra. The replacement of forest at both sites by more open or tundra vegetation indicates warm interglacial conditions giving way to cold and arid climate. It is not clear whether stage 7 was warmer than the present. The warm–cool–warm climate oscillation evident at both sites may correlate to Lake Baikal substages 7a, 7b, and 7c. Sheep Creek tephra fell on forest/tundra vegetation.

Modelling of Moisture Movement in Wood during Outdoor Storage

2001 ◽  
Vol 6 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
I. Juodeikienė ◽  
A. Kajalavičius
Keyword(s):  
Experimental Data ◽  
Finite Difference ◽  
Climatic Conditions ◽  
Two Dimensional ◽  
Moisture Movement ◽  
Finite Difference Technique ◽  
Long Term Storage ◽  
Space Formulation ◽  
Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

DROUGHT OCCURRENCE UNDER LITHUANIAN CLIMATIC CONDITIONS

2015 ◽  
Author(s):  
Laima TAPARAUSKIENĖ ◽  
Veronika LUKŠEVIČIŪTĖ
Keyword(s):  
Meteorological Data ◽  
Standardized Precipitation Index ◽  
Vegetation Period ◽  
Climatic Conditions ◽  
Precipitation Record ◽  
Calculation Step ◽  
Drought Conditions ◽  
The Standardized Precipitation Index ◽  
June July

This study provides the analysis of drought conditions of vegetation period in 1982-2014 year in two Lithuanian regions: Kaunas and Telšiai. To identify drought conditions the Standardized Precipitation Index (SPI) was applied. SPI was calculated using the long-term precipitation record of 1982–2014 with in-situ meteorological data. Calculation step of SPI was taken 1 month considering only vegetation period (May, June, July, August, September). The purpose of investigation was to evaluate the humidity/aridity of vegetation period and find out the probability of droughts occurrence under Lithuanian climatic conditions. It was found out that according SPI results droughts occurred in 14.5 % of all months in Kaunas region and in 15.8 % in Telšiai region. Wet periods in Kaunas region occurred in 15.8 %, and in Telšiai region occurrence of wet periods was – 18.8 % from all evaluated months. According SPI evaluation near normal were 69.7 % of total months during period of investigation in Kaunas and respectively – 65.5 % in Telšiai. The probability for extremely dry period under Lithuania climatic conditions are pretty low – 3.0 % in middle Lithuania and 2.4 % in western part of Lithuania.

SELECTION WORK TO IMPROVE PRODUCTIVE AND BREWING QUALITIES OF SPRING BARLEY

1970 ◽  
pp. 38-40
Author(s):  
О. V. Levakova ◽  
L. М. Eroshenko ◽  
А. N. Eroshenko
Keyword(s):  
Protein Content ◽  
Spring Barley ◽  
Humus Content ◽  
Stability Index ◽  
Field Studies ◽  
Climatic Conditions ◽  
Extract Content ◽  
Labile Phosphorus ◽  
Loam Soil

The article presents and analyzes data of competitive varietal testing of promising varieties and lines of spring barley for yield and brewing qualities. Field studies were conducted in 2014–2017 on dark gray forest heavy loam soil. Agrochemical parameters are total nitrogen – 0.24%, humus content in a layer of 0-40 cm (according to Tyurin) – 5.19%, hydrolysis nitrogen – 123.5 mg / kg, salt extract pH – 4.92 mg-eq / 100g; labile phosphorus - 34.6 mg / 100g, labile potassium – 20.0 mg / 100g. The forerunner is winter wheat. Meteorological conditions in the years of research differed from each other and from the average long-term value. Barley samples were assessed by the protein content in the grain (GOST 10846-91), extract content (GOST 12130-77), weight 1000 grains (GOST 10842-89). Ecological plasticity was determined by the method proposed by E.D. Nettevich, A.I. Morgunov and M.I. Maksimenko, stability index (Ľ) by A. A. Gryaznov, indicator of stability level (Puss) by E. D. Nettevich and A. I. Morgunov. The main measure for assessing quality indicators is protein content. Many other biochemical and technological features of grain depend on its level. The experimental data convincingly testify to the significant influence of the soil and climatic conditions on the yield and, especially, on the brewing qualities of barley in the conditions of the Central Region of the Nonchernozem Zone. According to the studied traits, new valuable varieties Nadezhny, Sir, Noble and selection lines 141 / 1-09 h 746, 23 / 1-10 h 784, distinguished by high adaptability and resistance to adverse environmental factors, have been identified.

