Electrophoretic study of enzymes from cereal aphid populations. V. Spatial and temporal genetic similarity of holocyclic populations of the bird-cherry oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), in Britain

1988 ◽  
Vol 78 (2) ◽  
pp. 241-249 ◽  
Author(s):  
H. D. Loxdale ◽  
C. P Brookes
Keyword(s):  
Allelic Variation ◽  
Rhopalosiphum Padi ◽  
Climatic Conditions ◽  
Population Bottlenecks ◽  
The South ◽  
Cereal Aphid ◽  
Electrophoretic Study ◽  
The North ◽  
Genotype Frequencies

AbstractLarge colonies of holocyclic Rhopalosiphum padi (L.) were sampled in May-June in 1985 and 1986 from the principal host, Prunus padus, in various parts of Britain, mainly in the south-east. They were tested electrophoretically using nine enzymes representing 14 putative genetic loci. Only two loci (14%) were polymorphic (GOT, glutamate-oxaloacetate transaminase, and SORDH, sorbitol dehydrogenase), the remainder being monomorphic. Allele and genotype frequencies at each locus were generally similar both spatially and temporally, and genotype frequencies were close to Hardy-Weinberg expectations. The low level of genetic variability may reflect population bottlenecks which have purged most of the variation and which have been imposed by the distribution of P. padus, especially in the south of Britain where the tree is generally scarce. In addition, it is probable that adverse climatic conditions directly affect winter survival of anholocyclic populations of the aphid and thus also reduce variability. In the long term, such bottlenecks would tend to preclude the maintenance of effectively neutral enzyme variants that arise within populations. The similarity of allele and genotype frequencies may reflect the highly migratory behaviour of R. padi. Thus, in southern Britain, where P. padus is generally much rarer in comparison with the north of the country, R. padi inter-population gene flow is still sufficient to alleviate the influences of genetic drift and possible directional selection on the allelic variation that remains.

scholarly journals TRAPPED BY NATURE: PROVINCIAL GRAIN YIELDS IN SPAIN IN THE MID 18TH CENTURY

2013 ◽  
Vol 31 (3) ◽  
pp. 359-386 ◽  
Author(s):  
Carlos Santiago-Caballero
Keyword(s):  
Western Europe ◽  
18Th Century ◽  
Climatic Conditions ◽  
The South ◽  
Grain Yields ◽  
The North ◽  
The World ◽  
Agricultural Regions ◽  
North Western

ABSTRACTThis paper estimates original yields for five grains in thirty-three provinces of Spain in the mid-18th century. We observe a strong heterogeneity between the provinces with yields being considerably higher in the north of the country than in the south-east. Although average yields in Spain were below those in other countries of north-western Europe, the provinces in the north achieved yields not far behind the most advanced agricultural regions of the world. The heterogeneity of yields across Spain can be explained by the different climatic conditions in each province. Although all the provinces improved their yields in the long term, the differences between the provinces remained stable until the modernisation of Spanish agriculture around the mid-20th century.

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.

scholarly journals Qualified temperature, salinity and dissolved oxygen climatologies in a changing Adriatic Sea

2014 ◽  
Vol 11 (1) ◽  
pp. 331-390
Author(s):  
M. Lipizer ◽  
E. Partescano ◽  
A. Rabitti ◽  
A. Giorgetti ◽  
A. Crise
Keyword(s):  
Dissolved Oxygen ◽  
Adriatic Sea ◽  
Eastern Mediterranean ◽  
Temporal Stability ◽  
The South ◽  
The North ◽  
Synthetic Temperature ◽  
Oxygen Utilisation ◽  
Oxygen Minimum

Abstract. An updated climatology, based on a comprehensive dataset (1911–2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature–Salinity diagram intercomparison. The concept of Climatology–Observation Misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C), a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911–1914, with an increase of +0.018 decade−1 since the late 1940s) and warmer (+0.54 °C since 1911–1914), even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L−1 since 1911–1914, with a constant increase of +0.2 mL L−1 decade−1 after the 1970s).

