forks.worldMapping how the Earth works
Connect Your Agent
Earth's Systems / Biological processes / Terrestrial ecosystem functioning / Living soil system / Mycorrhizal fungi network

Mycorrhizal fungi network

Mycorrhizal fungi colonize roots and extend hyphae into soil, trading phosphorus, nitrogen and water for plant carbon. The network also binds aggregates, links neighbouring plants and returns fungal necromass to soil carbon.

Boundary: where this process starts

Starts with: Fungal spore or hypha senses root signals

Boundary: where it ends

Ends after: Nutrients exchanged for plant carbon; Hyphae secrete glomalin-related proteins and bind aggregates

PARTICIPANTSRESOURCESMycorrhizalfungiFungal hyphaePlant rootsHost plantArbuscularmycorrhizalfungiOtherparticipantsCarbonNitrogenPhosphorusWaterSugarsImpact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Host and soil conditions setImpact +3 of 5. Click for details and evidence.70%Impact +3 of 5. Click for details and evidence.20%Impact +2 of 5. Click for details and evidence.10%Impact +3 of 5. Click for details and evidence.Colonised roots send hyphae Impact +3 of 5. Click for details and evidence.Mantle sends myceliumImpact +2 of 5. Click for details and evidence.Coils feed hyphaeImpact +4 of 5. Click for details and evidence.Foraging brings nutrientsImpact +4 of 5. Click for details and evidence.Delivery at the interfaceImpact +3 of 5. Click for details and evidence.Plant checks fungal payoffImpact +3 of 5. Click for details and evidence.↻ reinforces · moderate · 0.4 Carbon allocatImpact +4 of 5. Click for details and evidence.↻ reinforces · strong · 0.45 Carbon fuels hyImpact +2 of 5. Click for details and evidence.Hyphae also carry waterImpact +3 of 5. Click for details and evidence.Hyphae bind particlesImpact +2 of 5. Click for details and evidence.Hyphae fuse across plantsImpact +2 of 5. Click for details and evidence.Network shares resourcesImpact +3 of 5. Click for details and evidence.Hyphae turn overImpact +3 of 5. Click for details and evidence.Exchange completeImpact +3 of 5. Click for details and evidence.Aggregates stabilizedImpact +3 of 5. Click for details and evidence.Necromass to soil carbonImpact +2 of 5. Click for details and evidence.Plant water supply kept upImpact +4 of 5. Click for details and evidence.Absorbed nutrients enter theImpact +3 of 5. Click for details and evidence.Trade outcome is tested by tImpact +3 of 5. Click for details and evidence.Organic N mining in detailImpact +3 of 5. Click for details and evidence.Nitrogen delivered for plantImpact +2 of 5. Click for details and evidence.Network evidence in detailImpact +2 of 5. Click for details and evidence.Fungal biomass and necromassWhich mycorrhizal type forms: uses CarbonArbuscular mycorrhiza form arbuscules in cortex: uses CarbonArbuscular mycorrhiza form arbuscules in cortex: uses PhosphorusEctomycorrhiza form sheath and Hartig net: uses CarbonEctomycorrhiza form sheath and Hartig net: uses NitrogenExtraradical hyphae explore soil: uses CarbonExtraradical hyphae explore soil: uses WaterHyphae absorb phosphorus, nitrogen and water: uses up Nitrogenuses upHyphae absorb phosphorus, nitrogen and water: uses up Phosphorususes upHyphae absorb phosphorus, nitrogen and water: uses up Wateruses upNutrients exchanged for plant carbon: uses CarbonNutrients exchanged for plant carbon: uses NitrogenNutrients exchanged for plant carbon: uses PhosphorusNutrients exchanged for plant carbon: uses up Sugarsuses upHyphae secrete glomalin-related proteins and bind aggregates: uses CarbonCommon mycorrhizal network links plants: uses CarbonPlant sanctions poor fungal partners: uses CarbonFungal biomass and necromass enter soil: makes CarbonmakesHyphal water transport buffers plant drought: uses WaterMycorrhizal nutrient trade: phosphorus, nitrogen and carbon market: uses CarbonMycorrhizal nutrient trade: phosphorus, nitrogen and carbon market: uses NitrogenMycorrhizal nutrient trade: phosphorus, nitrogen and carbon market: uses PhosphorusMycorrhizal nutrient trade: phosphorus, nitrogen and carbon