What belongs in this system
Photon captureChlorophyllPhotosystemsElectron transportCalvin cycleCO₂ diffusionCarbohydratesSource-sink
Physiology Deep Lab · Evidence First
Photosynthesis & Carbon
Trace light capture, carbon dioxide diffusion, biochemical carbon fixation, carbohydrate production, and the movement of assimilates from source leaves to growing sinks.
What the system does
- Converts light energy into chemical energy
- Fixes atmospheric carbon into organic molecules
- Supplies carbon skeletons for growth
- Feeds roots, meristems, flowers, and storage tissues
What to record
- Leaf orientation and light exposure
- Canopy shading
- Growth response over time
- Leaf temperature and gas-exchange context
Keep connected causes in view
- Stomatal conductance affects CO₂ entry
- Water status can constrain carbon gain
- Temperature changes enzyme activity
- Sink demand influences carbohydrate allocation
Attach numbers to the observation
- PPFD
- DLI
- Photoperiod
- Leaf temperature
- Air temperature
- CO2 concentration when controlled
- Canopy position and shading
- Growth-rate trend
Test the explanation
- Is light actually limiting, or is another factor constraining carbon gain?
- Are leaf temperature, water status and CO2 context compatible with the observed response?
- Is source-sink demand changing with developmental stage?
Avoid single-symptom conclusions
- More light does not always mean more photosynthesis
- Leaf greenness is not a direct photosynthesis measurement
- Interpret light with CO₂, temperature, water status, canopy age, and acclimation
Evidence boundary: observation narrows plausible explanations; it does not prove a cause by itself. Use measurements, time course, comparisons, and appropriate testing before acting.
Leaf-to-chloroplast carbon pathway and source-sink map.
Measure the context
PPFD / Light Lab
Measure or map PPFD and calculate DLI while preserving sensor, geometry, photoperiod, and fixture context.Photoperiod Planner
Compare light-duration schedules without confusing photoperiod with photon intensity.Ventilation & CO₂ Reference
Document room-volume airflow planning and CO₂/ventilation context alongside light and carbon-assimilation questions.
Measure or map PPFD and calculate DLI while preserving sensor, geometry, photoperiod, and fixture context.Photoperiod Planner
Compare light-duration schedules without confusing photoperiod with photon intensity.Ventilation & CO₂ Reference
Document room-volume airflow planning and CO₂/ventilation context alongside light and carbon-assimilation questions.