scholarly journals Effect of Artificial Regime Shifts and Biotic Factors on the Intensity of Foraging of Planktivorous Fish

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Krzysztof Ciszewski ◽  
Wawrzyniec Wawrzyniak ◽  
Przemysław Czerniejewski
Keyword(s):  
Abiotic Factors ◽  
Experimental System ◽  
Aquatic Organisms ◽  
Planktivorous Fish ◽  
Large Prey ◽  
Biotic Factors ◽  
Water Column Stratification ◽  
Physiological Processes ◽  
Oxygen Conditions ◽  
Elevated Water

It is still to be confirmed whether global warming with its predicted elevated water temperature will cause an increase in predation and alter phenological and physiological processes leading to changes in the size of aquatic organisms. In an experimental system of water column stratification simulating a natural combination of field conditions, we created artificial abiotic factors that mimicked the natural environment, i.e., light intensity, oxygen conditions, and thermal stratification. Subsequently, we added biotic factors such as algae, Daphnia, and planktivorous fish. We studied the intensity of foraging of planktivorous fish on individuals of Daphnia per min in different conditions of biotic and abiotic gradients. We demonstrated a possible scenario involving the risk of elimination of large prey within macrocladocera communities by predatory pressure as a result of climate change. A higher intensity of foraging of planktivorous fish caused or increased the occurrence of larger groups of planktonic animals with a smaller body size. The mechanisms of a future scenario were discovered at a higher trophic level in the aquatic environment.

scholarly journals Mycobacterium ulcerans dynamics in aquatic ecosystems are driven by a complex interplay of abiotic and biotic factors

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Andrés Garchitorena ◽  
Jean-François Guégan ◽  
Lucas Léger ◽  
Sara Eyangoh ◽  
Laurent Marsollier ◽  
...  
Keyword(s):  
Climatic Factors ◽  
Abiotic Factors ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Mycobacterium Ulcerans ◽  
Environmental Data ◽  
Limiting Factor ◽  
Biotic Factors ◽  
Abiotic And Biotic Factors ◽  
Chemical Conditions

Host–parasite interactions are often embedded within complex host communities and can be influenced by a variety of environmental factors, such as seasonal variations in climate or abiotic conditions in water and soil, which confounds our understanding of the main drivers of many multi-host pathogens. Here, we take advantage of a combination of large environmental data sets on Mycobacterium ulcerans (MU), an environmentally persistent microorganism associated to freshwater ecosystems and present in a large variety of aquatic hosts, to characterize abiotic and biotic factors driving the dynamics of this pathogen in two regions of Cameroon. We find that MU dynamics are largely driven by seasonal climatic factors and certain physico-chemical conditions in stagnant and slow-flowing ecosystems, with an important role of pH as limiting factor. Furthermore, water conditions can modify the effect of abundance and diversity of aquatic organisms on MU dynamics, which suggests a different contribution of two MU transmission routes for aquatic hosts (trophic vs environmental transmission) depending on local abiotic factors.

Determination of factors involved in the rejection of bananas (Musa acuminata) intended for international commercialization

2020 ◽  
Keyword(s):  
Management Practices ◽  
Abiotic Factors ◽  
Quality Standards ◽  
Musa Acuminata ◽  
P Value ◽  
Biotic Factors ◽  
Significance Level ◽  
Export Sector ◽  
Export System

The banana agro-export sector in Ecuador provides millions of dollars in income for this concept, but with this development, a series of quality standards have been established that must be met to enter the export system. This has contributed to establishing good post-harvest production and management practices that guarantee the optimal production of bananas and plantains. The objective of this study was to determine the factors involved in the rejection of bananas (Musa acuminata) destined for international commercialization. The methodology considered the design modality of non-experimental transactional research, with a quantitative approach. The methodological design was developed in three phases at Finca 6 Hermanas located in the Barraganete sector of the San Juan parish in the Puebloviejo canton of the Los Ríos Province, Ecuador. The results highlight that the main causes for which banana rejection is generated are due to abiotic factors (damage, dry latex, scar, insect damage, broken neck, overgrowth) in a higher percentage of 79.55 % and biotic factors ( twins, diseases, short finger) by 20.45 %. The average rejection was 6 361 fingers and1 269 Kilograms (K) over the 6-week study duration. The analysis of variance turned out to be significant for variable 1 (biotic and abiotic). Ho is rejected; with the criterion of p-value < 0.0001 and F (9; 45) = 2.10., F = 13.17> F critic. In the case of variable (2) “work weeks”, Ho is accepted with the criteria obtained of p-value of 0.7694 and F (5; 45) = 2.4., As F = 0.51 < F critic, it is concludes, that with a significance level of 5% the null hypothesis is accepted. It is concluded that these figures lead to the elaboration of strategies that systemically mitigate the damages, by correcting each one of the causes that cause the deterioration of the banana and increasing the economic gains of the commercialization process.

