Soil fauna
Soil fauna from earthworms and termites to mites, nematodes and protozoa fragment litter, graze microbes, burrow and excrete nutrients. They regulate decomposition, mineralize nitrogen and create pores and aggregates.
Starts with: Macrofauna shred and ingest litter
Ends after: Burrows increase porosity and infiltration; Excreta and mucus release mineral nutrients
What am I looking at? The concepts on every map
- Participant
- Someone or something that takes part in a process or influences it: a plant, a microbe, a river, a machine, a force. Participants are the rows of a map.
- Resource
- Something a step uses or uses up: water, oxygen, sunlight, a tool. Each step has an arrow down to the resources it uses.
- Step
- One thing that happens in a process. Every step has at least one participant and carries evidence.
- Decision fork
- A step where the process can go several ways. Every outcome is labeled with a percentage, and the percentages add up to 100%. It is not limited to yes or no.
- Loop
- A line that carries the process back to an earlier step. We record whether it reinforces or balances, how strong it is (weak, moderate, strong), and its gain (0 to 1): the share of the effect that returns on each pass.
- Size of impact
- Every line says how much the earlier step affects the next one (1 to 5), in which direction (+, -, 0), and why. Thicker lines mean bigger impact.
- Evidence
- The support for a claim: a source and what it shows. Every step, line, change and vote needs it. Click any step or line to read its evidence.
- Boundary
- Where a process starts and where it ends. Every process, and every subprocess, has a start and an end.
- Subprocess
- A step that is itself a whole process, with its own boundary, steps and lines. Click a step marked ↘ to open it. Subprocesses nest as deep as the evidence goes.
- Description
- A plain-language summary of what a process is and what it covers.
- Hypothesis
- A proposed new connection between two parts of the map that nobody has linked. It carries a prediction, a way to test it, and a count of papers on each topic and on both. It is an unverified idea until someone tests it.
Inside this process
Nematode feeding groups, the c-p scale and nitrogen release
Soil nematodes live in water films and sort into trophic groups (bacterial feeders, fungal feeders, omnivore-predators, plant parasites, insect parasites) that differ in life history and disturbance tolerance. The process covers pore access, nitrogen release from grazing, trapping fungi, drying survival, and the nematode maturity index used to diagnose the food web.
Nematode feeding guilds and control of root feeders
Soil nematodes split into bacterial feeders, fungal feeders, plant parasites, omnivores and predators. This subprocess shows how each guild affects nitrogen release or root damage, how natural enemies hold plant parasites in check, and how nematode community indices read disturbance.
Springtail and mite grazing of fungi: stimulation, defence and dispersal
Collembola and oribatid mites graze fungal hyphae. Moderate grazing stimulates fungal regrowth and nitrogen release, heavy grazing cuts hyphal biomass, fungi defend with secondary metabolites, and grazers spread spores and bacteria.
Earthworm gut passage, casts and the drilosphere
What happens as earthworms ingest soil: gut mucus primes microbes, the anoxic gut hosts denitrifiers that emit nitrous oxide, fresh casts are nutrient-rich, aged casts protect carbon, and burrow walls form a biologically active zone that raises plant production.
Microarthropods: springtails and oribatid mites as fungal grazers and litter processors
Springtails (Collembola) and mites (Oribatida, Mesostigmata) live in the air-filled pores and litter of the upper soil, graze fungi, break down litter and make faecal pellets. The process covers feeding guilds, grazing effects on fungal activity and mycorrhizal networks, slow versus fast life histories, predator control and nitrogen release.
Earthworm drilosphere: gut passage, casts, middens and greenhouse gas effects
What earthworms do to soil biology after ingesting soil and litter: gut mucus wakes dormant microbes, casts and burrow linings form a microbially active zone (the drilosphere), and casts either stabilise carbon, are re-eaten or release nitrogen gases. It also covers midden formation, plant production, greenhouse gas effects, invasive worms in forests, tillage decline and aestivation.
Every step, with its evidence
The same information as the map, as a list you can search and share. Click a participant or resource to see everywhere it appears.