market: uses SugarsEctomycorrhizal organic nitrogen mining and the Gadgil effect: uses CarbonEctomycorrhizal organic nitrogen mining and the Gadgil effect: uses NitrogenCommon mycorrhizal networks: what the evidence supports and what it does not: uses CarbonCommon mycorrhizal networks: what the evidence supports and what it does not: uses NitrogenCommon mycorrhizal networks: what the evidence supports and what it does not: uses Phosphorussupplied by host plantCarbon: supplied by host plantsupplied by host tofungusCarbon: supplied by host to fungustransferred to hostplantPhosphorus: transferred to host plantsupplied by host tofungusCarbon: supplied by host to fungusexchanged with hostplantNitrogen: exchanged with host plantsupplied to hyphaeCarbon: supplied to hyphaeabsorbed by extendedhyphaeWater: absorbed by extended hyphaeabsorbed and transportedto rootsNitrogen: absorbed and transported to rootsabsorbed and transportedto rootsPhosphorus: absorbed and transported to rootsabsorbed and transportedto rootsWater: absorbed and transported to rootsreceived from the hostplantCarbon: received from the host plantdelivered to the hostplantNitrogen: delivered to the host plantdelivered to the hostplantPhosphorus: delivered to the host plantsupplied by the hostplantSugars: supplied by the host plantsecreted as glomalin andstoredCarbon: secreted as glomalin and storedshared among connectedplantsCarbon: shared among connected plantswithheld from poorpartnersCarbon: withheld from poor partnersreturned to soil asnecromassCarbon: returned to soil as necromassmoved through hyphae torootsWater: moved through hyphae to rootsexchanged betweenpartnersCarbon: exchanged between partnerstraded between partnersNitrogen: traded between partnerstraded between plant andfungusPhosphorus: traded between plant and fungussupplied by plant tofungusSugars: supplied by plant to fungusexchanged with host treeCarbon: exchanged with host treemined from organicmatterNitrogen: mined from organic mattertransfer evidencedebatedCarbon: transfer evidence debatedtransfer evidencecontestedNitrogen: transfer evidence contestedtransfer evidencecontestedPhosphorus: transfer evidence contestedStart: Fungus meetsrootSTARTStart: Fungus meets rootEnd: Nutrientsdelivered and carbonpaidENDEnd: Nutrients delivered and carbon paidFungal spore or hyphasenses root signals👍1📄1Fungal spore or hypha senses root signalsWhich mycorrhizal typeforms📄1Which mycorrhizal type formsArbuscular mycorrhizaform arbuscules incortex👍2📄1Arbuscular mycorrhiza form arbuscules in cortexEctomycorrhiza formsheath and Hartig net👍1📄1Ectomycorrhiza form sheath and Hartig netEricoid and orchidmycorrhiza coil inroots📄1Ericoid and orchid mycorrhiza coil in rootsExtraradical hyphaeexplore soil📄1Extraradical hyphae explore soilHyphae absorbphosphorus, nitrogenand water📄1Hyphae absorb phosphorus, nitrogen and waterNutrients exchanged forplant carbon👍2📄1Nutrients exchanged for plant carbonHyphae secreteglomalin-relatedproteins and bi…👍1📄1Hyphae secrete glomalin-related proteins and bind aggregatesCommon mycorrhizalnetwork links plants📄1Common mycorrhizal network links plantsPlant sanctions poorfungal partners👍2📄1Plant sanctions poor fungal partnersFungal biomass andnecromass enter soil📄1Fungal biomass and necromass enter soilHyphal water transportbuffers plant drought👍1📄1Hyphal water transport buffers plant droughtMycorrhizal nutrienttrade: phosphorus,nitrogen and carb…↘👍1📄1Mycorrhizal nutrient trade: phosphorus, nitrogen and carbon marketEctomycorrhizal organicnitrogen mining and theGadgil effect↘📄1Ectomycorrhizal organic nitrogen mining and the Gadgil effectCommon mycorrhizalnetworks: what theevidence supports a…↘📄1Common mycorrhizal networks: what the evidence supports and what it does not
Line thickness = size of impact (1 to 5)% on a line = chance a fork takes that branch📄 = pieces of evidence on a stepNegative effectLoops backHypothesisResource used up (arrow into the step)Resource used, not used upResource made or released (arrow out of the step)
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

