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 Fire affects root decomposition, soil food web structure, and carbon flow in tallgrass prairie

SOIL ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 199-210 ◽  
Author(s):  
E. Ashley Shaw ◽  
Karolien Denef ◽  
Cecilia Milano de Tomasel ◽  
M. Francesca Cotrufo ◽  
Diana H. Wall
Keyword(s):  
Food Web ◽  
Tallgrass Prairie ◽  
Trophic Levels ◽  
Root Turnover ◽  
Root Decomposition ◽  
Microbial Abundance ◽  
Soil Food Web ◽  
Root Litter ◽  
Flow Through ◽  
Over Time

Abstract. Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is common and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root-litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root-litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable but also significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition, which, in turn, is significantly affected by fire. Not only does fire affect the soil community and root decomposition, but the lower microbial abundance, greater root turnover, and the increased incorporation of root litter C by microbes and nematodes for AB suggests that annual burning increases root-litter-derived C flow through the soil food web of the tallgrass prairie.

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.

The soil food web revisited: Diverse and widespread mycophagous soil protists

2016 ◽  
Vol 94 ◽  
pp. 10-18 ◽  
Author(s):  
Stefan Geisen ◽  
Robert Koller ◽  
Maike Hünninghaus ◽  
Kenneth Dumack ◽  
Tim Urich ◽  
...  
Keyword(s):  
Food Web ◽  
Soil Food Web ◽  
Soil Protists

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 Burning management in the tallgrass prairie affects root decomposition, soil food web structure and carbon flow

2015 ◽  
Vol 2 (2) ◽  
pp. 923-953
Author(s):  
E. A. Shaw ◽  
K. Denef ◽  
C. Milano de Tomasel ◽  
M. F. Cotrufo ◽  
D. H. Wall
Keyword(s):  
Food Web ◽  
Tallgrass Prairie ◽  
Trophic Levels ◽  
Root Decomposition ◽  
Microbial Abundance ◽  
Konza Prairie ◽  
Soil Food Web ◽  
Root Litter ◽  
Flow Through ◽  
Over Time

Abstract. Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is a common management practice and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable, but significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition which, in turn, is significantly affected by fire management practices. Not only does fire affect the soil community and root decomposition for Konza Prairie LTER soils, but the lower microbial abundance, greater root turnover, and the increased incorporation of root litter C by microbes and nematodes for AB suggests that tallgrass prairie management through annual burning increases root litter-derived C flow through the soil food web.

scholarly journals Incorporation of mineral nitrogen into the soil food web as affected by plant community composition

2021 ◽  
Author(s):  
Tanja Strecker ◽  
Annette Jesch ◽  
Dörte Bachmann ◽  
Melissa Jüds ◽  
Kevin Karbstein ◽  
...  
Keyword(s):  
Food Web ◽  
Community Composition ◽  
Plant Community ◽  
Mineral Nitrogen ◽  
Plant Community Composition ◽  
Soil Food Web

Reconstructing the soil food web of a 100 million-year-old forest: The case of the mid-Cretaceous fossils in the amber of Charentes (SW France)

2011 ◽  
Vol 43 (4) ◽  
pp. 726-735 ◽  
Author(s):  
Sina Adl ◽  
Vincent Girard ◽  
Gérard Breton ◽  
Malvina Lak ◽  
Ardhini Maharning ◽  
...  
Keyword(s):  
Food Web ◽  
Soil Food Web ◽  
Cretaceous Fossils ◽  
Sw France
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