Each of the 324 plots on the grid holds a successional stage (bare soil → pioneer grass → shrub → young forest → mature forest) and a soil-health value h ∈ [0,1]. Every simulated week:
h(t+1) = h(t) + 0.05 · (target − h(t))
target = soilEffort − 0.3 · [invasive present]
advance stage if h > threshold[stage] and a planting event fires
P(plant event) = plantingRate · 0.05 per plot per week
invasive spreads to a healthy neighbor with
P(spread) = invasivePressure · 0.02 per edge per week
Canopy cover is the fraction of plots at young or mature forest stage. Biodiversity uses the Shannon diversity index over the five stage categories, normalised to the maximum possible entropy:
H' = −Σ pᵢ·ln(pᵢ) / ln(5), pᵢ = fraction of plots in stage i
Ten indicator species — from pollinator insects to apex predators — each need a minimum canopy cover and a minimum biodiversity index before they return, mirroring how real restoration projects track habitat structure and species diversity as recovery proxies rather than watching for animals directly.
- Native planting rate — how aggressively native species are being reintroduced; drives stage advancement.
- Invasive species pressure — how strongly invasives compete for the site; suppresses soil health and can spread plot-to-plot.
- Soil restoration effort — compost, erosion control, mycorrhizal inoculation; sets the soil-health target every plot recovers toward.
- Reset to Degraded Site — reseeds the plot back to a bare, partly invaded starting condition.