scholarly journals Food Chains and Food Webs in Aquatic Ecosystems

2020 ◽  
Vol 10 (14) ◽  
pp. 5012
Author(s):  
Ihn-Sil Kwak ◽  
Young-Seuk Park
Keyword(s):  
Food Webs ◽  
Species Interactions ◽  
Aquatic Ecosystems ◽  
Empirical Studies ◽  
Experimental Studies ◽  
Environmental Dna ◽  
Gut Contents ◽  
Food Chains ◽  
Energy Flows ◽  
Structure Of Communities

Food chains and food webs describe the structure of communities and their energy flows, and they present interactions between species. Recently, diverse methods have been developed for both experimental studies and theoretical/computational studies on food webs as well as species interactions. They are effectively used for various applications, including the monitoring and assessment of ecosystems. This Special Issue includes six empirical studies on food chains and food webs as well as effects of environmental factors on organisms in aquatic ecosystems. They confirmed the usefulness of their methods including isotope, DNA-barcoding with gut contents, and environmental DNA for biological monitoring and ecosystem assessment.

scholarly journals Studying insect diversity in the tropics

1999 ◽  
Vol 354 (1391) ◽  
pp. 1811-1824 ◽  
Author(s):  
H. C. J. Godfray ◽  
O. T. Lewis ◽  
J. Memmott
Keyword(s):  
Food Webs ◽  
Trophic Structure ◽  
Community Dynamics ◽  
Experimental Studies ◽  
Leaf Miner ◽  
Insect Diversity ◽  
Insect Community ◽  
Structure Of Communities ◽  
Modern Ecology ◽  
The Tropics

Understanding the extent and causes of insect diversity in the humid tropics is one of the major challenges in modern ecology. We review some of the current approaches to this problem, and discuss how future progress may be made. Recent calculations that there may be more than 30 million species of insect on earth have focused attention on the magnitude of this problem and stimulated several new lines of research (although the true figure is now widely thought to be between five and ten million species). We discuss work based on insecticidal fogging surveys; studies of herbivore and parasitoid specificity; macroecological approaches; and the construction of food webs. It is argued that progress in estimating insect diversity and in understanding insect community dynamics will be enhanced by building local inventories of species diversity, and in descriptive and experimental studies of the trophic structure of communities. As an illustration of work aimed at the last goal, we discuss the construction and analysis of quantitative host–parasitoid food webs, drawing on our work on leaf miner communities in Central America.

Persistence in food webs—I Lotka-Volterra food chains

1979 ◽  
Vol 41 (6) ◽  
pp. 877-891 ◽  
Author(s):  
T GARD ◽  
T HALLAM
Keyword(s):  
Food Webs ◽  
Food Chains

scholarly journals Estimation accuracy of species abundance based on environmental DNA with relation to its production source, state, and assay methodology suggested by meta-analyses

2021 ◽  
Author(s):  
Toshiaki Jo ◽  
Hiroki Yamanaka
Keyword(s):  
Meta Analysis ◽  
Empirical Studies ◽  
Species Abundance ◽  
Environmental Dna ◽  
Efficient Estimation ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Abundance Estimation ◽  
Natural Environments ◽  
Promising Tool

Environmental DNA (eDNA) analysis is a promising tool for non-disruptive and cost-efficient estimation of species abundance. However, its practical applicability in natural environments is limited because it is unclear whether eDNA concentrations actually represent species abundance in the field. Although the importance of accounting for eDNA dynamics, such as transport and degradation, has been discussed, the influences of eDNA characteristics, including production source and state, and methodology, including collection and quantification strategy and abundance metrics, on the accuracy of eDNA-based abundance estimation were entirely overlooked. We conducted a meta-analysis using 56 previous eDNA literature and investigated the relationships between the accuracy (R2) of eDNA-based abundance estimation and eDNA characteristics and methodology. Our meta-regression analysis found that R2 values were significantly lower for crustaceans than fish, suggesting that less frequent eDNA production owing to their external morphology and physiology may impede accurate estimation of their abundance via eDNA. Moreover, R2 values were positively associated with filter pore size, indicating that selective collection of larger-sized eDNA, which is typically fresher, could improve the estimation accuracy of species abundance. Furthermore, R2 values were significantly lower for natural than laboratory conditions, while there was no difference in the estimation accuracy among natural environments. Our findings shed a new light on the importance of what characteristics of eDNA should be targeted for more accurate estimation of species abundance. Further empirical studies are required to validate our findings and fully elucidate the relationship between eDNA characteristics and eDNA-based abundance estimation.

