scholarly journals Dynamics of Evernia prunastri (L.) Ach. and Hypogymnia physodes (L.) Nyl. population structure on Tilia cordata Mill. in the flooded lime-tree forest of the Bolshaya Kokshaga river

2019 ◽  
Vol 8 (1) ◽  
pp. 110-115
Author(s):  
Yulia Gennadyevna Suetina ◽  
Sergey Mikhailovich Ivanov
Keyword(s):  
Population Structure ◽  
Life Forms ◽  
Tilia Cordata ◽  
Hypogymnia Physodes ◽  
Evernia Prunastri ◽  
Lime Tree ◽  
Young Thalli ◽  
Ontogenetic Structure ◽  
Structure Of Population ◽  
The Difference

The paper deals with perennial dynamics of the population structure of the epiphytic lichens Evernia prunastri (L.) Ach. (2008-2016) and Hypogymnia physodes (L.) Nyl. (2010-2016) with the different life forms and the ecological strategies. The research was carried out in the Mari El Republic in the flooded lime-tree forest. The authors studied the density (number of thalli on a tree) on the trunk from 0 to 1,5 meters, the size and the ontogenetic structure of population of both species of different ontogenetic states: virginile (v1, v2), potentially generative (g1v, g2v, g3v), subsenile (ss) on 17 trees of Tilia cordata. The density of E. prunastri and H. physodes population increases. These changes are more specific for E. prunastri . Thalli of E. prunastri have a bigger size than thalli of H. physodes . These differences are observed on g1v, g2v, g3v, ss thalli. The decrease of thalli size is observed for both species but the difference is more for E. prunastri . The comparison of ontogenetic spectra of populations was made according to their heterogeneity within trees. The values of the effects (the effect is the parameter of the ontogenetic spectrum of the population) decreased in 2016, which indicated a shift of the ontogenetic spectra to the left, i.e. an increase in the proportion of young thalli that can be traced in the total ontogenetic spectra of populations. At the same time, the differences between the ontogenetic spectra of the E. prunastri population are statistically significant.

scholarly journals The comparison of population structure and distribution of thalli Evernia prunastri (L.) Ach. along the trunk of Tilia cordata in a shaded floodplain lime-tree forest for 2008-2017

2021 ◽  
Vol 10 (2) ◽  
pp. 99-103
Author(s):  
Yulia Gennadjevna Suetina
Keyword(s):  
Population Density ◽  
Tilia Cordata ◽  
Epiphytic Lichens ◽  
Hypogymnia Physodes ◽  
Tree Trunk ◽  
Evernia Prunastri ◽  
North East ◽  
Lime Tree ◽  
South West ◽  
Ontogenetic Structure

The research was carried out in shaded flooded lime-tree forest on the territory of the Mari El Republic. Population density, ontogenetic structure of populations and thalli vitality of E . prunastri were explored on 19 marked trees of heart-leaved linden on different tree trunk heights (0-0,5 m, 0,5-1 m, 1-1,5 m, 1,5-2 m) and on different expositions (north, east, south, west). For the period from 2008 to 2017 an increase in the population density of E . prunastri was founded. These differences appear at the trunk height of 1,5-2 m. Thalli were not founded at the height of 0-0,5 m. No changes in the distribution of thalli by exposure in different years were revealed. The most of E . prunastri thalli grow on the northern exposure. In 2017 in the population the specimens share of v₁, v₂ and g₂v of ontogenetic states increases and the specimens share of g₁v decreases. The average vitality of E . prunastri thalli decreases, the deterioration of vitality is more pronounced among individuals in g₁v-ss ontogenetic states. An increase in the population density, a decrease in the size of the E . prunastri thalli and Hypogymnia physodes , a rejuvenation of the ontogenetic structure of the E . prunastri thalli were shown earlier for the illuminated floodplain lime forest. Similar processes in different environmental conditions and in different species indicate regular changes in the populations of epiphytic lichens, which can be caused by climate warming.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

scholarly journals Research on China's Population Structure in the New Situation

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Jingxuan Cui ◽  
Mengshuai Yin ◽  
Zerong Liu
Keyword(s):  
Population Structure ◽  
Rural Population ◽  
Regression Equation ◽  
Multiple Regression Equation ◽  
Female Ratio ◽  
Men And Women ◽  
Child Policy ◽  
Dynamic Perspective ◽  
The Difference ◽  
The Impact