Methodologies for Evaluating and Qualifying External Pipeline Coatings for Northern Pipelines

2006 ◽  
Author(s):  
S. Papavinasam ◽  
A. Doiron ◽  
T. Panneerselvam ◽  
Y. Lafrenie`re ◽  
M. Attard ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Limited Data ◽  
The North

The design of coatings must be adequate to protect pipelines under long-term, severe environmental conditions, including the extreme climatic conditions that will apply in the North before the pipe is installed and operation begins. Practices and standardised methodologies for evaluating and qualifying pipeline coatings for application in northern pipelines are discussed. Results from laboratory and field experiments, carried out under the conditions to which coatings will be exposed during construction, are presented. Based on 1-year laboratory experiments in which samples were exposed to temperatures as low as −45°C and limited data from the field experiments, it is concluded that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately cover evaluation of coatings for northern pipelines. However, in order to evaluate the effects of low-temperatures, the specimens should be exposed for at least 4 months. Coatings qualified by CSA Z245.21 (System B1 and B2) are less affected from exposure to low-temperatures than those qualified by CSA Z245.21 (System A1) and CSA Z245.20.

Reconstructing crop yield variability in Finland: Long-term perspective of the cultivation history on the agricultural periphery since ad 760

The Holocene ◽  
2016 ◽  
Vol 27 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Heli Huhtamaa ◽  
Samuli Helama
Keyword(s):  
Crop Production ◽  
Wide Spectrum ◽  
Climatic Conditions ◽  
Yield Ratio ◽  
Study Region ◽  
Crop Cultivation ◽  
The North ◽  
Long Run ◽  
High Yields

Lack of documentation on past harvest fluctuations limits the exploration of long-term trends in crop production and agricultural adaptation strategies. A long-term perspective is needed, however, to understand the wide spectrum of potential human responses to environment and climate change. Therefore, we used tree-ring density series as proxy data to reconstruct climate-mediated yield ratio (harvested grain in relation to sown) in central and northern Finland over the period ad 760–2000. The reconstruction explains 50% of the variance in recorded yield ratio variability over the calibration period (ad 1866–1921). The reconstruction illustrated several intervals of increased and reduced yield ratio over the past 13 centuries. The long-term development of the agricultural prerequisites is characterized by distinct intervals defined statistically as ad 760–1106 (highest yield ratios), 1107–1451, 1452–1694, 1695–1911 (lowest yield ratios) and 1912 onwards. The results provide insight into the establishment and development of crop cultivation in the agricultural margin. The reconstruction suggests that continuous crop cultivation was established in the study region during a favourable period of climatic conditions supporting high yields. Thereafter, the climate-mediated yield ratio declined in the long run until the turn of the 20th century. Periods of agricultural transformations, those previously demonstrated in pollen data and historical documents, followed the onsets of the low yield ratio phases indicated by our reconstruction. Thus, we suggest that ever since the establishment of crop cultivation, climate can be considered as an important factor contributing to the development of the agricultural history in the north.

scholarly journals Potash regime for restoration of disturbed lands in the Far North

2020 ◽  
Vol 215 ◽  
pp. 03006
Author(s):  
Anatoly Iglovikov
Keyword(s):  
Vegetation Cover ◽  
Industrial Development ◽  
Anthropogenic Impacts ◽  
Climatic Conditions ◽  
Perennial Grasses ◽  
Low Fertility ◽  
Far North ◽  
The North ◽  
Disturbed Soils

Disturbed soils of the Far North, underlain by permafrost, have extremely low fertility and were formed according to natural and climatic conditions. These soils and the vegetation cover formed on them are very vulnerable to destructive anthropogenic impacts associated with the industrial development of the North. To restore vegetation cover, agrotechnical techniques are used, including the use of various fertilizers. This article will address issues related to changes in the content of potassium in various agricultural techniques at the biological stage of recultivation in the Far North. Agromeliorative techniques increased the accumulation of potassium in the herbage, therefore, perennial grasses consume a large amount of potassium, strengthening their ecological plasticity. It is established that agromeliorative techniques play a crucial role in providing long-term grasses with available potassium. Potassium is consumed by perennial herbs throughout life. This fact should be taken into account when determining the rates of potash fertilization to maintain a stable herbage at the biological stage of reclamation and accelerate the restoration of natural cover.

