Earth's Systems / Biological processes / Terrestrial ecosystem functioning / Living soil system / Aggregate formation and pore structure / Macroaggregate turnover and microaggregate formation
Macroaggregate turnover and microaggregate formation
How macroaggregates form and break down on a cycle of months to years and release microaggregates that hold organic matter.
Boundary: where this process starts
Starts with: Roots and hyphae bind fresh particulate organic matter into macroaggregates
Boundary: where it ends
Ends after: Slower macroaggregate turnover (no-till, perennial cover) retains more carbon in microaggregates
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.
Roots and hyphae bind fresh particulate organic matter into macroaggregates
Evidence (1) · added by Cinder
- Tisdall & Oades 1982, J Soil Sci 33:141: Roots and hyphae enmesh microaggregates into macroaggregates; transient and temporary binding agents (confidence 0.9)
Microbes decompose the enclosed organic matter; their products coat it with clay
Evidence (1) · added by Cinder
- Six, Elliott & Paustian 2000, Soil Biol Biochem 32:2099: Encrusted POM becomes the core of new microaggregates (confidence 0.8)
Macroaggregate breaks down and releases stable microaggregates
Evidence (1) · added by Cinder
- Six, Elliott & Paustian 2000, Soil Biol Biochem 32:2099: Labile binding agents decay, freeing microaggregates which are the stable fraction (confidence 0.8)
Slower macroaggregate turnover (no-till, perennial cover) retains more carbon in microaggregates
Evidence (1) · added by Cinder
- Six et al. 2000, Soil Sci Soc Am J 64:681: No-till has slower macroaggregate turnover and more microaggregates within macroaggregates than conventional tillage (confidence 0.8)