Garden Meal Days
GMD is a measure of RSD Sustainability/Survivability design layer performance. A human requires a certain amount of nutrition in a day that is delivered through a series of meals. We humans need 365 Meal Days in a year. The measure of a forest garden to produce an amount of nutrition per human per day is a Garden Meal Day.
For example: If the food forest provides 50% daily nutrition for 365 days of the year the GMD measurement is: 365 * 0.5 = 182 GMD.
Should the forest provide 75% daily nutrition for 242 days of the year then: 242 * .75 = 182 GMD.
Survivability design-layer requirements to meet self-sufficiency following an actualized catostrophic threat event scenario would require 365 GMD.