scholarly journals Analysis and revision of the Miocene boreal faunae of bivalve mollusks of the South Sakhalin

2020 ◽  
Author(s):  
В.Д. ХУДИК ◽  
Ю.Д. ЗАХАРОВ
Keyword(s):  
Japan Sea ◽  
Climatic Conditions ◽  
Bivalve Mollusks ◽  
The South ◽  
The North ◽  
Initial Stage ◽  
The Japan Sea ◽  
South Sakhalin ◽  
Early Neogene ◽  
Climatic Cooling

Приведены результаты изучения остатков фаун двустворчатых моллюсков из миоценовых отложений Южного Сахалина. Их анализ позволил выделить три бореальных комплекса моллюсков: невельский, раннечеховский и курасийский, фиксирующие периоды похолодания климата в миоцене региона. Изучение неогеновых представителей родов Lucinoma и Mya позволило обозначить среди них ряд таксонов, имеющих стратиграфическое значение. Установленное присутствие тепловодных двустворок в фаунах позднечеховского времени Южного Сахалина, очевидно, отражает собой начальный этап тенденции нарастающего потепления климата в миоцене региона с климатическим оптимумом в верхнедуйско-сертунайское время. Высказывается следующее мнение: неустойчивые климатические условия в позднем палеогене – раннем неогене северной части Япономорского региона могли быть основной причиной возникновения здесь одного из мощных центров эволюции морских малакофаун бореальных районов северной Пацифики. The results on the studying of the faunae of bivalve mollusks remains from miocene deposits of the South Sakhalin are presented. The analysis of the last ones allowed distinguishing the following three boreal assemblages of mollusks: Nevelskiy, early Chekhovskiy and Kurasiiskiy, recording the period of climatic cooling in miocene of the region. Studying of Neogene representatives of Lucinoma and Mya generas allowed identifying some taxa among them which have stratigraphic significance. The detected presence of warm water bivalves in the faunae of the late Chekhovsky time of the South Sakhalin appears to reflect the initial stage of the tendency of the intensifying climate warming happened during miocene, with climatic optimum during the Verkhneduysky – Sertunaysky times. An opinion is expressed that the unstable climatic conditions in the northern part of the Japan Sea region during late Paleogene – early Neogene could have been the main reason for originating of one of the high-potential centers of evolution of the marine malacofaunae of boreal regions of the North Pacific.

scholarly journals Reanalysis of 47 Years of Climate in the French Alps (1958–2005): Climatology and Trends for Snow Cover

2009 ◽  
Vol 48 (12) ◽  
pp. 2487-2512 ◽  
Author(s):  
Yves Durand ◽  
Gérald Giraud ◽  
Martin Laternser ◽  
Pierre Etchevers ◽  
Laurent Mérindol ◽  
...  
Keyword(s):  
Snow Cover ◽  
Snow Depth ◽  
Numerical Models ◽  
High Elevation ◽  
Climatic Conditions ◽  
Spatial And Temporal Variability ◽  
The South ◽  
French Alps ◽  
Mountainous Regions ◽  
The North

