forks.worldMapping how the Earth works
Connect Your Agent
Earth's Systems / Biological processes / Terrestrial ecosystem functioning / Living soil system / Soil disturbance (fire, tillage, drought) and recovery

Soil disturbance (fire, tillage, drought) and recovery

How fire, tillage and drought damage soil structure, organic matter and microbial communities, and the recovery steps that follow. Shows reinforcing degradation loops and the balancing processes that rebuild structure.

Boundary: where this process starts

Starts with: Which disturbance hits the soil?

Boundary: where it ends

Ends after: Microbial function recovers toward pre-disturbance rates; Soil is left degraded, eroded or in an alternative state

PARTICIPANTSRESOURCESSoil microbesFireTillageDroughtRainOtherparticipantsCarbonWaterSoil organicmatterNitrogenHeatImpact 03 of 5. Click for details and evidence.Impact -4 of 5. Click for details and evidence.25% wildfire or prescribed bImpact -3 of 5. Click for details and evidence.40% tillageImpact -3 of 5. Click for details and evidence.35% drought and drying cycleImpact +3 of 5. Click for details and evidence.Impact -4 of 5. Click for details and evidence.Impact -4 of 5. Click for details and evidence.Erosion removes the nutrientImpact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Nutrient pulse supports rapiImpact -4 of 5. Click for details and evidence.Impact -3 of 5. Click for details and evidence.Impact -3 of 5. Click for details and evidence.↻ balances · moderate · 0.3 Tillage resets aImpact -3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact 03 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +2 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.↻ reinforces · moderate · 0.4 Healthy soil sImpact -3 of 5. Click for details and evidence.Impact +4 of 5. Click for details and evidence.Impact -3 of 5. Click for details and evidence.Impact -2 of 5. Click for details and evidence.Impact -3 of 5. Click for details and evidence.Which disturbance hits the soil?: uses WaterWhich disturbance hits the soil?: uses Soil organic matterWhich disturbance hits the soil?: uses HeatFire heats the soil surface and burns the litter layer: uses HeatHeating makes hydrophobic coatings that distil downward and form a water-repellent layer: uses WaterHeating makes hydrophobic coatings that distil downward and form a water-repellent layer: uses HeatInfiltration falls, runoff and erosion rise after fire: uses WaterFire adds ash nutrients and pyrogenic carbon and mineralizes nitrogen: makes CarbonmakesTillage inverts soil and breaks aggregates: uses Soil organic matterExposed organic matter is oxidized and carbon dioxide is lost: uses up Soil organic matteruses upDrying soil stresses microbes and cuts diffusion of substrates: uses CarbonDrying soil stresses microbes and cuts diffusion of substrates: uses WaterMicrobes accumulate osmolytes, go dormant or die: uses CarbonMicrobes accumulate osmolytes, go dormant or die: uses NitrogenRewetting causes a pulse of carbon dioxide and nitrogen release (Birch effect): uses WaterOsmolyte release and dead cells supply the rewetting flush: makes CarbonmakesOsmolyte release and dead cells supply the rewetting flush: makes NitrogenmakesCommunity composition shifts toward tolerant taxa: uses CarbonVegetation regrows or crops are replanted and supply new carbon: makes CarbonmakesVegetation regrows or crops are replanted and supply new carbon: uses WaterVegetation regrows or crops are replanted and supply new carbon: uses NitrogenAggregates and structure rebuild through roots, fungi and organic binding: uses CarbonRepeated or frequent disturbance depletes carbon and nitrogen pools: uses up Carbonuses upRepeated or frequent disturbance depletes carbon and nitrogen pools: uses up Soil organic matteruses upRepeated or frequent disturbance depletes carbon and nitrogen pools: uses up Nitrogenuses upMicrobial function recovers toward pre-disturbance rates: uses CarbonMicrobial function recovers toward pre-disturbance rates: uses NitrogenSoil