To analyze the impact of the “two-child policy” on the population size and structure, first of all, the birth rate, the ratio of men and women, and the ratio of urban and rural population are used as indicators. Before and after the dispersion, then establish a PDE model, and compare it with the population predicted by the gray forecast to analyze the mitigation of the ageing of the second child policy; continue to analyze the impact of changes in the population structure on the national economy, and select the male and female ratio and the labor population The urban-rural population ratio is used as an index to establish a multiple regression equation for analysis, and a related regression equation is obtained. Finally, the future marriage problem is analyzed, considering only the difference in the number of men and women entering the marriageable period at the same time. The difference in the number of marriageable populations is analyzed through the difference in the number of men and women born at birth, focusing on a dynamic perspective.

The difference of morphological characteristics and population structure in PAO and DPAOgranular sludges

2019 ◽  
Vol 76 ◽  
pp. 388-402 ◽  
Author(s):  
Geumhee Yun ◽  
Hansaem Lee ◽  
Yongsuk Hong ◽  
Sungpyo Kim ◽  
Glen T. Daigger ◽  
...  
Keyword(s):  
Population Structure ◽  
Morphological Characteristics ◽  
The Difference

Dendroecological assessment of climate resilience of the rare and scattered forest tree species Tilia cordata Mill. in northwestern Europe

2020 ◽  
Vol 93 (5) ◽  
pp. 675-684
Author(s):  
Nicolas Latte ◽  
Philippe Taverniers ◽  
Tanguy de Jaegere ◽  
Hugues Claessens
Keyword(s):  
Climate Change ◽  
Climatic Change ◽  
Tree Ring ◽  
Tree Species ◽  
Forest Tree ◽  
Tilia Cordata ◽  
The Past ◽  
Lime Tree ◽  
Over Time ◽  
Forest Managers

Abstract To increase forest resilience to global change, forest managers are often directing forest stands towards a broader diversity of tree species. The small-leaved lime (Tilia cordata Mill.), a rare and scattered species in northwestern Europe, is a promising candidate for this purpose. Its life traits suggest a high resilience to climate change and a favourable impact on forest ecosystem services. This study used a dendroecological approach to assess how lime tree radial growth had responded to the past climatic change. First, 120 lime trees from nine sites were selected in southern Belgium based on criteria adapted to the rareness of the species. Chronology quality was assessed and resulting tree-ring series were validated at site and region levels. Second, a range of dendrochronological methods was used to analyze the changes over time in the variability and long-term trends of lime tree growth and their relation to climate during the period 1955–2016. Last, behaviour of lime trees was compared with that of beech from the same region and time period. For this purpose, the same methodology was applied to an additional beech tree-ring dataset (149 trees from 13 sites). Beech is the climax tree species of the region, but is known to be drought-sensitive and has shown weaknesses in the current climate. The quality of our tree-ring series attests that dendroecological investigation using rare and scattered species is possible, opening the way to further analysis on other such lesser-known forest tree species. The analysis showed that the small-leaved lime had been resilient to the past climatic change in multiple ways. Lime growth increased during the preceding decades despite an increased frequency and intensity of stressful climatic events. Lime growth quickly recovered in the years following the stresses. The growth–climate relationships were either stable over time or had a positive evolution. The behaviour of lime contrasted strongly with that of beech. Lime performed better than beech in every analysis. Small-leaved lime is thus a serious candidate for addressing climate change challenges in the region. It should be considered by forest managers planning to improve the sustainability and resilience of their forests, in particular in vulnerable beech stands.

scholarly journals Amplifiers of selection

2015 ◽  
Vol 471 (2181) ◽  
pp. 20150114 ◽  
Author(s):  
B. Adlam ◽  
K. Chatterjee ◽  
M. A. Nowak
Keyword(s):  
Population Structure ◽  
Probability Distribution ◽  
Initial Conditions ◽  
Large Population ◽  
Fixation Probability ◽  
Population Structures ◽  
The Difference ◽  
Large Population Limit

When a new mutant arises in a population, there is a probability it outcompetes the residents and fixes. The structure of the population can affect this fixation probability. Suppressing population structures reduce the difference between two competing variants, while amplifying population structures enhance the difference. Suppressors are ubiquitous and easy to construct, but amplifiers for the large population limit are more elusive and only a few examples have been discovered. Whether or not a population structure is an amplifier of selection depends on the probability distribution for the placement of the invading mutant. First, we prove that there exist only bounded amplifiers for adversarial placement—that is, for arbitrary initial conditions. Next, we show that the Star population structure, which is known to amplify for mutants placed uniformly at random, does not amplify for mutants that arise through reproduction and are therefore placed proportional to the temperatures of the vertices. Finally, we construct population structures that amplify for all mutational events that arise through reproduction, uniformly at random, or through some combination of the two.

