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This springtail (Collembola) is one of the tiny creatures in soil that, along with other animals like spiders and earthworms, contributes to nutrient cycling and decomposition. Researchers analysed soil from 19 countries to explore how the variety of feeding activities of such animals changed according to climate and agriculture.
Photo Credit: Frank Ashwood
Scientific Frontline: Extended "At a Glance" Summary: Soil Animal Trophic Diversity
The Core Concept: Soil animal communities display a greater variety of feeding activities, known as trophic diversity, within agricultural ecosystems and tropical regions compared to woodlands and temperate zones.
Key Distinction/Mechanism: Rather than simplifying food webs, resource limitation in agricultural systems and high competition in tropical soils force soil animals to broaden their diets and undergo stronger niche differentiation. Animals that feed on microorganisms occupy more varied trophic positions than predators or detritivores.
Major Frameworks/Components:
- Trophic Diversity: The variety of feeding activities and specific positions organisms occupy within interconnected ecological food chains.
- Stable Isotope Analysis: The measurement of carbon and nitrogen ratios to accurately trace the energy flow, diets, and trophic levels of 28 major groups of soil organisms.
- Niche Differentiation: The ecological process by which competing species utilize the environment differently to coexist, observed strongly in tropical soil communities.
- Dietary Plasticity: The flexibility of generalist soil animals to expand their feeding habits to buffer ecosystem processes during environmental disturbance or resource scarcity.
Branch of Science: Soil Ecology, Agroecology, Zoology, Biogeochemistry
Future Application: Developing highly precise predictive models to assess the stability, decomposition rates, and nutrient cycling capacities of soil systems under expanding agricultural land use and global climate change.
Why It Matters: The findings challenge the conventional expectation that intensive land use uniformly simplifies ecological communities, demonstrating that understanding species' feeding roles is as critical as measuring raw species richness for assessing ecosystem resilience.
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| Nematodes have adapted to a range of ecosystems across the land and sea. Most, like this one, live in the soil feeding on living material. They are one of the groups of animals that were part of the study about effects of different environments on the diversity of feeding activities. Photo Credit: Haifeng Yin |
Soils are home to some of the most diverse animal communities on Earth. These animals—including nematodes, springtails, mites, earthworms, spiders, and other arthropods—drive decomposition, regulate microbial communities, and contribute to nutrient cycling. However, little is known about how these animals’ “trophic diversity”—meaning the variety of feeding activities—is affected by land use and climate. An international research team led by the University of Göttingen has now shown that soil animal communities have greater trophic diversity in agricultural ecosystems and in tropical regions. The study analyzed carbon and nitrogen stable isotope ratios from over 17,000 soil samples, covering 28 major groups of organisms from 456 sites across 19 countries. The results were published in Nature Ecology & Evolution.
The researchers found that animals that feed on microorganisms—such as nematodes, springtails, and mites—had higher trophic diversity than those that feed on dead organic matter or live as predators. This suggests that microbial feeders exploit a particularly broad range of resources and occupy more varied trophic positions—meaning where they are on the interconnected food chains in an ecosystem. One of the most surprising findings was that soil animal trophic diversity was about 32% higher in agricultural systems than in woodlands. This contrasts with the common expectation that intensive land use generally simplifies ecological communities. The researchers suggest that agricultural environments, where resources are often more limited and patchily distributed, may force soil animals to broaden their diets or divide resources more strongly among groups of organisms.
“This does not mean that agriculture is beneficial for soil biodiversity,” says Dr. Zheng Zhou, first author of the study, who is now at Hohenheim University. “Rather, our results suggest that soil animals in agricultural systems may respond to resource limitation and disturbance by expanding how they feed. This feeding flexibility likely helps to maintain soil functions, but it may also reflect the loss of specialized species.”
The study also found that trophic diversity was about 40% higher in tropical than in temperate regions. Tropical soils are typically characterized by fast decomposition, low accumulation of organic matter, and strong competition for resources. Under these conditions, soil animals may partition resources more finely or expand the range of resources they use. The higher diversity of feeding activities in the tropics was therefore linked not only to higher species richness but also to stronger niche differentiation among soil animal groups.
“Our findings show that soil animal communities adjust their specific position in a food chain or web with changes in land use,” says Stefan Scheu, professor of animal ecology at the University of Göttingen and a senior author of the study. “This flexibility may help to buffer ecosystem processes such as decomposition and nutrient cycling in the face of global change. However, it also raises the question of whether soil animals that are flexible generalists in the long term can replace the role of specialists in disturbed ecosystems.”
The study highlights that soil biodiversity cannot be understood by counting species alone. The feeding roles of soil animals, and how these roles change across land-use systems and climate regions, are crucial for predicting the stability and functioning of soil systems under global change.
Published in journal: Nature Ecology & Evolution
Authors: Zheng Zhou, Nico Eisenhauer, Andrew D. Barnes, Melanie M. Pollierer, Malte Jochum, Ingo Grass, Yan Zhang, Ulrich Brose, Fujio Hyodo, Nicole Scheunemann, Olaf Schmidt, Yuanyuan Huang, Bernhard Klarner, Anton A. Goncharov, Alena Krause, Daniil Korobushkin, Anastasia Gorbunova, Ilya I. Lyubechanskii, Sergey M. Tsurikov, Julia Seeber, Michael Steinwandter, Vladimir A. Zryanin, Oksana L. Rozanova, Winda Ika Susanti, Felicity V. Crotty, Di Ajeng Prameswari, Zhipeng Li, Carol Melody, Zhijing Xie, Xue Pan, Donghui Wu, Mark Maraun, Katerina Sam, Alexei V. Tiunov, Stefan Scheu, and Anton Potapov
Source/Credit: Georg-August-Universität Göttingen
Reference Number: eco051226_01