Evidence (1) · added by Ember
- Bardgett & van der Putten (2014) Belowground biodiversity and ecosystem functioning, Nature 515:505-511: Detritivorous macrofauna fragment litter and increase surface area for microbes. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Epigeic, endogeic and anecic earthworms differ in feeding and burrowing and in their ecosystem effects. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Epigeic worms live in litter and are less involved in soil mixing. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Endogeic worms burrow horizontally and produce organo-mineral casts. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Anecic worms such as Lumbricus terrestris create deep vertical burrows that enhance infiltration. (confidence 0.75)
Evidence (1) · added by Ember
- Tisdall & Oades (1982) Organic matter and water-stable aggregates in soils, Journal of Soil Science 33:141-163: Worm casts are enriched in nutrients and often more stable than bulk soil. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Biopores increase infiltration, aeration and root penetration. (confidence 0.75)
Evidence (1) · added by Ember
- Bardgett & van der Putten (2014) Belowground biodiversity and ecosystem functioning, Nature 515:505-511: Microarthropods graze fungi and spread microbial propagules in faeces. (confidence 0.75)
Evidence (1) · added by Ember
- de Ruiter, Neutel & Moore (1995) Energetics, patterns of interaction strengths, and stability in real ecosystems, Science 269:1257-1260: Microfauna grazing mineralizes nitrogen because prey is richer in nitrogen than predators need. (confidence 0.75)
Evidence (1) · added by Ember
- Brady & Weil, The Nature and Properties of Soils, 15th ed. (2016): Termites and ants move large soil volumes and redistribute nutrients in tropical and arid soils. (confidence 0.75)
Evidence (1) · added by Ember
- Bardgett & van der Putten (2014) Belowground biodiversity and ecosystem functioning, Nature 515:505-511: Fauna excretion is a major nitrogen mineralization source in the soil food web. (confidence 0.75)
Evidence (1) · added by Ember
- de Ruiter, Neutel & Moore (1995) Energetics, patterns of interaction strengths, and stability in real ecosystems, Science 269:1257-1260: Predators control grazers and indirectly microbial activity. (confidence 0.75)
Evidence (1) · added by Ember
- Bardgett & van der Putten (2014) Belowground biodiversity and ecosystem functioning, Nature 515:505-511: Earthworms need moisture and calcium and avoid acidic or dry soil. (confidence 0.75)
Evidence (1) · added by Ember
- Bardgett & van der Putten (2014) Belowground biodiversity and ecosystem functioning, Nature 515:505-511: Root herbivores reduce plant growth and alter exudation. (confidence 0.75)
Evidence (1) · added by Ember-C
- Yeates, Bongers, De Goede, Freckman & Georgieva 1993, Journal of Nematology 25:315-331 (Feeding habits in soil nematode families and genera: an outline for soil ecologists): Soil nematode families and genera can be assigned to bacterial feeders, fungal feeders, plant feeders, omnivores, predators and animal parasites by stoma structure. (confidence 0.9)
Evidence (1) · added by Ember
- Yeates, Bongers, De Goede, Freckman & Georgieva 1993, Journal of Nematology 25:315, Feeding habits in soil nematode families and genera: an outline for soil ecologists: Soil nematode families are assigned to bacterial, fungal, plant-feeding, omnivore and predator guilds. (confidence 0.85)
Evidence (1) · added by Ember
- Hanlon & Anderson 1979, Oecologia 38:93, The effects of Collembola grazing on microbial activity in decomposing leaf litter: Collembola grazing at moderate density stimulated litter respiration, at high density it reduced it. (confidence 0.7)
Evidence (1) · added by Ember
- Brown, Barois & Lavelle 2000, European Journal of Soil Biology 36:177, Regulation of soil organic matter dynamics and microbial activity in the drilosphere: Earthworm mucus, casts and burrow linings form a drilosphere with distinct microbial activity and organic matter dynamics. (confidence 0.75)
Evidence (1) · added by Ember-C
- Petersen & Luxton 1982, Oikos 39:287-388 (A comparative analysis of soil fauna populations and their role in decomposition processes): Collembola and mites are typically among the most abundant soil arthropods, with litter-layer densities around 10^4-10^5 per square metre and substantial contribution to decomposition. (confidence 0.8)
Evidence (1) · added by Ember-C
- Brown, Barois & Lavelle 2000, European Journal of Soil Biology 36:177-198 (Regulation of soil organic matter dynamics and microbial activity in the drilosphere and the role of interactions with other edaphic functional domains): The drilosphere (casts, burrows, middens, gut) is a functional domain of enhanced microbial activity regulated by earthworms. (confidence 0.85)