scholarly journals The dynamics of food chains under climate change and nutrient enrichment

2012 ◽  
Vol 367 (1605) ◽  
pp. 2935-2944 ◽  
Author(s):  
Amrei Binzer ◽  
Christian Guill ◽  
Ulrich Brose ◽  
Björn C. Rall
Keyword(s):  
Food Chain ◽  
Nutrient Enrichment ◽  
Biodiversity Loss ◽  
Low Fertility ◽  
Interactive Effects ◽  
Large Species ◽  
Negative Effects ◽  
Food Web Structure ◽  
Population Dynamic Model ◽  
The Individual

Warming has profound effects on biological rates such as metabolism, growth, feeding and death of organisms, eventually affecting their ability to survive. Using a nonlinear bioenergetic population-dynamic model that accounts for temperature and body-mass dependencies of biological rates, we analysed the individual and interactive effects of increasing temperature and nutrient enrichment on the dynamics of a three-species food chain. At low temperatures, warming counteracts the destabilizing effects of enrichment by both bottom-up (via the carrying capacity) and top-down (via biological rates) mechanisms. Together with increasing consumer body masses, warming increases the system tolerance to fertilization. Simultaneously, warming increases the risk of starvation for large species in low-fertility systems. This effect can be counteracted by increased fertilization. In combination, therefore, two main drivers of global change and biodiversity loss can have positive and negative effects on food chain stability. Our model incorporates the most recent empirical data and may thus be used as the basis for more complex forecasting models incorporating food-web structure.

Parental breeding age effects on descendants’ longevity interact over two generations in matrilines and patrilines

2019 ◽  
Author(s):  
Zac Wylde ◽  
Foteini Spagopoulou ◽  
Amy K Hooper ◽  
Alexei A Maklakov ◽  
Russell Bonduriansky
Keyword(s):  
Maternal Age ◽  
First Generation ◽  
Age Effects ◽  
Population Variation ◽  
Paternal Age ◽  
Interactive Effects ◽  
Competitive Environment ◽  
Larval Diet ◽  
Negative Effects ◽  
Two Generations

Individuals within populations vary enormously in mortality risk and longevity, but the causes of this variation remain poorly understood. A potentially important and phylogenetically widespread source of such variation is maternal age at breeding, which typically has negative effects on offspring longevity. Here, we show that paternal age can affect offspring longevity as strongly as maternal age does, and that breeding age effects can interact over two generations in both matrilines and patrilines. We manipulated maternal and paternal ages at breeding over two generations in the neriid fly Telostylinus angusticollis. To determine whether breeding age effects can be modulated by the environment, we also manipulated larval diet and male competitive environment in the first generation. We found separate and interactive effects of parental and grandparental ages at breeding on descendants’ mortality rate and lifespan in both matrilines and patrilines. These breeding age effects were not modulated by grandparental larval diet quality or competitive environment. Our findings suggest that variation in maternal and paternal ages at breeding could contribute substantially to intra-population variation in mortality and longevity.

Grünbrücke Loterbuck A 4.2.9: Eine Erfolgskontrolle nach drei Jahren | Fauna Overbridge Loterbuck A 4.2.9: Success Control after a Period of Three Years

2000 ◽  
Vol 151 (8) ◽  
pp. 290-297
Author(s):  
Stephan Hatt
Keyword(s):  
Local People ◽  
Traffic Network ◽  
Negative Effects ◽  
The Individual

The expansion of the traffic network, in particular the construction of highways, has continuously diminished and divided into small sections the habitat of wild-living animals during the last decades. However, these negative effects can be minimised if suitable measures with regard to line-conduction and construction are taken against. One of these possibilities are the sown-down overbridges. It is essential that these constructions are planned and built in order to meet the requirements of their future users – the various wild-living animals. This study investigates the success of one of these sown-down overbridges. It is this the Loterbuck-overbridge on the A 4.2.9 near Henggart in the canton of Zurich, Switzerland. The focus of this investigation was to find out which species of wild-living animals use the bridge and how much it is frequented. Local people and specialists of the region were interviewed and tracks were picked up on site. Taking into consideration five criteria (species of wild-living animals, positioning and number of overbridges nearby, dimensioning and design of the individual overbridges), the interviews and tracks were assessed. The Loterbuck-overbridge is used by all larger wild-living animals of the region. Especially the browsing and rubbing tracks of deer show that the overbridge has been accepted not only as sown-down overbridge but also as habitat.

The Biology of Lakes and Ponds

2017 ◽  
Author(s):  
Christer Brönmark ◽  
Lars-Anders Hansson
Keyword(s):  
Evolutionary Ecology ◽  
Global Climate ◽  
Biodiversity Loss ◽  
Environmental Threats ◽  
Freshwater Organisms ◽  
Abiotic Constraints ◽  
Abiotic And Biotic Factors ◽  
The Individual ◽  
Degraded Ecosystems ◽  
Behavioural Adaptations

The Biology of Lakes and Ponds focuses on the interactions between the abiotic frame, such as turbulence, temperature, pH and nutrients, and the organisms, including interactions with and among organisms at the individual, population and community level. The book fills this niche between traditional limnology and evolutionary ecology by focusing on physiological, morphological and behavioural adaptations among organisms to abiotic and biotic factors and how interactions between biotic processes and abiotic constraints determine the structure and dynamics of lake and pond systems. In addition, the book describes and analyses the causes and consequences of human activities on freshwater organisms and ecosystems and covers longstanding environmental threats, such as eutrophication and acidification, as well as novel threats, such as biodiversity loss, use of everyday chemicals and global climate change. However, also signs of improvement and the possibilities to restore degraded ecosystems are discussed and provide hope for future generations.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

scholarly journals Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1354
Author(s):  
Sergio E. Medina-Cuéllar ◽  
Deli N. Tirado-González ◽  
Marcos Portillo-Vázquez ◽  
Sergio Orozco-Cirilo ◽  
Marco A. López-Santiago ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
Zea Mays L ◽  
N Fertilization ◽  
Human Consumption ◽  
Alluvial Soils ◽  
Grain Production ◽  
Negative Effects ◽  
Maize Stover ◽  
The Individual ◽  
Quadratic Models

