Dynamic Energy Budgets

DEBparameters

An immutable struct to save the parameter list for a species' Dynamic Energy Budget model. (See Sousa et al., 2010.)

EnergyBudget

This struct represents an individual's energy balance, as conceptualised by the Dynamic Energy Budget theory. Upon assimilation, energy is first stored as biomass in a reserve buffer, before being used for maintenance, growth, and reproduction. (Note that this is a simplified model form which ignores maturity as a separate buffer.)

Sources:

• Malishev & Kramer-Schadt (2021). Movement, models, and metabolism: Individual-based energy budget models as next-generation extensions for predicting animal movement outcomes across scales. Ecological Modelling, 441, 109413. https://doi.org/10.1016/j.ecolmodel.2020.109413
• Marques et al. (2018). The AmP project: Comparing species on the basis of dynamic energy budget parameters. PLOS Computational Biology,14(5), e1006100. https://doi.org/10.1371/journal.pcbi.1006100
• Sibly et al. (2013). Representing the acquisition and use of energy by individuals in agent-based models of animal populations. Methods in Ecology and Evolution, 4(2), 151–161. https://doi.org/10.1111/2041-210x.12002
• Sousa et al. (2010). Dynamic energy budget theory restores coherence in biology. Philosophical Transactions of the Royal Society B: Biological Sciences, 365(1557), 3413–3428. https://doi.org/10.1098/rstb.2010.0166
• Kooijman, S. A. L. M. (2009). Dynamic energy and mass budgets in biological systems (3rd ed). Cambridge University Press. https://www.researchgate.net/profile/Edgar-Meza-3/post/Isthereatoxicokineticmodelfordaphniamagnaorotherzooplankton/attachment/59d62cf579197b807798b396/AS%3A348547653357569%401460111644286/download/Dynamic+Energy+Budget+theory+-+Kooijman.pdf
• compare with: Brown et al. (2004). Toward a metabolic theory of ecology. Ecology, 85(7), 1771–1789. https://doi.org/10.1890/03-9000

feed!(quantity, energybudget)

Consume a given quantity of food. Expands the energy reserve by an amount determined by the assimilation rate. Returns true if successful, false if the reserve is already full.

growthrate(energybudget)

Calculate the specific growth rate r. (Internal function.)

investmentratio(energybudget)

Calculate the investment ratio g. (Internal function.)

maturitymaintenance(energybudget)

Calculate the specific maturity maintenance k_J. (Internal function.)

mobilisation(energybudget)

Calculate the mobilisation rate J_EC. (Internal function.)

reproduce!(energybudget)

If there is sufficient energy in the offspring buffer of an adult, produce an embryo/egg, reducing the parent energy in the process. Returns the embryo's energy budget, or nothing if the conditions are not met.

scaledreservedensity(energybudget)

Calculate the scaled reserve density e. (Internal function.)

update!(energybudget)

Carry out a daily update of the energy budget. Mobilises reserves and allocates these to maintenance (prioritised), growth, and reproduction.

Return true if the individual has enough energy to survive, or false if the reserve is empty and it starves.

volumetriclength(energybudget)

Calculate the structural length in cm based on an individual's weight (assuming a density of 1 g/cm³ to calculate volume, see Kooijman 2009).