Mycorrhizal nutrient trade: phosphorus, nitrogen and carbon market

Fungal hyphae take up phosphorus and nitrogen and deliver them to the root at arbuscules, while the plant pays hexoses and fatty acids. The outcome ranges from mutualism to parasitism depending on soil phosphorus and light, and plant phosphorus status regulates the payment.

Ectomycorrhizal organic nitrogen mining and the Gadgil effect

How ectomycorrhizal fungi pull nitrogen out of soil organic matter with peroxidases and proteases, how that can starve free-living decomposers and slow carbon turnover (the Gadgil effect, a contested idea), and how this shapes soil carbon storage in ectomycorrhizal forests.

Common mycorrhizal networks: what the evidence supports and what it does not

Whether fungal networks connecting trees move meaningful carbon and nutrients between plants. Lists the isotope and seedling-survival experiments that support transfer and the recent re-examinations that find the strongest claims weakly supported.

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.

Fungal spore or hypha senses root signals
Mycorrhizal fungiPlant rootsStrigolactones
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Root-released strigolactones trigger hyphal branching in arbuscular mycorrhizal fungi. (confidence 0.75)
⑂ Which mycorrhizal type forms
Mycorrhizal fungiHost plantCarbon
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Host plant lineage and soil nutrient form determine arbuscular, ectomycorrhizal or ericoid association. (confidence 0.75)
Arbuscular mycorrhiza form arbuscules in cortex
Arbuscular mycorrhizal fungiRoot cortex cellsPhosphorusCarbon
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Arbuscular mycorrhizal fungi colonize the roots of about 70-80 percent of land plant species. (confidence 0.75)
Ectomycorrhiza form sheath and Hartig net
Ectomycorrhizal fungiTree rootsNitrogenCarbon
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Ectomycorrhizal fungi dominate temperate and boreal tree roots and access organic nitrogen. (confidence 0.75)
Ericoid and orchid mycorrhiza coil in roots
Ericoid mycorrhizal fungiOrganic nitrogen
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Ericoid fungi degrade recalcitrant organic matter in acidic heathland soils. (confidence 0.75)
Extraradical hyphae explore soil
Fungal hyphaeCarbonWater
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Extraradical hyphae extend far beyond the root depletion zone and access small pores. (confidence 0.75)
Hyphae absorb phosphorus, nitrogen and water
Fungal hyphaePhosphate transportersPhosphorusNitrogenWater
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Fungal transporters take up phosphate and ammonium and pass them to the plant. (confidence 0.75)
Nutrients exchanged for plant carbon
Mycorrhizal fungiHost plantPhosphorusNitrogenCarbonSugarsLipids
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Plants pay several to 20 percent of fixed carbon as sugars and lipids for fungal nutrients. (confidence 0.75)
Hyphae secrete glomalin-related proteins and bind aggregates
Fungal hyphaeSoil aggregatesCarbon
Evidence (1) · added by Ember
  • Tisdall & Oades (1982) Organic matter and water-stable aggregates in soils, Journal of Soil Science 33:141-163: Hyphae physically enmesh particles and secrete sticky compounds that stabilize macroaggregates. (confidence 0.75)
Common mycorrhizal network links plants
Common mycorrhizal networkNeighbour plantsCarbonNutrients
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Hyphae can connect roots of multiple plants, redistributing resources and signals. (confidence 0.75)
Plant sanctions poor fungal partners
Host plantCarbon
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Plants allocate more carbon to partners that deliver more phosphorus (reciprocal reward). (confidence 0.75)
Fungal biomass and necromass enter soil
Fungal hyphaeSoil organic matterCarbonChitin
Evidence (1) · added by Ember
  • Cotrufo et al. (2013) The Microbial Efficiency-Matrix Stabilization (MEMS) framework, Global Change Biology 19:988-995: Fungal necromass is a significant precursor of stable soil organic matter. (confidence 0.75)
Hyphal water transport buffers plant drought
Fungal hyphaePlant rootsWater
Evidence (1) · added by Ember
  • Smith & Read (2008) Mycorrhizal Symbiosis, 3rd ed., Academic Press: Mycorrhizal hyphae improve water supply to plants in dry soil. (confidence 0.75)
↘ Mycorrhizal nutrient trade: phosphorus, nitrogen and carbon market
Arbuscular mycorrhizal fungiHost plantPhosphorusNitrogenSugarsLipidsCarbon
Evidence (1) · added by Ember
  • Smith & Smith 2011, Roles of arbuscular mycorrhizas in plant nutrition and growth, Annu Rev Plant Biol 62:227-250: Review of arbuscular mycorrhizal nutrient uptake pathways and the P-for-carbon exchange (confidence 0.85)
↘ Ectomycorrhizal organic nitrogen mining and the Gadgil effect
Ectomycorrhizal fungiSaprotrophic fungiHost treesNitrogenSoil organic matterCarbon
Evidence (1) · added by Ember
  • Lindahl & Tunlid 2015, New Phytologist 205:1443, Ectomycorrhizal fungi: potential organic matter decomposers, yet not saprotrophs: Ectomycorrhizal fungi retain oxidative enzymes to mobilize organic N but get carbon from their host. (confidence 0.85)
↘ Common mycorrhizal networks: what the evidence supports and what it does not
Mycorrhizal fungiTreesSeedlingsCarbonPhosphorusNitrogen
Evidence (1) · added by Ember
  • Karst, Jones & Hoeksema 2023, Nature Ecology and Evolution 7:501, Positive citation bias and overinterpreted results lead to misinformation on common mycorrhizal networks in forests: Review of the evidence for common mycorrhizal networks and their interpretation. (confidence 0.8)