Removal of Polycyclic Aromatic Hydrocarbons from Sediments using Chemical Oxidation Processes

2015 ◽  
Vol 18 (1) ◽  
Author(s):  
Chiu-Wen Chen ◽  
Nguyen Thanh Binh ◽  
Chang-Mao Hung ◽  
Chih-Feng Chen ◽  
Cheng-Di Dong
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Potassium Permanganate ◽  
Aromatic Hydrocarbons ◽  
Aquatic Ecosystems ◽  
Chemical Oxidation ◽  
Food Chains ◽  
Ecological Risks ◽  
Treatment Efficiency ◽  
Oxidation Processes ◽  
Polycyclic Aromatic

AbstractThe presence of polycyclic aromatic hydrocarbons (PAHs) in sediments is a major concern of risks associated with the aquatic ecosystems through bioaccumulation in food chains. To minimize the ecological risks due to contaminated sediments, processes that can degrade the sorbed PAHs are urgently needed. The present study aims at assessing the treatment efficiency of several chemical oxidation processes using potassium permanganate (KMnO

A European Evaluation of the Promises of LOs

2011 ◽  
pp. 515-531
Author(s):  
Robert McCormick ◽  
Tomi Jaakkola ◽  
Sami Nurmi
Keyword(s):  
Empirical Studies ◽  
Experimental Studies ◽  
Routine Data ◽  
Learning Objects ◽  
Digital Learning ◽  
Online Surveys ◽  
Semistructured Interviews ◽  
E Learning ◽  
Funded Project ◽  
The Impact

Most studies on reusable digital learning materials, Learning Objects (LOs), relate to their use in universities. Few empirical studies exist to explore the impact of LOs on pedagogy, especially in schools. This chapter provides evidence from an evaluation of the use of LOs in schools. The evidence is from an EU-funded project Context E-Learning with Broadband Technologies, involving 500 schools in six countries across Europe, to examine the impact of LOs on pedagogy. It brought together producers and users to try out technically and pedagogically sound ways of producing, making available through a portal, and using LOs. This chapter reports data from both quantitative and qualitative studies conducted during 2004, including: online surveys (of all the teachers involved), routine data from the portal, semistructured interviews in 40 schools in all six countries, experimental studies in one of these countries, and 13 classroom case studies in four of the countries.

Predator–prey interactions and climate change

2019 ◽  
pp. 199-220 ◽  
Author(s):  
Vincent Bretagnolle ◽  
Julien Terraube
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Experimental Studies ◽  
Trophic Levels ◽  
Generalist Predators ◽  
Top Down ◽  
Predator Prey ◽  
Key Topics ◽  
Available Information

Climate change is likely to impact all trophic levels, although the response of communities and ecosystems to it has only recently received considerable attention. Further, it is expected to affect the magnitude of species interactions themselves. In this chapter, we summarize why and how climate change could affect predator–prey interactions, then review the literature about its impact on predator–prey relationships in birds, and provide prospects for future studies. Expected effects on prey or predators may include changes in the following: distribution, phenology, population density, behaviour, morphology, or physiology. We review the currently available information concerning particular key topics: top-down versus bottom-up control, specialist versus generalist predators, functional versus numerical responses, trophic cascades and regime shifts, and lastly adaptation and selection. Finally, we focus our review on two well-studied bird examples: seabirds and raptors. Key future topics include long-term studies, modelling and experimental studies, evolutionary questions, and conservation issues.

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