Overcoming the Challenges of Studying Soil Nematodes: A New Approach with Implications for All (Soil) Organisms

Post provided by Stefan Geisen

(Soil) Nematodes

“…if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes…” (Cobb 1914)

He may have said it more than a century ago but we now, more than ever, realise that Nathan Augustus Cobb was right. Nematodes are by far the most abundant animals soil, freshwater and marine ecosystems. These tiny worms are barely visible to the human eye (if they’re visible at all), hundreds can inhabit a single gram of soil . Their similar shape might lead you to think that they’re all alike, but that’s not the case. More than 25,000 species have been identified and estimates put their entire species diversity in the 100,000s.

Some common nematode species found in most soils. a) Plectus sp; b) Aphelenchus sp; c) Helicotylenchus sp; d) Thonus sp; e) Mononchus sp; © Wageningen University, Laboratory of Nematology, NL; Hanny van Megen

Some common nematode species found in most soils. a) Plectus sp, b) Aphelenchus sp, c) Helicotylenchus sp, d) Thonus sp, e) Mononchus sp. © Wageningen University, Laboratory of Nematology, NL; Hanny van Megen

This taxonomic and functional diversity has boosted nematodes to become useful bioindicators for soil quality. Nematodes perform many different functions in both terrestrial and aquatic ecosystems. These are mainly defined by what they eat:

  • Bacteria/Fungi: Many nematode groups eat bacteria and fungi. They control the population of these organisms and keep them active.
  • Plants: Plant feeders are the unwanted guests in agricultural systems as well as in our gardens. They can destroy entire harvests by piercing into or infiltrating roots.
  • Omnivores/Predators: Many nematode species prey on other smaller organisms including smaller nematodes and control their abundances.
  • Parasites: These species inhabit other larger organisms and can act as biocontrol agents.

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Issue 9.2

Issue 9.2 is now online!

The February issue of Methods is now online!

This double-size issue contains six Applications articles (one of which is Open Access) and two Open Access research articles. These eight papers are freely available to everyone, no subscription required.

 Temperature Manipulation: Welshofer et al. present a modified International Tundra Experiment (ITEX) chamber design for year-round outdoor use in warming taller-stature plant communities up to 1.5 m tall.This design is a valuable tool for examining the effects of in situ warming on understudied taller-stature plant communities

 ZoonThe disjointed nature of the current species distribution modelling (SDM) research environment hinders evaluation of new methods, synthesis of current knowledge and the dissemination of new methods to SDM users. The zoon R package aims to overcome these problems by providing a modular framework for constructing reproducible SDM workflows.

 BEIN R Package: The Botanical Information and Ecology Network (BIEN) database comprises an unprecedented wealth of cleaned and standardised botanical data. The bien r package allows users to access the multiple types of data in the BIEN database. This represents a significant achievement in biological data integration, cleaning and standardisation.

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Methods in Ecology and Evolution 2017: The Year in Review

Happy New Year! We hope that you all had a wonderful Winter Break and that you’re ready to start 2018. We’re beginning the year with a look back at some of our highlights of 2017. Here’s how last year looked at Methods in Ecology and Evolution.

The Articles

We published some amazing articles in 2017, too many to mention them all here. However, we would like to take a moment to thank all of the Authors, Reviewers and Editors who contributed to the journal last year. Your time and effort make the journal what it is and we are incredibly grateful. THANK YOU for all of your hard work!

Technological Advances at the Interface between Ecology and Statistics

Our first Special Feature of the year came in the April issue of the journal. The idea for Technological Advances at the Interface between Ecology and Statistics  came from the 2015 Eco-Stats Symposium at the University of New South Wales and the feature was guest edited by Associate Editor David Warton. It consists of five articles based on talks from that conference and shows how interdisciplinary collaboration help to solve problems around estimating biodiversity and how it changes over space and time.

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Microbial Methods Virtual Issue

The BES Microbial Ecology Special Interest Group is running a workshop today (Thursday 2 November) on Novel Tools for Microbial Ecology. To compliment this workshop, Xavier Harrison has edited a Virtual Issue of the best Methods in Ecology and Evolution articles on advances in methods of studying microbial evolution and ecology from the past few years.

Advances in Next-Generation Sequencing (NGS) technology now allow us to study associations between hosts and their microbial communities in unprecedented detail. However, studies investigating host-microbe interactions in the field of ecology and evolution are dominated by 16S and ITS amplicon sequencing. While amplicon sequencing is a useful tool for describing microbial community composition, it is limited in its ability to quantify the function(s) performed by members of those communities. Characterising function is vital to understanding how microbes and their hosts interact, and consequently whether those interactions are adaptive for, or detrimental to, the host. The articles in this Virtual Issue cover a broad suite of approaches that allow us to study host-microbe and microbe-microbe interactions in novel ways.

All of the articles in the Microbial Methods Virtual Issue will be freely available for the next two months. You can find out a little more about each one below. Continue reading

Exploring Microbial Diversity: From the Sequence to the Cell

Post provided by Ruben Props, Michelle Berry, Marian Schmidt, Frederiek-Maarten Kerckhof, Vincent Denef and Nico Boon

Searching Lake Michigan (USA) for uncharacterized microbial diversity. © Michelle Berry

Searching Lake Michigan (USA) for uncharacterized microbial diversity. © Michelle Berry

Exploring microbial diversity and relating it to ecosystem functions is one of the primary occupations of microbiologists and microbial ecologists worldwide. Unfortunately, recent studies have shown that the microbial census is far from complete and that it is heavily biased towards certain (host-associated) environments. With the Earth’s microbial diversity estimated at an impressive one trillion (1012) taxa, the search continues for new technologies and methodologies that may help us better describe, monitor and preserve the microbial diversity of our planet’s natural and engineered ecosystems.

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Issue 6.5

Issue 6.5 is now online!

The May issue of Methods is now online!

We have two freely available articles this month: one Application and one Open Access Article.

rSPACE: An open-source R package for implementing a spatially based power analysis for designing monitoring programs. This method incorporates information on species biology and habitat to parameterize a spatially explicit population simulation.

Tim Lucas et al. provide this month’s Open Access article: A generalised random encounter model for estimating animal density with remote sensor data. The authors have developed a Generalised Random Encounter Model (gREM) to estimate absolute animal density from count data from both camera traps and acoustic detectors. They show that gREM produces accurate estimates of absolute animal density for all combinations of sensor detection widths and animal signal widths. This model is applicable for count data obtained in both marine and terrestrial environments, visually or acoustically. It could be used for big cats, sharks, birds, echolocating bats, cetaceans and much more. Continue reading