Morphometry and population structure of non-harvested and harvested populations of the Japanese red coral (Paracorallium japonicum) off Amami Island, southern Japan

2012 ◽  
Vol 63 (5) ◽  
pp. 468 ◽  
Author(s):  
Nozomu Iwasaki ◽  
Toshihiko Fujita ◽  
Giorgio Bavestrello ◽  
Riccardo Cattaneo-Vietti
Keyword(s):  
Population Structure ◽  
Sustainable Management ◽  
Rest Period ◽  
Main Mode ◽  
Remotely Operated Vehicle ◽  
Red Coral ◽  
Southern Japan ◽  
Northern Pacific ◽  
The Difference ◽  
Sustainable Fishery

Precious coral harvested in the Mediterranean Sea and the northern Pacific Ocean is of commercial value yet excessive fishing has led to a serious decline in its abundance. Consequently, there is now international discussion about controlling the world trade of precious coral. To explore the possibility of a sustainable fishery of Japanese red coral (Paracorallium japonicum), the morphometry and the population structure of populations in a non-harvested area and in a harvested area were investigated using a remotely operated vehicle (ROV) off Amami Island, Southern Japan, in 2009. In the harvested population, the estimated modal ages are 10 to 20 years. In contrast, the main mode in the non-harvested population extends widely from 20 to 40 years, with a small but distinct secondary mode between 50 and 60 years. Commercially collected specimens are mainly 30–40 years old. The difference in the modes of non-harvested and harvested populations suggests that harvested populations return to the pre-fishing level after at least 10–20 years of a biological rest period. This study indicates a rotational harvest is useful for sustainable management.

scholarly journals Cognitive niche

2020 ◽  
Vol 11 (1) ◽  
pp. 64-70
Author(s):  
Đorđe Petronić ◽  
Igor Vujović
Keyword(s):  
Charles Darwin ◽  
Life Forms ◽  
Human Intelligence ◽  
Theory Of Evolution ◽  
Cognitive Niche ◽  
Human Habitat ◽  
Science Philosophy ◽  
The Origin Of Life ◽  
The Difference ◽  
Survival Mode

In a joint publication with Alfred Russell Wallace, Charles Darwin presented the theory which stated that all life forms were developed by natural selection in which the fight for survival had the effect similar to artificial intelligence applied to selective breeding. Despite a coincidence of views concerning the origin of life, these two scientists had their disagreements. Wallace argued that intelligence could have never arisen through the process of natural adaptation, but rather as a consequence of intelligent design. On the other hand, Darwin insisted that human intelligence could only be explained by the theory of evolution. This difference in point of views on the matter is a manifestation of the difference in the efforts to answer the question: "Why are people so intelligent?" In this context, the main aim of the study is to present a literature review concerning evolutionary psychology and to provide an explanation of the evolution of human intelligence. In other words, the study seeks to explain why people are able to accomplish such intellectual exploits as the ones found in mathematics, science, philosophy, law, etc., bearing in mind that such abilities or talents cannot be found in the original human habitat. The results have showed that evolutionary psychologists consider humans to be so intelligent due to the fact that they have evolved to fill the "cognitive niche". The cognitive niche is a survival mode characterized by managing the environment through mediating cognition and social cooperation.

scholarly journals PHOTOPROTECTIVE, CYTOTOXIC AND PHOTOMODIFYING ACTIVITY OF LICHEN BIOMASS NON-POLAR FRACTIONS AGAINST HUMAN KERATINOCYTE (HaCAT)

2021 ◽  
Vol 2 ◽  
pp. 29-35
Author(s):  
Volga M. Khramchankova ◽  
◽  
Matsvei V. Matveyenkau ◽  
Keyword(s):  
Ultraviolet Radiation ◽  
Ultraviolet Irradiation ◽  
Human Keratinocytes ◽  
Hexane Extract ◽  
Hypogymnia Physodes ◽  
Evernia Prunastri ◽  
Human Keratinocyte ◽  
Xanthoria Parietina ◽  
Benzene Extract