Less Rain and More Heat”: Smallholders’ Perception and Climate Change Adaptation Strategies in Tropical Environments

2019 ◽  
pp. 77-104 ◽  
Author(s):  
Karla Diana Infante Ramírez ◽  
Ana Minerva Arce Ibarra
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Tropical Forest ◽  
Climate Change Adaptation ◽  
Coastal Zone ◽  
Weather Forecasting ◽  
Adaptation Strategies ◽  
Seasonal Migration ◽  
Forest Zone ◽  
Climate Change Adaptation Strategies

The main objective of this study was to analyze local perceptions of climate variability and the different adaptation strategies of four communities in the southern Yucatán Peninsula, using the Social-Ecological System (SES) approach. Four SESs were considered: two in the coastal zone and two in the tropical forest zone. Data were collected using different qualitative methodological tools (interviews, participant observation, and focal groups) and the information collected from each site was triangulated. In all four sites, changes in climate variability were perceived as “less rain and more heat”. In the tropical forest (or Maya) zone, an ancestral indigenous weather forecasting system, known as “Xook k’íin” (or “las cabañuelas”), was recorded and the main activity affected by climate variability was found to be slash-and burn farming or the milpa. In the coastal zone, the main activities affected are fishing and tourism. In all the cases analyzed, local climate change adaptation strategies include undertaking alternative work, and changing the calendar of daily, seasonal and annual labor and seasonal migration. The population of all four SESs displayed concern and uncertainty as regards dealing with these changes and possible changes in the future.

scholarly journals Long-term changes of river discharge regime in Latvia

2008 ◽  
Vol 39 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Maris Klavins ◽  
Valery Rodinov
Keyword(s):  
Climate Variability ◽  
River Discharge ◽  
Water Resource Management ◽  
Regional Climate ◽  
Hydrological Regime ◽  
High Water ◽  
Regime Changes ◽  
Long Term Changes ◽  
Discharge Regime

The study of changes in river discharge is important for regional climate variability characterization and for development of an efficient water resource management system. The hydrological regime of rivers and their long-term changes in Latvia were investigated. Four major types of river hydrological regimes, which depend on climatic and physicogeographic factors, were characterized. These factors are linked to the changes observed in river discharge. Periodic oscillations of discharge, and low- and high-water flow years are common for the major rivers in Latvia. A main frequency of river discharge regime changes of about 20 and 13 years was estimated for the studied rivers. A significant impact of climate variability on the river discharge regime has been found.

scholarly journals Creating and Characterisation of New Red Clover Variety ‘Jancis’/ Sarkanâ Âboliòa Ðíirnes ‘Jancis’ Izveidoðana Un Tâs Raksturojums

2014 ◽  
Vol 68 (3-4) ◽  
pp. 180-183
Author(s):  
Biruta Jansone ◽  
Sarmīte Rancāne ◽  
Pēteris Bērziņš ◽  
Aldis Jansons
Keyword(s):  
Seed Yield ◽  
Red Clover ◽  
Climatic Conditions ◽  
Family Selection ◽  
High Dry Matter ◽  
Bright Pink ◽  
Long Stem ◽  
Dark Green ◽  
High Seed Yield

Abstract The aim of this work was to develop a red clover variety adapted to agro-climatic conditions of Latvia, suitable for different requirements of forage producers, resistant to most widespread diseases and producing high seed yield annually. Medium late ripening diploid red clover variety ‘Jancis’ was created at the LLU Research Institute of Agriculture in long-term work carried out since 1985. After free pollination of best samples of red clover collections from the VIR (St. Petersburg), individual and family selection among hybrids were carried out for approximately 20 years. Finally, best breeding line Nr. 43047 was registered as a variety ‘Jancis’. The variety is characterised by good winter hardiness, high dry matter yield (10-12 t·ha-1) and good persistence in the sward - up to 3-4 years. The variety is characterised by a long stem (90-110 cm) with 8-9 internodes, dark green leaves with a distinctive brighter picture, medium length and width of medial leaflet, and bright pink flower heads. ‘Jancis’ has stable annual seed yield in the conditions of Latvia; under favourable conditions reaching 500- 600 kg·ha-1 seeds. Since 2010, the variety ‘Jancis’ has been included in the common Latvian and EU Plant Variety Catalogue.

Sign in / Sign up

Export Citation Format

Share Document