scholarly journals Delayed Senescence in Soybean: Terminology, Research Update, and Survey Results from Growers

2016 ◽  
Vol 17 (2) ◽  
pp. 76-83 ◽  
Author(s):  
C. J. Harbach ◽  
T. W. Allen ◽  
C. R. Bowen ◽  
J. A. Davis ◽  
C. B. Hill ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Biotic Factors ◽  
Delayed Senescence ◽  
Plant Parts ◽  
Whole Plant ◽  
Research Findings ◽  
Survey Results ◽  
Soybean Plants ◽  
Grower Survey ◽  
Specific Symptoms

The terms used to describe symptoms of delayed senescence in soybean often are used inconsistently or interchangeably and do not adequately distinguish the observed symptoms in the field. Various causes have been proposed to explain the development of delayed senescence symptoms. In this article, we review published reports on delayed senescence symptoms in soybean, summarize current research findings, provide examples of terms related to specific symptoms, and present an overview of the results of a multi-state survey directed to soybean growers to understand their concerns about delayed soybean senescence. Some of these terms, such as green bean syndrome and green stem syndrome, describe symptoms induced by biotic factors, while other terms describe symptoms associated with abiotic factors. Some delayed senescence terms involve the whole plant remaining green while other terms include just the stem and other plant parts such as pods. In the grower survey, 77% reported observing soybean plants or plant parts that remained green after most plants in the field were fully mature with ripe seed. Most respondents attributed these symptoms to changes in breeding and choice of cultivars. At the end of this article, we standardized the terms used to describe delayed senescence in soybean. Accepted for publication 23 March 2016. Published 15 April 2016.

scholarly journals Biogeomorphic feedbacks and the ecosystem engineering of recently deglaciated terrain

2018 ◽  
Vol 43 (1) ◽  
pp. 24-45 ◽  
Author(s):  
Hannah R Miller ◽  
Stuart N Lane
Keyword(s):  
Environmental Stress ◽  
Ecosystem Engineer ◽  
Abiotic Factors ◽  
Ecosystem Engineering ◽  
Soil Development ◽  
Water Dynamics ◽  
Biotic Factors ◽  
Successional Stage ◽  
Abiotic And Biotic Factors

Matthews’ 1992 geoecological model of vegetation succession within glacial forefields describes how following deglaciation the landscape evolves over time as the result of both biotic and abiotic factors, with the importance of each depending on the level of environmental stress within the system. We focus in this paper on how new understandings of abiotic factors and the potential for biogeomorphic feedbacks between abiotic and biotic factors makes further development of this model important. Disturbance and water dynamics are two abiotic factors that have been shown to create stress gradients that can drive early ecosystem succession. The subsequent establishment of microbial communities and vegetation can then result in biogeomorphic feedbacks via ecosystem engineering that influence the role of disturbance and water dynamics within the system. Microbes can act as ecosystem engineers by supplying nutrients (via remineralization of organic matter and nitrogen fixation), enhancing soil development, either decreasing (encouraging weathering) or increasing (binding sediment grains) geomorphic stability, and helping retain soil moisture. Vegetation can act as an ecosystem engineer by fixing nitrogen, enhancing soil development, modifying microbial community structure, creating seed banks, and increasing geomorphic stability. The feedbacks between vegetation and water dynamics in glacial forefields are still poorly studied. We propose a synthesized model of ecosystem succession within glacial forefields that combines Matthews’ initial geoecological model and Corenblit's model to illustrate how gradients in environmental stress combined with successional time drive the balance between abiotic and biotic factors and ultimately determine the successional stage and potential for biogeomorphic feedbacks.

Reproductive phenology of sympatric taxa of Chamaecrista (Leguminosae) in Serra do Cipó, Brazil

1999 ◽  
Vol 15 (4) ◽  
pp. 463-479 ◽  
Author(s):  
João A. Madeira ◽  
G. Wilson Fernandes
Keyword(s):  
Seed Predation ◽  
Rainy Season ◽  
Plant Architecture ◽  
Abiotic Factors ◽  
Reproductive Phenology ◽  
Biotic Factors ◽  
Selective Force ◽  
Monthly Average ◽  
Serra Do Cipó ◽  
Mature Seeds

