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Earth's Systems / Biological processes / Terrestrial ecosystem functioning / Water movement / Land water partitioning and plant water flux

Land water partitioning and plant water flux

How precipitation on land is divided between evapotranspiration and runoff, how large the plant share of that evaporative flux is, and how roots redistribute water through soil.

Boundary: where this process starts

Starts with: Roots take up water from layered soil

Boundary: where it ends

Ends after: Macropores let water bypass the soil matrix (preferential flow); Plant-mediated water flux

PARTICIPANTSRESOURCESPlantsSoilRainPlant rootsAtmosphereWaterWater vapourSolar energyImpact +3 of 5. Click for details and evidence.Impact +3 of 5. Click for details and evidence.Impact +4 of 5. Click for details and evidence.60% evapotranspirationImpact +3 of 5. Click for details and evidence.40% runoff and drainageImpact +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.Roots take up water from layered soil: uses up Wateruses upFate of precipitation on land: uses WaterEvapotranspiration returns water to the atmosphere: uses up Wateruses upEvapotranspiration returns water to the atmosphere: makes Water vapourmakesEvapotranspiration returns water to the atmosphere: uses Solar energyRunoff and groundwater recharge carry the remainder to rivers and aquifers: uses WaterMacropores let water bypass the soil matrix (preferential flow): uses WaterPlant-mediated water flux: uses WaterPlant-mediated water flux: uses Water vapourextracted from layers byrootsWater: extracted from layers by rootssplit among flow pathsWater: split among flow pathsreturned to air by ETWater: returned to air by ETreleased to theatmosphereWater vapour: released to the atmospheresupplies latent heatSolar energy: supplies latent heatrouted to rivers andaquifersWater: routed to rivers and aquifersrouted around the soilmatrixWater: routed around the soil matrixmoved through planttissueWater: moved through plant tissuereleased from leafstomataWater vapour: released from leaf stomataStart: Land waterpartitioning and plantwater fluxSTARTStart: Land water partitioning and plant water fluxEnd: Land waterpartitioning and plantwater fluxENDEnd: Land water partitioning and plant water fluxRoots take up waterfrom layered soil📄1Roots take up water from layered soilFate of precipitationon land📄1Fate of precipitation on landEvapotranspirationreturns water to theatmosphere👍1📄1Evapotranspiration returns water to the atmosphereRunoff and groundwaterrecharge carry theremainder to rivers a…📄1Runoff and groundwater recharge carry the remainder to rivers and aquifersMacropores let waterbypass the soil matrix(preferential flow)📄1Macropores let water bypass the soil matrix (preferential flow)Plant-mediated waterflux↘📄1Plant-mediated water flux
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)
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Participant
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Resource
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Inside this process

Plant-mediated water flux

Transpiration is the dominant part of evapotranspiration; roots also move water between wet and dry soil layers, extending the time plants can stay active.

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.

Roots take up water from layered soil
PlantsPlant rootsWater
Evidence (1) · added by Broad
  • Schenk & Jackson 2002, The global biogeography of roots, Ecological Monographs, doi:10.1890/0012-9615(2002)072[0311:tgbor]2.0.co;2: Root distributions with depth determine accessible soil water. (confidence 0.65)
⑂ Fate of precipitation on land
RainSoilPlantsWater
Evidence (1) · added by Broad
  • Oki & Kanae 2006, Global hydrological cycles and world water resources, Science, doi:10.1126/science.1128845: About 60% of land precipitation returns to the air as evapotranspiration; about 40% leaves as runoff and groundwater flow. (confidence 0.65)
Evapotranspiration returns water to the atmosphere
PlantsAtmosphereWaterWater vapourSolar energy
Evidence (1) · added by Broad
  • Oki & Kanae 2006, Global hydrological cycles and world water resources, Science, doi:10.1126/science.1128845: Evapotranspiration is the larger land flux. (confidence 0.7)
Runoff and groundwater recharge carry the remainder to rivers and aquifers
SoilGravityDrainage waterWater
Evidence (1) · added by Broad
  • Oki & Kanae 2006, Global hydrological cycles and world water resources, Science, doi:10.1126/science.1128845: About 40% of land precipitation leaves as runoff. (confidence 0.7)
Macropores let water bypass the soil matrix (preferential flow)
SoilEarthwormsPlant rootsWater
Evidence (1) · added by Broad
  • Beven & Germann 1982, Macropores and water flow in soils, Water Resources Research, doi:10.1029/wr018i005p01311: Macropore flow moves water and solutes rapidly past the matrix. (confidence 0.75)
↘ Plant-mediated water flux
PlantsPlant rootsWaterWater vapour
Evidence (1) · added by Broad
  • Jasechko 2013, Terrestrial water fluxes dominated by transpiration, Nature, doi:10.1038/nature11983: Transpiration is estimated to be 80-90% of terrestrial evapotranspiration. (confidence 0.7)