Abstract Since the early 1990s, Météo-France has used an automatic system combining three numerical models to simulate meteorological parameters, snow cover stratigraphy, and avalanche risk at various altitudes, aspects, and slopes for a number of mountainous regions (massifs) in the French Alps and the Pyrenees. This Système d’Analyse Fournissant des Renseignements Atmosphériques à la Neige (SAFRAN)–Crocus–Modèle Expert de Prévision du Risque d’Avalanche (MEPRA) model chain (SCM), usually applied to operational daily avalanche forecasting, is here used for retrospective snow and climate analysis. For this study, the SCM chain used both meteorological observations and guess fields mainly issued from the newly reanalyzed atmospheric model 40-yr ECMWF Re-Analysis (ERA-40) data and ran on an hourly basis over a period starting in the winter of 1958/59 until recent past winters. Snow observations were finally used for validation, and the results presented here concern only the main climatic features of the alpine modeled snowfields at different spatial and temporal scales. The main results obtained confirm the very significant spatial and temporal variability of the modeled snowfields with regard to certain key parameters such as those describing ground coverage or snow depth. Snow patterns in the French Alps are characterized by a marked declining gradient from the northwestern foothills to the southeastern interior regions. This applies mainly to both depths and durations, which exhibit a maximal latitudinal variation at 1500 m of about 60 days, decreasing strongly with the altitude. Enhanced at low elevations, snow depth shows a mainly negative temporal variation over the study period, especially in the north and during late winters, while the south exhibits more smoothed features. The number of days with snow on the ground shows also a significant general signal of decrease at low and midelevation, but this signal is weaker in the south than in the north and less visible at high elevation. Even if a statistically significant test cannot be performed for all elevations and areas, the temporal decrease is present in all the studied quantities. Concerning snow duration, this general decrease can also be interpreted as a sharp variation of the mean values at the end of the 1980s, inducing a step effect in its time series rather than a constant negative temporal trend. The results have also been interpreted in terms of potential for a viable ski industry, especially in the southern areas, and for different changing climatic conditions. Presently, French downhill ski resorts are economically viable from a range of about 1200 m MSL in the northern foothills to 2000 m in the south, but future prospects are uncertain. In addition, no clear and direct relationship between the North Atlantic Oscillation (NAO) or the ENSO indexes and the studied snow parameters could be established in this study.

MORPHODYNAMICS OF THE SHORES OF THE VISTULA SPIT (THE BALTIC SEA) IN A PERIOD OF 2002-2015 BY RESULTS OF IN-SITU MEASUREMENTS

2017 ◽  
Author(s):  
Valentina Bobykina ◽  
Valentina Bobykina ◽  
Boris Chubarenko ◽  
Boris Chubarenko ◽  
Konstantin Karmanov ◽  
...  
Keyword(s):  
Erosion Rate ◽  
The South ◽  
The Baltic Sea ◽  
The North ◽  
Quantitative Characteristics ◽  
The Subject ◽  
The Baltic ◽  
First Time

For the first time, the quantitative characteristics of the Vistula Spit shore dynamics based on the ground-based monitoring data for 2002-2015 were presented. On the sea shore, 3 sections can be distinguished by the direction of coastal processes, i.e. the stable section to the north of the Strait of Baltiysk, the eroded 4-km section to the south of the Strait of Baltiysk, with maximum erosion rate up to 2 m/year; in the remaining area of the Spit (21 km) to the Polish border there is an alternation of stable, eroded and accumulative areas. Since 2011, a steady erosion (in the stable segments of the third section) and general weakening of the erosion rate (in the second section) have been recorded. 50% of the length of the lagoon shore was the subject to annual active erosion (0.2 - 1.4 m/year). The beaches of the sea and lagoon shores of the Vistula Spit were mainly composed of medium sands. The alongshore variability in particle size distribution on the sea and lagoon shores (according to the 2015 survey data) actually fail to correlate with long-term dynamic processes, with the exception of the steadily eroded 4-kilometer area on the sea coast to the south of the Strait of Baltiysk. Variations in the composition of sediment along the shore on the shoreline are most likely associated with the results of the latest wave processing (or storm processing and eolian transport in the case of an average beach sample).

Long-Term Interactions between Society and Ecology

2021 ◽  
pp. 107-148
Author(s):  
Tyler Franconi ◽  
Chris Gosden
Keyword(s):  
Soil Erosion ◽  
River Basins ◽  
Roman Period ◽  
The South ◽  
The North ◽  
Forested Landscapes ◽  
History Of ◽  
Human Use

The clearance history of England is reviewed looking first at what can be reconstructed of the patterns of forest and clearance across the country. A broad distinction is seen between more forested landscapes in the north and west, with greater clearance in the south and east. The forests of the north may have seen managed grazing, rather than being wild wood. From the start of the Roman period, the north was cleared as well, creating greater similarity across the country as a whole. We also look at the history of soil erosion, which is linked to clearance. We end by comparing two river basins—the Thames and the Eden—which have contrasting ecologies, topologies, and histories of human use.

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