scholarly journals Distribution and ecological segregation on regional and microgeographic scales of the diploidCentaurea asperaL., the tetraploidC. seridisL., and their triploid hybrids (Compositae)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5209 ◽  
Author(s):  
Alfonso Garmendia ◽  
Hugo Merle ◽  
Pablo Ruiz ◽  
Maria Ferriol
Keyword(s):  
Anthropogenic Disturbance ◽  
Large Scale ◽  
Latitudinal Gradient ◽  
Soil Parameters ◽  
Fine Scale ◽  
Contact Zones ◽  
Ecological Requirements ◽  
Adaptive Processes ◽  
Sympatric Cytotypes

Although polyploidy is considered a ubiquitous process in plants, the establishment of new polyploid species may be hindered by ecological competition with parental diploid taxa. In such cases, the adaptive processes that result in the ecological divergence of diploids and polyploids can lead to their co-existence. In contrast, non-adaptive processes can lead to the co-existence of diploids and polyploids or to differentiated distributions, particularly when the minority cytotype disadvantage effect comes into play. Although large-scale studies of cytotype distributions have been widely conducted, the segregation of sympatric cytotypes on fine scales has been poorly studied. We analysed the spatial distribution and ecological requirements of the tetraploidCentaurea seridisand the diploidCentaurea asperain east Spain on a large scale, and also microspatially in contact zones where both species hybridise and give rise to sterile triploid hybrids. On the fine scale, the position of eachCentaureaindividual was recorded along with soil parameters, accompanying species cover and plant richness. On the east Spanish coast, a slight latitudinal gradient was found. TetraploidC. seridisindividuals were located northerly and diploidC. asperaindividuals southerly. Tetraploids were found only in the habitats with strong anthropogenic disturbance. In disturbed locations with well-developed semi-fixed or fixed dunes, diploids and tetraploids could co-exist and hybridise. However, on a fine scale, although taxa were spatially segregated in contact zones, they were not ecologically differentiated. This finding suggests the existence of non-adaptive processes that have led to their co-existence. Triploid hybrids were closer to diploid allogamous mothers (C. aspera) than to tetraploid autogamous fathers (C. seridis). This may result in a better ability to compete for space in the tetraploid minor cytotype, which might facilitate its long-term persistence.

A network for monitoring terrestrial ecosystems along a latitudinal gradient in Continental Antarctica

2006 ◽  
Vol 18 (4) ◽  
pp. 549-560 ◽  
Author(s):  
Nicoletta Cannone
Keyword(s):  
Climate Change ◽  
Latitudinal Gradient ◽  
Terrestrial Ecosystems ◽  
Permanent Plots ◽  
Ecological Requirements ◽  
Victoria Land ◽  
Starting Point ◽  
Continental Antarctica ◽  
The Impact

A network for monitoring change in the vegetation communities to assess the impact of future climate changes was established in Victoria Land (Continental Antarctica) in 2002 and 2003. The network is within the framework of the SCAR project RiSCC (Regional Sensitivity to Climate Change in Antarctic terrestrial and limnetic ecosystems), and in cooperation with LGP (Latitudinal Gradient Project) assessing how ecosystem biodiversity and structure may change with latitude and with climate change. The network is composed of 19 permanent plots at nine sites along a latitudinal gradient from Apostrophe Island (73°30′S, 167°50′E) to Granite Harbour (77°00′S, 162°26′E), with a main coastal transect and three subtransects inland from the coast. The sites are representative of the most frequent environmental conditions and the most widespread communities occurring in Continental Antarctica and in Victoria Land. The selected communities show different ecological requirements and have different potential sensitivities to climate change. The vegetation of each plot was described using the RiSCC research protocol, developed originally in the Maritime Antarctic and here adapted, for plot size, to Continental Antarctica. This paper characterizes the vegetation at the sites as the starting point of the long term monitoring.

scholarly journals Paleontological methods in environmental science

1992 ◽  
Vol 6 ◽  
pp. 40-40
Author(s):  
Grace S. Brush ◽  
Humaira Khan
Keyword(s):  
Water Quality ◽  
Environmental Conditions ◽  
Human Disturbance ◽  
Large Scale ◽  
Environmental Changes ◽  
Nitrogen And Phosphorus ◽  
Ecological Requirements ◽  
Inorganic Substances ◽  
Stratigraphic Record

Long term environmental changes, induced both by natural and anthropogenic causes, cannot be assessed by looking solely at historical records of temperature, rainfall, water quality, etc. Frequently, such records are nonexistent. Where they do exist, they are often too short to be of much use. However, sediments contain a stratigraphic record of environmental change that allows comparison of the historic period influenced largely by humans, with prehistoric time when climate was the major determinant of environmental conditions.The stratigraphic record contains various fossilized organic materials which reflect environmental conditions at the time of the their deposition. Most abundant are pollen and spores of aquatic and terrestrial plants. Correspondence between pollen assemblages and vegetation has been found in all parts of the world. Therefore stratigraphic changes in pollen taxa reveal much information regarding the vegetational history of a region. Knowledge of the ecological requirements of various taxa can then be used to infer past climatic conditions. For example, dominance of Juglans (walnut) pollen indicates wet conditions while abundance of Pteridium (bracken fern) spores is an indicator of fire, suggesting drier conditions. Pollen can also be used to trace human disturbance to the environment. Sharp increases in the pollen of Ambrosia (ragweed) in sediment cores indicate large scale land clearance by man.Seeds preserved in sediments provide another measure of temporal vegetational change. Generally, seeds are not dispersed far from the parent plant; hence they provide a more local record of vegetation than pollen. A decrease in seeds of aquatic plants and increase in seeds of higher ground taxa when accompanied by increased sedimentation rates is an indicator of infilling of an aquatic environment. If unaccompanied by increased sedimentation, the change more likely represents lowering of sea level. Disappearance of seeds of taxa sensitive to turbidity and eutrophication provide another long term record of human disturbance.Distributions of diatoms are affected by temperature, salinity, oxygen, light availability and nutrient levels in the water. Therefore changes in diatom species preserved in the sediments can be used as indicators of climate, turbidity, anoxia and eutrophication in aquatic ecosystems.Many inorganic substances preserved in sediments also provide a long term record of changes in the environment. Nitrogen and phosphorus can be measured in cores and used as a surrogate record of water quality in lakes and estuaries. Sharp increases in sedimentary accumulation of metals record wastewater discharge and fuel emissions, related to human activity.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Computer Analyses in Preventive Health Research

