scholarly journals For flux’s sake: General considerations for energy-flux calculations in ecological communities

2021 ◽  
Author(s):  
Malte Jochum ◽  
Andrew Barnes ◽  
Ulrich Brose ◽  
Benoit Gauzens ◽  
Marie Sünnemann ◽  
...  
Keyword(s):  
Global Change ◽  
Food Web ◽  
Energy Flux ◽  
Ecosystem Functioning ◽  
Theoretical Background ◽  
Ecological Communities ◽  
Ecological Research ◽  
Trophic Networks ◽  
Community Data ◽  
Food Web Theory

Global change alters ecological communities with consequences for ecosystem processes. Such processes and functions are a central aspect of ecological research and vital to understanding and mitigating the consequences of global change, but also those of other drivers of change in organism communities. In this context, the concept of energy flux through trophic networks integrates food-web theory and biodiversity-ecosystem functioning theory and connects biodiversity to multitrophic ecosystem functioning. As such, the energy flux approach is a strikingly effective tool to answer central questions in ecology and global-change research. This might seem straight forward, given that the theoretical background and software to efficiently calculate energy flux are readily available. However, the implementation of such calculations is not always straight forward, especially for those who are new to the topic and not familiar with concepts central to this line of research, such as food-web theory or metabolic theory. To facilitate wider use of energy flux in ecological research, we thus provide a guide to adopting energy-flux calculations for people new to the method, struggling with its implementation, or simply looking for background reading, important resources, and standard solutions to the problems everyone faces when starting to quantify energy fluxes for their community data. First, we introduce energy flux and its use in community and ecosystem ecology. Then, we provide a comprehensive explanation of the single steps towards calculating energy flux for community data. Finally, we discuss remaining challenges and exciting research frontiers for future energy-flux research.

scholarly journals Marine archaea and archaeal viruses under global change

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1241 ◽  
Author(s):  
Roberto Danovaro ◽  
Eugenio Rastelli ◽  
Cinzia Corinaldesi ◽  
Michael Tangherlini ◽  
Antonio Dell'Anno
Keyword(s):  
Global Change ◽  
Food Web ◽  
Ecosystem Functioning ◽  
Biogeochemical Cycles ◽  
Structure And Function ◽  
Food Web Structure ◽  
Web Structure ◽  
Archaeal Viruses ◽  
And Function ◽  
Marine Archaea

Global change is altering oceanic temperature, salinity, pH, and oxygen concentration, directly and indirectly influencing marine microbial food web structure and function. As microbes represent >90% of the ocean’s biomass and are major drivers of biogeochemical cycles, understanding their responses to such changes is fundamental for predicting the consequences of global change on ecosystem functioning. Recent findings indicate that marine archaea and archaeal viruses are active and relevant components of marine microbial assemblages, far more abundant and diverse than was previously thought. Further research is urgently needed to better understand the impacts of global change on virus–archaea dynamics and how archaea and their viruses can interactively influence the ocean’s feedbacks on global change.

scholarly journals Food web structure alters ecological communities top-heaviness with little effect on the biodiversity-functioning relationship

2020 ◽  
Author(s):  
Eva Delmas ◽  
Daniel B. Stouffer ◽  
Timothée Poisot
Keyword(s):  
Food Web ◽  
Food Chain ◽  
Ecosystem Functioning ◽  
Ecosystem Processes ◽  
Ecosystem Dynamics ◽  
Ecosystem Functions ◽  
Ecological Communities ◽  
Bioenergetic Model ◽  
Food Web Structure ◽  
Web Structure

In a rapidly changing world, the composition, diversity and structure of ecological communities face many threats. Biodiversity-Ecosystem Functioning (BEF) and community food-chain analyses have focused on investigating the consequences of these changes on ecosystem processes and the resulting functions. These different and diverging conceptual frameworks have each produced important results and identified a set of important mechanisms, that shape ecosystem functions. But the disconnection between these frameworks, and the various simplifications of the study systems are not representative of the complexity of real-world communities. Here we use food webs as a more realistic depiction of communities, and use a bioenergetic model to simulate their biomass dynamics and quantify the resulting flows and stocks of biomass. We use tools from food web analysis to investigate how the predictions from BEF and food-chain analyses fit together, how they correlate to food-web structure and how it might help us understand the interplay between various drivers of ecosystem functioning. We show that food web structure is correlated to the community’s efficiency in storing the captured biomass, which may explain the distribution of biomass (top heaviness) across the different trophic compartments (producers, primary and secondary consumers). While we know that ecological network structure is important in shaping ecosystem dynamics, identifying structural attributes important in shaping ecosystem processes and synthesizing how it affects various underpinning mechanisms may help prioritize key conservation targets to protect not only biodiversity but also its structure and the resulting services.

scholarly journals Microplastics and phagotrophic soil protists: evidence of ingestion

2021 ◽  
Author(s):  
E P Kanold ◽  
M C Rillig ◽  
PM Antunes
Keyword(s):  
Global Change ◽  
Fluorescence Microscopy ◽  
Food Web ◽  
Ecosystem Functioning ◽  
Marine Environments ◽  
Soil Food Web ◽  
Fluorescent Microspheres ◽  
Food Vacuoles ◽  
Soil Protists ◽  
Over Time