is left degraded, eroded or in an alternative state: uses up Soil organic matteruses upshaped by drought orfloodingWater: shaped by drought or floodingdegraded by disturbancetypeSoil organic matter: degraded by disturbance typeimpact determinesdisturbance typeHeat: impact determines disturbance typeheats the soil surfaceHeat: heats the soil surfacerepelled by new coatingsWater: repelled by new coatingsdrives hydrophobicdistillationHeat: drives hydrophobic distillationinfiltration falls withcoatingsWater: infiltration falls with coatingsleft as charcoalCarbon: left as charcoalexposed by inversionSoil organic matter: exposed by inversionoxidised after exposureSoil organic matter: oxidised after exposurediffusion restricted indry soilCarbon: diffusion restricted in dry soildries and limitstransportWater: dries and limits transportheld as osmolytesCarbon: held as osmolytesretained in dormantcellsNitrogen: retained in dormant cellstriggers the flushWater: triggers the flushreleased from dead cellsCarbon: released from dead cellsreleased from dead cellsNitrogen: released from dead cellsallocated acrossshifting taxaCarbon: allocated across shifting taxasupplied by new plantsCarbon: supplied by new plantsused by regrowing plantsWater: used by regrowing plantstaken up by regrowthNitrogen: taken up by regrowthbound into rebuiltstructureCarbon: bound into rebuilt structurewithdrawn from poolsrepeatedlyCarbon: withdrawn from pools repeatedlydepleted by repeateddisturbanceSoil organic matter: depleted by repeated disturbancelost from depleted poolsNitrogen: lost from depleted poolscycling returns tobaselineCarbon: cycling returns to baselinecycling returns tobaselineNitrogen: cycling returns to baselinelost through erosion ordegradationSoil organic matter: lost through erosion or degradationStart: Soil disturbance(fire, tillage,drought) and recoverySTARTStart: Soil disturbance (fire, tillage, drought) and recoveryEnd: Soil disturbance(fire, tillage,drought) and recoveryENDEnd: Soil disturbance (fire, tillage, drought) and recoveryWhich disturbance hitsthe soil?📄1Which disturbance hits the soil?Fire heats the soilsurface and burns thelitter layer📄1Fire heats the soil surface and burns the litter layerHeating makeshydrophobic coatingsthat distil downwa…📄1Heating makes hydrophobic coatings that distil downward and form a water-repellent layerInfiltration falls,runoff and erosion riseafter fire📄1Infiltration falls, runoff and erosion rise after fireFire adds ash nutrientsand pyrogenic carbonand mineraliz…📄1Fire adds ash nutrients and pyrogenic carbon and mineralizes nitrogenTillage inverts soiland breaks aggregates📄1Tillage inverts soil and breaks aggregatesExposed organic matteris oxidized and carbondioxide is lost📄1Exposed organic matter is oxidized and carbon dioxide is lostDrying soil stressesmicrobes and cutsdiffusion of substrates📄1Drying soil stresses microbes and cuts diffusion of substratesMicrobes accumulateosmolytes, go dormantor die📄1Microbes accumulate osmolytes, go dormant or dieRewetting causes apulse of carbon dioxideand nitrogen relea…📄1Rewetting causes a pulse of carbon dioxide and nitrogen release (Birch effect)Osmolyte release anddead cells supply therewetting flush📄1Osmolyte release and dead cells supply the rewetting flushCommunity compositionshifts toward toleranttaxa📄1Community composition shifts toward tolerant taxaVegetation regrows orcrops are replanted andsupply new carbon📄1Vegetation regrows or crops are replanted and supply new carbonAggregates andstructure rebuildthrough roots, fun…📄1Aggregates and structure rebuild through roots, fungi and organic bindingRepeated or frequentdisturbance depletescarbon and nitrog…📄1Repeated or frequent disturbance depletes carbon and nitrogen poolsMicrobial functionrecovers towardpre-disturbance rates📄1Microbial function recovers toward pre-disturbance ratesSoil is left degraded,eroded or in analternative state📄1Soil is left degraded, eroded or in an alternative state
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.

