fluctuating asymmetry
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2021 ◽  
Vol 6 (48) ◽  
pp. 30-30
Author(s):  
Irina Andreeva ◽  
◽  
Dmitry Morev ◽  
Evgeny Taller ◽  
Ivan Vasenev

The article presents the results of a comparative environmental assessment of the quality of the environment in the central and outlying zones of two forest parks, contrasting in area, types and magnitude of anthropogenic load, - the Experimental Forest Station and the Dubki Culture and Recreation Park, located in the Timiryazevsky district of Moscow. The quality of the environment in the undisturbed forest biocenosis in the center of the Experimental Forest Station corresponded to the quality of the environment in the rural areas of the Moscow Region, while the environmental situation in the outlying zones of both forest parks bordering various urban infrastructure facilities deviated to varying degrees from the conditional norm. The worst indicators of the environmental quality and forest stand conditions were noted in the recreational zones located at the III-IV stage of digression, as well as in the zones bordering the roads, within which the degree of fluctuating asymmetry of birch leaves was suspended and the cellulolytic activity of the soil was 1.5-2.5 times lower than the background. The combination of recreational and transport loads reduced the quality of the environment in the Dubki park to a critical level. Keywords: CITY FOREST, BORDERLAND, ANTHROPOGENIC LOAD, POLLUTION, RECREATION, DEGRADATION, FLUCTUATING ASYMMETRY, CELLULOLYTIC ACTIVITY, APPLICATION METHOD, AIRBORNE POLLUTION, SNOW COVER


2021 ◽  
pp. 105199
Author(s):  
Ana E. Gutiérrez-Cabrera ◽  
Raúl Badillo Montaño ◽  
Lorena González ◽  
Sandra M. Ospina-Garcés ◽  
Alex Córdoba-Aguilar

2021 ◽  
Vol 48 (9) ◽  
pp. 1609-1622
Author(s):  
V. Yu. Kovaleva ◽  
A. A. Pozdnyakov ◽  
Yu. N. Litvinov ◽  
V. M. Efimov

Author(s):  
Vladimir V. Zvyagintsev ◽  
Olga Yu. Zvyagintseva ◽  
Vadim K. Chernyshov

Introduction. The paper presents the results of the studies on assessing the quality of the aquatic ecosystem of a lake located within the city. The European perch (Perca fluviatilis L.) and the Gibel carp (Carassius gibelio) were used as an indicator for determining the quality of the aquatic ecosystem by the method of fluctuating asymmetry. Problem Statement. The aim of the work was to conduct monitoring with the subsequent assessment of the quality of the ecosystem of the city lake using the method of fluctuating asymmetry (hereinafter FA). Theoretical and Practical Part. The quality of the urban lake aquatic ecosystem was assessed using the FA method (indicators: the European perch (Perca fluviatilis L.), 1758 and the Gibel carp (Carassius auratus Bloch), 1783). To identify the reasons for the high PFA values, a chemical analysis (in an accredited laboratory) of the gills of the Gibel carp for heavy metals was performed. Conclusions. As a result of the research, the FA indicators values for these indicators were obtained. According to the results of a laboratory study of the content of heavy metals in the gill arches of the Gibel carp, an excess of the maximum permissible concentration of 8 out of 10 analyzed elements was revealed. It has been established that the ecosystem of the city lake Kenon is experiencing a significant anthropogenic load (5 points — the critical quality of the aquatic environment) and it continues to increase towards the deterioration of the habitat.


2021 ◽  
Vol 3 (73) ◽  
pp. 06-08
Author(s):  
O. Stakovetskaya ◽  
N. Kulikova

Morphological changes occur in the leaves of trees under the influence of various air pollutants. Recording and assessing these changes reflects the state of the environment. The aim of the study was to assess the level of air pollution in the city of Kineshma, Ivanovo region, using the bioindication method. The technique of morphometry of pedunculate oak leaves and calculation of the index of fluctuating asymmetry were used. In all points of the city, a high asymmetry of oak leaf blades was noted, which indicates a critical level of atmospheric pollution. Ecotoxicants contained in emissions from enterprises and vehicles significantly violate the bilateral symmetry of oak leaf blades.