Microplastics (MPs) can now be found in all the Earth’s biomes, thereby representing a global change phenomenon with largely unknown consequences for biodiversity and ecosystem functioning. Soil protists are eukaryotic, primarily single celled organisms that play important roles in the soil food web. Microplastics have been shown to affect protist populations in freshwater and marine environments, yet the interactions between soil protists and MPs remains largely unknown. Here we examined whether phagotrophic soil protists can ingest MPs and experience declines in abundance. We exposed protists to soil treatments with different concentrations of MPs using commercial polymer fluorescent microspheres and used fluorescence microscopy to find evidence of MP ingestion. In addition, we quantified the total number of active phagotrophic protists over time. We show that most soil protists (>75% individuals) can readily ingest and keep MP within their food vacuoles, even at relatively small MP concentrations (0.1% w/w). There was a trend for higher prevalence of ingestion and for declines in protist abundance at the highest concentration of MPs (1% w/w). However, more data are necessary to further ascertain cause-effect relationships. This is the first report indicating that soil protists can play an important role in the transport and uptake of MPs in the soil food web.

scholarly journals The more food webs change, the more they stay the same

2009 ◽  
Vol 364 (1524) ◽  
pp. 1789-1801 ◽  
Author(s):  
Kevin Shear McCann ◽  
Neil Rooney
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Scale Invariant ◽  
Food Web Structure ◽  
Behavioural Responses ◽  
Web Structure ◽  
Food Web Ecology ◽  
Food Web Theory

Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in space and time. Empirical evidence suggests that underlying attributes of food webs are potentially scale-invariant such that food webs are characterized by hump-shaped trophic structures with fast and slow pathways that repeat at different resolutions within the food web. We place these empirical patterns within the context of recent food-web theory to show that adaptable food-web structure confers stability to an assemblage of interacting organisms in a variable world. Finally, we show that recent food-web analyses agree with two of the major predictions of this theory. We argue that the next major frontier in food-web theory and applied food-web ecology must consider the influence of variability on food-web structure.

scholarly journals Analysis of complex trophic networks reveals the signature of land-use intensification on soil communities in agroecosystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juliette M. G. Bloor ◽  
Sara Si-Moussi ◽  
Pierre Taberlet ◽  
Pascal Carrère ◽  
Mickaël Hedde
Keyword(s):  
Land Use ◽  
Food Web ◽  
Agricultural Intensification ◽  
Environmental Dna ◽  
Trophic Group ◽  
Interaction Networks ◽  
Land Use Intensity ◽  
Food Web Structure ◽  
Trophic Networks ◽  
Management Intensity

AbstractIncreasing evidence suggests that agricultural intensification is a threat to many groups of soil biota, but how the impacts of land-use intensity on soil organisms translate into changes in comprehensive soil interaction networks remains unclear. Here for the first time, we use environmental DNA to examine total soil multi-trophic diversity and food web structure for temperate agroecosystems along a gradient of land-use intensity. We tested for response patterns in key properties of the soil food webs in sixteen fields ranging from arable crops to grazed permanent grasslands as part of a long-term management experiment. We found that agricultural intensification drives reductions in trophic group diversity, although taxa richness remained unchanged. Intensification generally reduced the complexity and connectance of soil interaction networks and induced consistent changes in energy pathways, but the magnitude of management-induced changes depended on the variable considered. Average path length (an indicator of food web redundancy and resilience) did not respond to our management intensity gradient. Moreover, turnover of network structure showed little response to increasing management intensity. Our data demonstrates the importance of considering different facets of trophic networks for a clearer understanding of agriculture-biodiversity relationships, with implications for nature-based solutions and sustainable agriculture.

scholarly journals Genetic diversity increases food-web persistence in the face of climate warming

2020 ◽  
Author(s):  
Matthew A. Barbour ◽  
Daniel J. Kliebenstein ◽  
Jordi Bascompte
Keyword(s):  
Genetic Diversity ◽  
Food Web ◽  
Allelic Variation ◽  
Chemical Defenses ◽  
Trophic Levels ◽  
Raw Material ◽  
Ecological Communities ◽  
Warming Scenario ◽  
The Face ◽  
Loss Of Genetic Diversity

Genetic diversity provides the raw material for species to adapt and persist in the face of climate change. Yet, the extent to which these genetic effects scale at the level of ecological communities remains unclear. Here we experimentally test the effect of plant genetic diversity on the persistence of an insect food web under a current and future warming scenario. We found that plant genetic diversity increased food-web persistence by increasing the intrinsic growth rates of species across multiple trophic levels. This positive effect was robust to a 3°C warming scenario and resulted from allelic variation at two genes that control the biosynthesis of chemical defenses. Our results suggest that the ongoing loss of genetic diversity may undermine the persistence and functioning of ecosystems in a changing world.One Sentence SummaryThe loss of genetic diversity accelerates the extinction of inter-connected species from an experimental food web.

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