Reproductive phenology of 13 sympatric taxa of Chamaecrista in three sections was surveyed at Serra do Cipó, south-east Brazil. Mean abundance of flowers and fruits per plant and mean number of aborted, predated, and surviving seeds per fruit were estimated. Monthly average number of developed seeds per fruit multiplied by the monthly mean number of fruits per plant gave the monthly average number of seeds produced by a plant of each taxon. Five types of phenological behaviour were differentiated by cluster analyses according to the season during which each species produced most of its mature seeds. This behaviour was related to the taxonomic section to which the taxa belong, to plant architecture, to geographical range, to seed predation and to local climatic seasonality. Herbs were more affected by variation in rainfall than shrubs and trees. Two species did not show any clear seasonal behaviour. Widespread taxa produced most of their mature seeds in the rainy season or immediately after it, and all but one of the narrowly distributed species produced most of their mature seeds in the dry season or in the transition from dry to rainy season. Seed predation is probably not an important selective force affecting reproductive phenology of larger taxa, while the smaller taxa seemed too constrained by abiotic factors for biotic factors to influence their phenology significantly.

scholarly journals Relative effects of biotic and abiotic factors during early life history on recruitment dynamics: a case study

2017 ◽  
Vol 74 (7) ◽  
pp. 1125-1134 ◽  
Author(s):  
Fan Zhang ◽  
Kevin B. Reid ◽  
Thomas D. Nudds
Keyword(s):  
Life History ◽  
Yellow Perch ◽  
Lake Erie ◽  
Abiotic Factors ◽  
Zooplankton Abundance ◽  
Biotic Factors ◽  
Large Lakes ◽  
Middle Term ◽  
Biotic And Abiotic Factors ◽  
Juvenile Stages

The relative effects of biotic and abiotic factors, and the life-history stages upon which they act to affect fish recruitment, vary among species and ecosystems. We compared the effects of spawning stock biomass, and factors operating at early-term (encompassing the egg, yolk-sac larval, and first few days of swim-up larval stages), middle-term (including the swim-up larval and pelagic juvenile stages), and late-term (over the benthic juvenile stage) on recruitment by yellow perch (Perca flavescens) in the western basin of Lake Erie between 1999 and 2013. Variation of recruitment was mainly driven by middle-term effects. Then, abiotic factors, such as warming rate and wind speed, more strongly affected recruitment than did biotic factors. Among middle-term biotic factors, the top-down effect of yearling walleye (Sander vitreus) abundance was stronger than the bottom-up effect of zooplankton abundance. Similar to marine species, physical processes appear to strongly affect recruitment dynamics of Lake Erie yellow perch over its pelagic larval and juvenile stages, demonstrating the importance of physical and biological processes in understanding fish population dynamics in large lakes.

scholarly journals Biological enhancement of mineral weathering by <i>Pinus</i> <i>sylvestris</i> seedlings – effects of plants, ectomycorrhizal fungi, and elevated CO<sub>2</sub>

2019 ◽  
Vol 16 (18) ◽  
pp. 3637-3649 ◽  
Author(s):  
Nicholas P. Rosenstock ◽  
Patrick A. W. van Hees ◽  
Petra M. A. Fransson ◽  
Roger D. Finlay ◽  
Anna Rosling
Keyword(s):  
Nutrient Uptake ◽  
Elevated Co2 ◽  
Ectomycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Abiotic Factors ◽  
Experimental System ◽  
Mineral Weathering ◽  
Low Molecular Weight ◽  
Primary Mechanism ◽  
Seedling Biomass

Abstract. Better understanding and quantifying the relative influence of plants, associated mycorrhizal fungi, and abiotic factors such as elevated CO2 on biotic weathering is essential to constraining weathering estimates. We employed a column microcosm system to examine the effects of elevated CO2 and Pinus sylvestris seedlings, with or without the ectomycorrhizal fungi Piloderma fallax and Suillus variegatus, on rhizosphere soil solution concentrations of low-molecular-weight organic acids (LMWOAs) and on the weathering of primary minerals. Seedlings significantly increased mineral weathering, as estimated from elemental budgets of Ca, K, Mg, and Si. Elevated CO2 increased plant growth and LMWOA concentrations but had no effect on weathering. Colonization by ectomycorrhizal fungi, particularly P. fallax, showed some tendency to increase weathering. LMWOA concentrations correlated with seedling biomass across both CO2 and mycorrhizal treatments but not with total weathering. We conclude that nutrient uptake, which reduces transport limitation to weathering, is the primary mechanism by which plants enhanced weathering in this system. While the experimental system used departs from conditions in forest soils in a number of ways, these results are in line with weathering studies performed at the ecosystem, macrocosm, and microcosm scale, indicating that nutrient uptake by plants and microbes is an important biological mechanism by which mineral weathering is enhanced.

scholarly journals Environmental factors influencing fine-scale distribution of Antarctica’s only endemic insect

Oecologia ◽  
2020 ◽  
Vol 194 (4) ◽  
pp. 529-539
Author(s):  
Leslie J. Potts ◽  
J. D. Gantz ◽  
Yuta Kawarasaki ◽  
Benjamin N. Philip ◽  
David J. Gonthier ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Ecological Factors ◽  
Biotic Interactions ◽  
Species Distributions ◽  
Biotic Factors ◽  
Belgica Antarctica ◽  
Abiotic And Biotic Factors ◽  
The Antarctic

