Transcript MELiSSA approach

Multi-scale approach as a
prerequisite for modeling
bioregenerative LSS: MELiSSA
approach
L. Poulet, J.-P. Fontaine, C.-G. Dussap
ISLSWG workshop, Turin
18 – 19 May 2015
MELiSSA Loop
MELiSSA Approach
• 5 output variables:
o O2 release
o CO2 fixation
o Dry mass quantity
o Dry mass composition
o Water transport
Functions of cultivar,
light, RH, T°, etc.
Needed to get information on mass & energy fluxes
on an overall scale
Mechanistic vs. Empirical
Level i
Plant
Empirical modeling
Analysis
reduction
Whole-plant
variables
Integration
synthesis
Mechanistic modeling
Level i-1
Organs
Tissues
Extra
variables
Source: Thornley and Johnson, 1990
Mechanistic model
Pros
- More phenomena studied
Cons
- Many assumptions might
induce less good fit of data
- More
possibilities
for
manipulating & improving -Not always practically feasible
system
(time and costs)
- Identifying knowledge gaps
- Not always applicable when
process not well known and
- Stimulation of new ideas for equations cannot be solved
experimental approaches
Inspired from Thornley and Johnson, 1990 and Mark J. Willis & Ming T. Tham, Advanced Process Control, Newcastle University, 2009
Higher Plant Compartment
Higher Plant Chamber, MELiSSA Pilot Plant,
Barcelona
Processes within a plant
Light
Storage
Light interception
Growth
Photosynthesis
Development,
Architecture &
Morphology
Gas exchange
Atmosphere
Sap ascent
Xylem Phloem
Respiration
Processes in a plant. Source: P. Hezard
Water + minerals
Temperature
Photoperiod
Growth
Root absorption
Mechanistic model of a plant
Process
Physical
Biochemical
Morphological
Module
Organ
Cell
Plant
Leaf
Stem
Root
Photosynthesis
Water transport
Root zone
- CO2 absorption
- Sugar production
- H2O evaporation
- O2 release
- Xylem: Water up
- Phloem: Sap down
- Xylem - Phloem
- Water & minerals
absorption
- Gravitropism
- Respiration
Environment
- Light flux
- Air: RH, O2, CO2, H2O
- Root zone: H2O, O2,
minerals
Growth: metabolic
reactions
- Link to biomass
- Gravitropism effects
Architecture
- Shape & structure
- Exchange surfaces
Conclusion
• BLSS modeling in MELiSSA
o Multi-scale approach – Mechanistic
o Necessity of understanding local phenomena
• Example of Higher Plants
o Multiple processes involved in plant growth
o Three main scales identified
o Physical, chemical and biochemical: ODEs,
sequential simulation, etc.
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