1967 ◽  
Vol 06 (01) ◽  
pp. 8-14 ◽  
Author(s):  
M. F. Collen
Keyword(s):  
Medical Research ◽  
Preventive Medicine ◽  
Health Research ◽  
Large Scale ◽  
Preventive Health ◽  
New Era ◽  
Large Numbers ◽  
Normal Test ◽  
Computer Analyses

The utilization of an automated multitest laboratory as a data acquisition center and of a computer for trie data processing and analysis permits large scale preventive medical research previously not feasible. Normal test values are easily generated for the particular population studied. Long-term epidemiological research on large numbers of persons becomes practical. It is our belief that the advent of automation and computers has introduced a new era of preventive medicine.

(A review) Atlas of especially protected natural areas of Saint Petersburg / Ed. in chief V. N. Khramtsov, T. V. Kovaleva, N. Yu. Natsvaladze. St. Petersburg, 2013. 176 p.

2014 ◽  
pp. 124-129
Author(s):  
Z. V. Karamysheva
Keyword(s):  
Protected Areas ◽  
Large Scale ◽  
Natural Areas ◽  
Natural Protected Areas ◽  
Saint Petersburg ◽  
Natural Processes ◽  
Original Illustrations ◽  
Vegetation Maps ◽  
Protected Natural Areas

The review contains detailed description of the «Atlas of especially protected natural areas of Saint Petersburg» published in 2013. This publication presents the results of long-term studies of 12 natural protected areas made by a large research team in the years from 2002 to 2013 (see References). The Atlas contains a large number of the historical maps, new satellite images, the original illustrations, detailed texts on the nature of protected areas, summary tables of rare species of vascular plants, fungi and vertebrates recorded in these areas. Special attention is paid to the principles of thematic large-scale mapping. The landscape maps, the vegetation maps as well as the maps of natural processes in landscapes are included. Reviewed Atlas deserves the highest praise.

Etude de l'aménagement d'une forêt classée au Mali avec la participation des populations riveraines - Données du problème et éléments de méthodologie | A Study of the Management of a State-Owned Forest in Mali with the Participation of the Population Living nearby - Issue under Investigation and Elements of Methodology

2000 ◽  
Vol 151 (3) ◽  
pp. 80-83
Author(s):  
Pascal Schneider ◽  
Jean-Pierre Sorg
Keyword(s):  
Natural Resources ◽  
Research Methodology ◽  
Large Scale ◽  
Environmental Context ◽  
Forest Resources ◽  
The State ◽  
Commercial Use ◽  
Economic Context ◽  
The People

In and around the state-owned forest of Farako in the region of Sikasso, Mali, a large-scale study focused on finding a compromise allowing the existential and legitimate needs of the population to be met and at the same time conserving the forest resources in the long term. The first step in research was to sketch out the rural socio-economic context and determine the needs for natural resources for autoconsumption and commercial use as well as the demand for non-material forest services. Simultaneously, the environmental context of the forest and the resources available were evaluated by means of inventories with regard to quality and quantity. According to an in-depth comparison between demand and potential, there is a differentiated view of the suitability of the forest to meet the needs of the people living nearby. Propositions for a multipurpose management of the forest were drawn up. This contribution deals with some basic elements of research methodology as well as with results of the study.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

A Perspective On The Impact of COVID-19 Pandemic in Basic Science Research and its Future implications

Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Yam Nath Paudel ◽  
Efthalia Angelopoulou ◽  
Bhupendra Raj Giri ◽  
Christina Piperi ◽  
Iekhsan Othman ◽  
...  
Keyword(s):  
Basic Science ◽  
Large Scale ◽  
Preventive Measure ◽  
Science Research ◽  
Research Institutes ◽  
Basic Science Research ◽  
Long Term Consequences ◽  
Long Term Impact ◽  
The Impact

: COVID-19 has emerged as a devastating pandemic of the century that the current generations have ever experienced. The COVID-19 pandemic has infected more than 12 million people around the globe and 0.5 million people have succumbed to death. Due to the lack of effective vaccines against the COVID-19, several nations throughout the globe has imposed a lock-down as a preventive measure to lower the spread of COVID-19 infection. As a result of lock-down most of the universities and research institutes has witnessed a long pause in basic science research ever. Much has been talked about the long-term impact of COVID-19 in economy, tourism, public health, small and large-scale business of several kind. However, the long-term implication of these research lab shutdown and its impact in the basic science research has not been much focused. Herein, we provide a perspective that portrays a common problem of all the basic science researchers throughout the globe and its long-term consequences.

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