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production.

scholarly journals Individual behavioural traits not social context affects learning about novel objects in archerfish

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Nick A. R. Jones ◽  
Helen C. Spence-Jones ◽  
Mike Webster ◽  
Luke Rendell
Keyword(s):  
Social Context ◽  
Social Environment ◽  
Social Contexts ◽  
Negative Effects ◽  
Behavioural Phenotype ◽  
Social Species ◽  
The Social ◽  
Social Animals ◽  
Novel Objects ◽  
The Individual

Abstract Learning can enable rapid behavioural responses to changing conditions but can depend on the social context and behavioural phenotype of the individual. Learning rates have been linked to consistent individual differences in behavioural traits, especially in situations which require engaging with novelty, but the social environment can also play an important role. The presence of others can modulate the effects of individual behavioural traits and afford access to social information that can reduce the need for ‘risky’ asocial learning. Most studies of social effects on learning are focused on more social species; however, such factors can be important even for less-social animals, including non-grouping or facultatively social species which may still derive benefit from social conditions. Using archerfish, Toxotes chatareus, which exhibit high levels of intra-specific competition and do not show a strong preference for grouping, we explored the effect of social contexts on learning. Individually housed fish were assayed in an ‘open-field’ test and then trained to criterion in a task where fish learnt to shoot a novel cue for a food reward—with a conspecific neighbour visible either during training, outside of training or never (full, partial or no visible presence). Time to learn to shoot the novel cue differed across individuals but not across social context. This suggests that social context does not have a strong effect on learning in this non-obligatory social species; instead, it further highlights the importance that inter-individual variation in behavioural traits can have on learning. Significance statement Some individuals learn faster than others. Many factors can affect an animal’s learning rate—for example, its behavioural phenotype may make it more or less likely to engage with novel objects. The social environment can play a big role too—affecting learning directly and modifying the effects of an individual’s traits. Effects of social context on learning mostly come from highly social species, but recent research has focused on less-social animals. Archerfish display high intra-specific competition, and our study suggests that social context has no strong effect on their learning to shoot novel objects for rewards. Our results may have some relevance for social enrichment and welfare of this increasingly studied species, suggesting there are no negative effects of short- to medium-term isolation of this species—at least with regards to behavioural performance and learning tasks.

scholarly journals Interactive effects of climate and nutrient enrichment on patterns of herbivory by different feeding guilds in mangrove forests

2017 ◽  
Vol 26 (11) ◽  
pp. 1326-1338 ◽  
Author(s):  
Ilka C. Feller ◽  
Marilyn C. Ball ◽  
Joanne I. Ellis ◽  
Catherine E. Lovelock ◽  
Ruth Reef
Keyword(s):  
Nutrient Enrichment ◽  
Interactive Effects ◽  
Feeding Guilds ◽  
Mangrove Forests

Psychological Features of Manifestation of Coping-Resources of Schoolteachers

2021 ◽  
Author(s):  
Tetiana Nechytailo ◽  
Halyna Fesun ◽  
Tetiana Kanivets ◽  
Alla Simak
Keyword(s):  
Coping Strategies ◽  
Stress Resistance ◽  
Coping Behavior ◽  
Teaching Profession ◽  
Coping Resources ◽  
Professional Activity ◽  
Personal Resources ◽  
Negative Effects ◽  
Professional Activities ◽  
The Individual

The article is devoted to the psychological peculiarities of the manifestation of coping-resources of educators. The teaching profession belongs to the category of professions especially vulnerable to stress, since the teacher has to solve various professional tasks in the absence of time and information, constant open contact with people, which entails considerable emotional energy. The professional activity of a modern teacher requires constant and maximum mobilization of their personal resources. Maintaining or enhancing a person's stress resistance is associated with finding and using resources well enough to help the educator overcome the negative effects of stressful situations. The article reveals such characteristics of personality and social environment that facilitate or make possible adaptation to life stresses, promotes the development of a means of overcoming it, and increases stress resistance. These personal structures help a person cope with threatening circumstances and facilitate adaptation. The author analyzes the scientific and psychological approaches to understand personal resources, determinants of the choice of coping-strategies, and the influence of the characteristics of professional activity on the behavior of the individual. Questions about structure, functions, and types of coping behavior are raised. According to the majority of modern researchers, the generalized classification of the methods of mastering stressful circumstances is analyzed: coping aimed at evaluation; problem-oriented coping; coping aimed at emotions. Also presented were the most up-to-date and most modern models of coping resources, which can be viewed from different angles to look at the choice of coping-resources by the personality of the teacher, taking into account the conditions of his professional activity. The organization and methods of conducted research of the features of manifestation of coping-resources in teachers are described. The presented quantitative and qualitative results are disclosed according to the stages of the study. In particular, the analysis of teacher’s coping-strategies depending on the level of emotional burnout, ways of overcoming difficult life situations, as well as the methods of coping-behavior of the respondents. Relationships between teachers' coping-resources and emotional and mental stress as well as the monotony of professional activities are also identified. Adaptive and non-adaptive coping behaviors are differentiated in terms of cognitive, emotional, and behavioral coping strategies are analyzed separately. Based on the theoretical analysis of the scientific literature and empirical research, the author substantiates the relevant conclusions and recommendations for school educators on the effective use of their own coping resources.

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