In vitro, the photoprotective, cytotoxic and photomodifying properties of hexane and benzene extracts from the widely distributed in Belarus lichens Cladonia arbuscula, Evernia prunastri, Hypogymnia physodes, Ramalina pollinaria and Xanthoria parietina in the culture of human keratinocytes (HaCAT), are estimated. It was found that these extracts are not photoprotective, they have a photomodifying effect upon irradiation of keratinocyte cultures with ultraviolet light. Hexane extract of E. prunastri and benzene extracts of R. pollinaria and H. physodes at a concentration of 2.5 μg/ml are photoprotectors that weaken the effect of ultraviolet radiation by 1.6 ÷ 1.8 times. Extracts of C. arbuscula and X. parietina are photosensitizers – they increase the toxic effect of ultraviolet radiation by 10 or more times, regardless of the concentration of the extract in the nutrient medium. Hexane and benzene extracts of C. arbuscula and H. physodes lichens are cytotoxic to the HaCAT culture. With an increase in the dose of ultraviolet irradiation of keratinocytes from zero to lethal values, the benzene extract of R. pollinaria acted as a photoprotector at a concentration of 2.5 μg / ml, and as a photosensitizer at higher concentrations. The hexane and benzene extracts of E. prunastri and H. physodes exhibited sensitizing properties that increased with an increase in the concentration of lichen extracts. C. arbuscula hexane extract and X. parietina benzene extract were the most potent photosensitizers.

scholarly journals Техногенный ландшафт как средоточие разнообразия редких видов лишайников в Центральном Черноземье

2020 ◽  
pp. 21-31
Author(s):  
Evgeniya E. Muchnik ◽  
Nikolaj I. Zolotukhin ◽  
Nikolaj I. Degtyarev
Keyword(s):  
Hypogymnia Physodes ◽  
Evernia Prunastri ◽  
Parmelia Sulcata ◽  
Pseudevernia Furfuracea ◽  
Xanthoria Parietina

Цель – первое лихенологическое обследование техногенных отвалов Михайловского горно-обогатительного комбината (Железногорский район, Курская область) с прилегающими природными и урбанизированными территориями. Материалы и методы. Сборы материалов проводились маршрутным методом в течение 2017 и 2019-2020 годов, камеральная обработка осуществлялась с применением общепринятых лихенологических методик. Идентифицированные образцы хранятся в гербариях Центрально-Черноземного заповедника им. проф. В. В. Алехина и Станции юных натуралистов г. Железногорска. Результаты и обсуждение. Выявленная лихенобиота включает 88 видов (преимущественно макролишайников, вследствие методики сбора) из 38 родов, 18 семейств. Наиболее распространенные, металл-толерантные виды: геоплезные Cladonia fimbriata, C. coniocraea, эпигеидные C. rei, C. mitis, C. cornuta, C. furcata, C. phyllophora и C. gracilis, эпифито-эпиксильные Evernia prunastri, Parmelia sulcata, Xanthoria parietina, Hypogymnia physodes и Physcia adscendens. Составлен аннотированный список в различной степени редких видов, среди которых 4 новых для Центрального Черноземья (Cladonia cervicornis, Dibaeis baeomyces, Usnea dasopoga, U. lapponica); 5 новых для Курской области (Bryoria fuscescens, Cladonia carneola, C. deformis, Melanohalea septentrionalis, Peltigera extenuata); 6 занесенных в Красную книгу Курской области (Cladonia subrangiformis, C. subulata, Peltigera praetextata, Platismatia glauca, Pseudevernia furfuracea и Usnea subfloridana); еще 5 редки в области или на более обширных территориях (Acarospora veronensis, Protoparmeliopsis muralis, Ramalina pollinaria, Trapelia coarctata, Usnea hirta). Сосредоточение значительного числа редких видов в техногенных ландшафтах, по-видимому, обусловлено рядом причин: наличием крупных выходов редкого в области и Центральном Черноземье субстрата (ожелезненного песчаника); слабой конкуренцией со стороны сосудистых растений на бедных и обогащенных металлами почвах и грунтах; ботанико-географическим положением территории; спецификой локального загрязнения среды, представленного преимущественно «кислыми» поллютантами и частицами металлов. Заключение. Отмечена приуроченность регионально редких кустистых и листоватых эпифитов из экологической группы ацидофилов к насаждениям березы в изученных техногенных ландшафтах. Предложены некоторые меры охраны выявленных редких видов лишайников.

Sign in / Sign up

Export Citation Format

Share Document