AbstractSpecies distributions are dependent on interactions with abiotic and biotic factors in the environment. Abiotic factors like temperature, moisture, and soil nutrients, along with biotic interactions within and between species, can all have strong influences on spatial distributions of plants and animals. Terrestrial Antarctic habitats are relatively simple and thus good systems to study ecological factors that drive species distributions and abundance. However, these environments are also sensitive to perturbation, and thus understanding the ecological drivers of species distribution is critical for predicting responses to environmental change. The Antarctic midge, Belgica antarctica, is the only endemic insect on the continent and has a patchy distribution along the Antarctic Peninsula. While its life history and physiology are well studied, factors that underlie variation in population density within its range are unknown. Previous work on Antarctic microfauna indicates that distribution over broad scales is primarily regulated by soil moisture, nitrogen content, and the presence of suitable plant life, but whether these patterns are true over smaller spatial scales has not been investigated. Here we sampled midges across five islands on the Antarctic Peninsula and tested a series of hypotheses to determine the relative influences of abiotic and biotic factors on midge abundance. While historical literature suggests that Antarctic organisms are limited by the abiotic environment, our best-supported hypothesis indicated that abundance is predicted by a combination of abiotic and biotic conditions. Our results are consistent with a growing body of literature that biotic interactions are more important in Antarctic ecosystems than historically appreciated.

Impact of urban environment on the occurrence pathological signs in hardwood species

2015 ◽  
Vol 5 (2) ◽  
pp. 71-81
Author(s):  
Перелыгина ◽  
Elena Perelygina ◽  
Разинкова ◽  
Aleksandra Razinkova ◽  
Крюкова ◽  
...  
Keyword(s):  
Urban Environment ◽  
Woody Plants ◽  
Pathological Condition ◽  
Abiotic Factors ◽  
Biotic Factors ◽  
Induced Mutations ◽  
Hardwood Species ◽  
Pathological Appearance ◽  
The Impact ◽  
Negative Factors

The article is devoted to date the impact of negative factors on the urban environment plants. Causes of pathologies can be divided into groups: induced mutations, abiotic factors, human factors, biotic factors. As authors of the research objectives was determined on the basis of an attempt of a pathological condition of the trees reveal the influence of certain groups of factors. Results of the study was to identify the most resistant O-types in the urban environment, a comparison with the pathological appearance-marks on woody plants in the conditions of the urban environment.

scholarly journals An experimental approach to understanding elevation limits in a montane terrestrial salamander, plethodon montanus

2017 ◽  
Author(s):  
Nicholas M. Caruso ◽  
Jeremy F. Jacobs ◽  
Leslie J. Rissler
Keyword(s):  
Evolutionary Biology ◽  
Abiotic Factors ◽  
Transplant Experiment ◽  
Biotic Factors ◽  
Reciprocal Transplant Experiment ◽  
Abiotic Environment ◽  
Environmental Suitability ◽  
Lower Elevation ◽  
Survival And Growth ◽  
Growth And Reproduction

AbstractUnderstanding the abiotic and biotic factors that determine the limits to species’ range is an essential goal in ecology, biogeography, evolutionary biology, and conservation biology. Moreover, predictions of shifts in species’ distributions under future changes in climate can be improved through understanding the spatial variation in survival, growth, and reproduction. A long-standing hypothesis postulates that, for Northern Hemisphere species, abiotic factors like temperature limit northern and/or higher elevation extents, while biotic factors like competition limit the southern and/or lower elevation range edges; though amphibians may not follow this general trend. Therefore, we combined environmental suitability models and a reciprocal transplant experiment across an elevational gradient to explore the role of the abiotic environment on the range limits of a montane salamander (Plethodon montanus). We first determined suitability of the abiotic environment for P. montanus, under current (1960 – 2000) and future (2050) climate scenarios. Second, we collected juveniles from each of three elevations and transplanted them within mesocosms such that each origin population was represented within each transplant location and vice-versa. We found that environmental suitability in 2050 decreased throughout the range compared to current predictions, especially at lower elevations. Additionally, we found that individuals’ starting body condition and transplant location were important predictors of survival, growth, and reproduction condition; importantly, individuals transplanted to low elevation had lower survival and growth rates compared to those moved to mid or high elevations. Our study provides experimental support that the abiotic environment limits the lower elevation distribution of P. montanus and, unfortunately, our results also paint a possible bleak future for this species and likely other montane terrestrial plethodontids. The abiotic environment, which will become increasingly limited under future changes in climate, was found to have more influence on survival and growth than population identity.

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