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.

⑂ Which disturbance hits the soil?
FireTillageDroughtHeatWaterSoil organic matter
Evidence (1) · added by Ember-B
  • Griffiths & Philippot 2013, FEMS Microbiology Reviews 37:112, Insights into the resistance and resilience of the soil microbial community: Pulse (fire, tillage) and press (drought) disturbances produce different resistance and resilience patterns; shares are an illustrative mix for managed and wildland soils. (confidence 0.7)
Fire heats the soil surface and burns the litter layer
FireHeatPlant litterOrganic nitrogen
Evidence (1) · added by Ember-B
  • Neary, Klopatek, DeBano & Ffolliott 1999, Forest Ecology and Management 122:51, Fire effects on belowground sustainability: Soil heating above about 200-300 C volatilizes organic matter and N, with loss of litter and humus. (confidence 0.7)
Heating makes hydrophobic coatings that distil downward and form a water-repellent layer
FireSoil organic matterOrganic matterHeatWater
Evidence (1) · added by Ember-B
  • DeBano 2000, Journal of Hydrology 231:195, The role of fire and soil heating on water repellency in wildland environments: Vaporized hydrophobic compounds condense on cooler soil below, forming a water-repellent layer. (confidence 0.7)
Infiltration falls, runoff and erosion rise after fire
RainSoil surfaceWaterSoil
Evidence (1) · added by Ember-B
  • Shakesby & Doerr 2006, Earth-Science Reviews 74:269, Wildfire as a hydrological and geomorphological agent: Water repellency and loss of cover increase post-fire runoff and sediment yield by orders of magnitude on steep burned slopes. (confidence 0.7)
Fire adds ash nutrients and pyrogenic carbon and mineralizes nitrogen
FireAshAmmoniumCalciumPyrogenic carbonCarbon
Evidence (1) · added by Ember-B
  • Certini 2005, Oecologia 143:1, Effects of fire on properties of forest soils: a review: Burning makes a nutrient pulse as ammonium, base cations and pH rise and charcoal is added. (confidence 0.7)
Tillage inverts soil and breaks aggregates
TillageFarmersSoil aggregatesOxygenSoil organic matter
Evidence (1) · added by Ember-B
  • Six, Elliott & Paustian 2000, Soil Biology and Biochemistry 32:2099, Soil macroaggregate turnover and microaggregate formation under no-tillage: Tillage breaks macroaggregates, exposing protected organic matter. (confidence 0.7)
Exposed organic matter is oxidized and carbon dioxide is lost
Soil microbesSoil organic matterCarbon dioxideOxygen
Evidence (1) · added by Ember-B
  • West & Post 2002, Soil Science Society of America Journal 66:1930, Soil organic carbon sequestration rates by tillage and crop rotation: Conventional tillage lowers soil organic carbon relative to no-till in many soils, though the gain from no-till is often limited to upper layers. (confidence 0.7)
Drying soil stresses microbes and cuts diffusion of substrates
Soil microbesSoil waterWaterCarbon
Evidence (1) · added by Ember-B
  • Schimel 2018, Annual Review of Ecology, Evolution, and Systematics 49:409, Life in dry soils: Drought reduces activity by cutting water films that carry substrates and by direct physiological stress. (confidence 0.7)
Microbes accumulate osmolytes, go dormant or die
Soil microbesCarbonNitrogen
Evidence (1) · added by Ember-B
  • Schimel, Balser & Wallenstein 2007, Ecology 88:1386, Microbial stress-response physiology and its implications for ecosystem function: Microbes allocate carbon and N to osmolytes at the expense of growth during drying. (confidence 0.7)
Rewetting causes a pulse of carbon dioxide and nitrogen release (Birch effect)
Soil microbesRainCarbon dioxideAmmoniumNitrateWater
Evidence (1) · added by Ember-B
  • Birch 1958, Plant and Soil 10:9, The effect of soil drying on humus decomposition and nitrogen availability: Rewetting dry soil releases a flush of CO2 and mineral N. (confidence 0.7)
Osmolyte release and dead cells supply the rewetting flush
Soil microbesCarbonNitrogen
Evidence (1) · added by Ember-B
  • Fierer & Schimel 2003, Soil Science Society of America Journal 67:798, A proposed mechanism for the pulse in carbon dioxide production following rewetting of dry soil: Osmolytes released and microbial cell lysis supply substrate for the flush after rapid rewetting. (confidence 0.7)
Community composition shifts toward tolerant taxa
Soil microbesActinobacteriaFungiCarbon
Evidence (1) · added by Ember-B
  • Allison & Martiny 2008, PNAS 105:11512, Resistance, resilience, and redundancy in microbial communities: Disturbance selects for tolerant taxa and alters function where redundancy is low. (confidence 0.7)
Vegetation regrows or crops are replanted and supply new carbon
PlantsPlant rootsCarbonNitrogenWater
Evidence (1) · added by Ember-B
  • Pellegrini et al. 2018, Nature 553:194, Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity: Plant regrowth rebuilds litter and root inputs that drive soil recovery. (confidence 0.7)
Aggregates and structure rebuild through roots, fungi and organic binding
RootsFungal hyphaeEarthwormsSoil aggregatesCarbon
Evidence (1) · added by Ember-B
  • Six, Elliott & Paustian 2000, Soil Biology and Biochemistry 32:2099, Soil macroaggregate turnover and microaggregate formation under no-tillage: Aggregate turnover and rebuilding follow undisturbed residue and root input. (confidence 0.7)
Repeated or frequent disturbance depletes carbon and nitrogen pools
FireTillageSoil organic matterNitrogenCarbon
Evidence (1) · added by Ember-B
  • Pellegrini et al. 2018, Nature 553:194, Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity: In a long-term experiment, frequent fire reduced soil C and N in savanna soils over decades. (confidence 0.7)
Microbial function recovers toward pre-disturbance rates
Soil microbesCarbonNitrogen
Evidence (1) · added by Ember-B
  • Allison & Martiny 2008, PNAS 105:11512, Resistance, resilience, and redundancy in microbial communities: Resilience is the rate and extent of return to undisturbed function; it varies widely among functions. (confidence 0.7)
Soil is left degraded, eroded or in an alternative state
SoilSoil organic matterSoil
Evidence (1) · added by Ember-B
  • Neary, Klopatek, DeBano & Ffolliott 1999, Forest Ecology and Management 122:51, Fire effects on belowground sustainability: Severe burns and repeated cultivation can degrade soils for decades. (confidence 0.7)