2021 ◽  
Author(s):  
◽  
Maira Genevieve Oliver

<p>Hermaphroditic reef fish display remarkable diversity in mating strategies, social structure, and the timing of sex change. Understanding spatial variation in reproductive ecology and physiological condition is important in the design of marine reserve systems and fisheries management for species that change sex. I investigated patterns in reproductive ecology, condition, and the influence of the underlying physical environment, for a temperate protogynous (female first) hermaphrodite, the spotty (Notolabrus celidotus) at a small spatial scale. First, I used SCUBA surveys to visually estimate density, sex ratio, and size-frequency to describe the social structure of two populations of spotties located at either end of a 9 km gradient in swell exposure. I then collected individuals from both locations to estimate growth, mortality, and the timing of maturation and sex change for each population. To estimate and compare physiological stress and condition of individuals sampled from these two locations, I used otoliths to quantify fluctuating asymmetry (a measure of stress) and I compared this to other commonly used condition indices. Lastly, I estimated spatial variation in social structure and a set of environmental variables at 30 sites along a gradient of swell exposure to investigate correlations between the physical environment and the density, sex ratio, and size-frequency of spotties. The results revealed that social structure differed markedly between two populations but not always as expected. A low ratio of males to females in sheltered Kau Bay suggested that the rate of sex change was constrained for this population (relative to Wahine Park, a more swell-exposed site, where males were more abundant in the population). Individuals from Kau Bay exhibited slower growth and higher mortality estimates, and in line with predictions of the size advantage model, females appeared to change sex at an early age and smaller size relative to Wahine Park. Contrary to expectations, however, low levels of fluctuating asymmetry suggested the population at Kau Bay was less stressed than Wahine Park, despite evidence for reduced physiological condition (Fulton’s condition factor K) and high density at Kau Bay. Differences in fluctuating asymmetry between sexes and size classes suggested that sex-specific fluctuating asymmetry and stressors later in the life history are important in these populations. Furthermore, correlations between social structure and the physical environment were inconclusive and highlight the necessity for large sampling efforts. Overall, this study concludes that availability of spawning-territory may limit the rate of sex change and influence reproductive potential in this species. This process may be applicable to other protogynous species that rely on territory-defense as a mating strategy. Sex-specific expression of fluctuating asymmetry should be considered in hermaphroditic reef fish and the impact of stressors acting on specific stages in the life history of individuals requires further investigation. Furthermore, my results suggest that condition indices and fluctuating asymmetry cannot be used interchangeably to estimate health for these populations (the metrics may provide complementary information). Overall, these results emphasise complex and variable patterns in the reproductive ecology of hermaphroditic species and my work is among the first to demonstrate such patterns over a small spatial scale. Further work can clarify questions raised in this study and benefit the conservation of hermaphroditic reef fish.</p>


2021 ◽  
Author(s):  
◽  
Maira Genevieve Oliver

<p>Hermaphroditic reef fish display remarkable diversity in mating strategies, social structure, and the timing of sex change. Understanding spatial variation in reproductive ecology and physiological condition is important in the design of marine reserve systems and fisheries management for species that change sex. I investigated patterns in reproductive ecology, condition, and the influence of the underlying physical environment, for a temperate protogynous (female first) hermaphrodite, the spotty (Notolabrus celidotus) at a small spatial scale. First, I used SCUBA surveys to visually estimate density, sex ratio, and size-frequency to describe the social structure of two populations of spotties located at either end of a 9 km gradient in swell exposure. I then collected individuals from both locations to estimate growth, mortality, and the timing of maturation and sex change for each population. To estimate and compare physiological stress and condition of individuals sampled from these two locations, I used otoliths to quantify fluctuating asymmetry (a measure of stress) and I compared this to other commonly used condition indices. Lastly, I estimated spatial variation in social structure and a set of environmental variables at 30 sites along a gradient of swell exposure to investigate correlations between the physical environment and the density, sex ratio, and size-frequency of spotties. The results revealed that social structure differed markedly between two populations but not always as expected. A low ratio of males to females in sheltered Kau Bay suggested that the rate of sex change was constrained for this population (relative to Wahine Park, a more swell-exposed site, where males were more abundant in the population). Individuals from Kau Bay exhibited slower growth and higher mortality estimates, and in line with predictions of the size advantage model, females appeared to change sex at an early age and smaller size relative to Wahine Park. Contrary to expectations, however, low levels of fluctuating asymmetry suggested the population at Kau Bay was less stressed than Wahine Park, despite evidence for reduced physiological condition (Fulton’s condition factor K) and high density at Kau Bay. Differences in fluctuating asymmetry between sexes and size classes suggested that sex-specific fluctuating asymmetry and stressors later in the life history are important in these populations. Furthermore, correlations between social structure and the physical environment were inconclusive and highlight the necessity for large sampling efforts. Overall, this study concludes that availability of spawning-territory may limit the rate of sex change and influence reproductive potential in this species. This process may be applicable to other protogynous species that rely on territory-defense as a mating strategy. Sex-specific expression of fluctuating asymmetry should be considered in hermaphroditic reef fish and the impact of stressors acting on specific stages in the life history of individuals requires further investigation. Furthermore, my results suggest that condition indices and fluctuating asymmetry cannot be used interchangeably to estimate health for these populations (the metrics may provide complementary information). Overall, these results emphasise complex and variable patterns in the reproductive ecology of hermaphroditic species and my work is among the first to demonstrate such patterns over a small spatial scale. Further work can clarify questions raised in this study and benefit the conservation of hermaphroditic reef fish.</p>


Author(s):  
Ashly N. Romero ◽  
D. Rex Mitchell ◽  
Siobhán B. Cooke ◽  
Claire A. Kirchhoff ◽  
Claire E. Terhune

Trees ◽  
2021 ◽  
Author(s):  
Silvia Ecaterina García-Jain ◽  
Yurixhi Maldonado-López ◽  
Ken Oyama ◽  
Marcílio Fagundes ◽  
Maurício Lopes de Faria ◽  
...  

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