42–45 — PHYSICAL ENERGY ACCOUNTING
The bookkeeping layout should be:
Operational definition
Layer type: Quantitative conservation layer Governs: Items 42–45
Formal definition
The Physical Energy and Resource Accounting layer measures the quantities and rates of resources and energy entering, remaining within, leaving, or being transformed by a defined living system.
It is the bookkeeping layer of the taxonomy.
Governing question
How much enters, how much is assimilated, where does it physically go, and does the balance close?
Included accounting partitions
- gross resource acquisition;
- unassimilated fraction;
- assimilated fraction;
- changes in biomass;
- changes in reserves;
- exported chemical energy;
- metabolic products;
- dissipated heat.
Required specifications
Every valid measurement should specify:
- system boundary;
- time interval;
- units;
- resource or energy form;
- gross versus net quantity;
- stock versus flow;
- whether values are measured, modeled, or inferred.
Stock-versus-flow distinction
A stock is an amount present at a moment:
joules stored
grams of lipid
A flow is an amount per unit time:
joules per day
grams of carbon per square meter per year
Stocks and flows cannot be added without accounting for time.
Double-counting rule
Functional expenditures must not be naively added to heat as independent terminal destinations.
For example:
ATP used for movement
→
mechanical work
→
friction and heat
“Movement” identifies the function. Heat identifies the eventual physical fate. Counting both as independent terminal losses would count some energy twice.
Exclusion rule
This layer does not answer why the organism used the energy. That belongs to Functional Energy Allocation.
42. Resource acquisition
E_acquired
43. Unassimilated fraction
- rejected material
- undigested material
- fecal loss
- unused dissolved substrate
- reflected or uncaptured radiation
44. Assimilated fraction
E_acquired = E_unassimilated + E_assimilated
45. Fate of assimilated chemical free energy
E_assimilated = Δ E_biomass + Δ E_reserves + E_exported + E_metabolically dissipated
This is the cleaner physical balance.
The functional purposes of expenditure—maintenance, movement, defense, reproduction—should then be recorded separately, because summing functional categories and heat without a defined boundary can double-count the same energy.